Maternal polycystic ovary syndrome (PCOS) and autism yet again

Another mash-up post for you today as I bring two papers to the blogging table discussing a topic which has already had quite a bit of airtime on this blog: maternal diagnosis of polycystic ovary syndrome (PCOS) and risk of offspring diagnosis of autism (see here and see here). The papers in question are from Maria Katsigianni and colleagues [1] and Carolyn Cesta and colleagues [2] and, via different experimental means, both papers suggest that women with PCOS have a significantly greater risk of having a child diagnosed with autism or autism spectrum disorder (ASD).

PCOS, in case you didn't know, is a fairly common condition according to the NHS entry. It's characterised by three main features: irregular periods, the presence of high levels of androgens (male hormones) and polycystic ovaries ("ovaries become enlarged and contain many fluid-filled sacs (follicles) that surround the eggs"). Mention of (male) sex hormones in relation to PCOS have led quite a few researchers to suspect a connection between PCOS and autism but another important angle to the diagnosis is a link between PCOS and insulin (the hormone involved in blood sugar control)...

Anyhow, the Katsigianni paper first. This was a systematic review and meta-analysis of the existing peer-reviewed science on the topic of "whether women with PCOS have increased odds of having a child with ASD, while, secondarily, if these women themselves are at high risk of having the disease." Now just before anyone gets shirty with the use of the word 'disease', those are the authors words not mine. I fully go with the idea that autism is not a disease. Their 'boiling down the research literature' efforts yielded 10 studies which included over 30,000 children with autism and some 320,000 "non-ASD children." The results: "Diagnosed PCOS was associated with a 1.66 times increase in the odds of ASD in the offspring" and: "Women with PCOS were 1.78 times more likely to be diagnosed with ASD." Most data on which those findings were based were deemed to be of 'good quality'.

Then to the Cesta study. The primary aim was to "measure, in the general population, the association between maternal PCOS and offspring neuropsychiatric disorders where prenatal androgen levels and/or altered androgen function have been implicated in their etiology." That population was the Sweden, and yet another example of those fantastic Scandinavian population registries being put to good research use. Autism, by the way, wasn't the only label looked at by Cesta et al: "offspring attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD), and Tourette's disorder and chronic tic disorders (TD/CTD)."

Results: based on detecting some 20,000 PCOS-exposed offspring and 200,000 "unrelated PCOS-unexposed offspring" authors concluded that: "PCOS-exposed offspring had increased risk of being diagnosed with ADHD, ASD, and TD/CTD compared with unrelated PCOS-unexposed offspring." Interestingly Cesta observed that the association between maternal PCOS and autism and ADHD was stronger in girl offspring than boy offspring. They then go on to talk about prenatal androgen exposure "leading to ‘hyper-masculine’ behavioral and cognitive traits" in offspring as being one potential biological mechanism.

What's more to say? Well, despite the whole 'male sex hormone' *link* to autism I'd like to see a lot more investigation looking at biological mechanisms. Going back to the insulin link with PCOS, there is a requirement for further study in light of other findings (see here and see here). Insofar as implications for policy, well, preferential screening for autism in offspring when mum has a diagnosis of PCOS could be indicated. This adds to the growing number of other circumstances where such preferential screening seems to be indicated.

Oh, and there could be other areas of potential investigation to consider too (see here)...

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[1] Katsigianni M. et al. Maternal polycystic ovarian syndrome in autism spectrum disorder: a systematic review and meta-analysis. Molecular Psychiatry. 2019. March 13.

[2] Cesta CE. et al. Maternal polycystic ovary syndrome and risk of neuropsychiatric disorders in offspring: prenatal androgen exposure or genetic confounding? Psychol Med. 2019 Mar 12:1-9.

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"Maternal diabetes, especially GDM, is probably a risk factor for ADHD"

It's coincidental that as I write this post about the findings reported by Lifeng Zhao and colleagues [1] talking about how "Maternal diabetes, especially GDM [gestational diabetes mellitus], is probably a risk factor for ADHD [attention-deficit hyperactivity disorder]" so the BBC news website highlights how screening for gestational diabetes here in Blighty is still a bit of a hit-and-miss affair (see here).

That news report mentions how about a quarter of those mums-to-be who are most at risk of developing pregnancy diabetes - "having a high BMI [body mass index] or being of South Asian or Black Caribbean ethnicity" - did not get screened at all. Left untreated, gestational or pregnancy diabetes can increase the risk of various adverse events including "a baby that grows larger than usual, leading to problems in labour; premature birth; pre-eclampsia and stillbirth."

The Zhao findings - a meta-analysis - continue a theme suggesting that exposure to maternal diabetes, including pregnancy diabetes, seems to increase the risk of various other developmental and behavioural diagnoses also being present in offspring. The primary source material of this blog - autism - has been talked about on various occasions as being one of those developmental/behavioural diagnoses (see here and see here). That ADHD is quite often mentioned in the diagnostic mix when it comes to autism (see here) is another point to make.

The basics of the Zhao paper: a search of the peer-reviewed science literature was undertaken revealing nine studies that fitted the inclusion criteria including "7,218,903 participants." The quality of most studies was ranked as high. The results were interesting in that researchers "did not find significant association between maternal diabetes and ADHD risk (OR: 1.20, 95% CI: 0.96–1.49)." This observation is slightly at odds with the quote titling this post, which Zhao et al put down to the "high heterogeneity" detected among the included studies and their subgroup analysis of case-control studies (n=3).

Also... when it came to looking at another type of study - a cohort study (n=6) - "the meta-analysis demonstrated that maternal diabetes increased the risk of ADHD in offspring by 40%." Further, and bearing in mind the description 'diabetes' covers quite a bit of diagnostic ground, authors zoomed in on one particular 'type of diabetes', that called gestational diabetes (GDM) and looked at any effect. This is where things got a little more interesting as their results, based on four studies, indicated that "GDM exposure increased the risk of ADHD for children by 164%" in Caucasian children. Ergo, although a little mixed, the existing research literature at the time of analysis indicated that maternal diabetes during pregnancy, particularly GDM, *might* have some important effect on risk of offspring ADHD.

I'm not going to say much more at this point in time in terms of potential mechanisms that *might* elevate the risk of ADHD in offspring exposed to pregnancy diabetes. It's likely to be pretty complicated. Given also that GDM appears more often than not alongside other conditions (see here), it's not going to be easy to tease apart what might be the more important issues. Is it inflammation? Is something to do with blood sugar or insulin? At the moment, we just don't know enough...

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[1] Zhao L. et al. The association of maternal diabetes with attention deficit and hyperactivity disorder in offspring: a meta-analysis. Neuropsychiatr Dis Treat. 2019;15:675–684.
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"To examine associations between early developmental exposure to ambient pesticides and autism spectrum disorder"

The quote heading this post - "To examine associations between early developmental exposure to ambient pesticides and autism spectrum disorder" - reflects the aim of the study published by Ondine von Ehrenstein and colleagues [1]. Said aim was accomplished by examining data from "California’s main agricultural region, Central Valley, using 1998-2010 birth data from the Office of Vital Statistics" with regards to autism diagnoses (see here) and pesticide use and exposure. The results: "Findings suggest that an offspring’s risk of autism spectrum disorder increases following prenatal exposure to ambient pesticides within 2000 m of their mother’s residence during pregnancy, compared with offspring of women from the same agricultural region without such exposure." Also: "Infant exposure could further increase risks for autism spectrum disorder with comorbid intellectual disability."

The von Ehrenstein findings also come with an accompanying editorial [2] both published in the British Medical Journal (BMJ). That editorial provides a good overview of the findings and, importantly, some of their limitations. The editorial notes for example, that: "the study included only children with a diagnosis of “autistic disorder” by the California Department of Developmental Services, based on criteria described in the Diagnostic and Statistical Manual of Mental Disorders version IV-R." It cautions that the von Ehrenstein findings might not generalise to "milder forms of autism spectrum disorder." This 'lack of generalisation to milder forms' is a real reversal of what is typically seen in the peer-reviewed autism research literature (see here).

I don't want to linger too much on the von Ehrenstein study but a few points are worth noting. The question of what specific pesticides *might* influence risk of offspring autism is a complicated one. The researchers reported that "small to moderately increased risks for the disorder in offspring with prenatal exposure to the organophosphates chlorpyrifos, diazinon, and malathion, the pyrethroids permethrin and bifenthrin, as well as to glyphosate, avermectin, and methyl bromide" were observed. They (and the editorial) talk about how further research is required to "examine the joint effects of multi-exposure mixtures to more effectively protect human health." This is important in the context of other research (see here and see here) and also to avoid any big media headlines (see here) about specific preparations 'causing' autism (which has not yet been authoritatively established). Given that various different classes of pesticides have somewhat slightly different biological actions, there is a lot of work to be done on the possible biological mechanisms/targets and any synergistic effects.

Also: "children with autism spectrum disorder and co-occurring intellectual disability were examined as a separate outcome." The fact that von Ehrenstein et al observed something like a 'stronger association' between pesticide exposure and those at the "more severe end of the autism spectrum" (the description according to one media source) is another important point requiring further study. I say this in the context that 'comorbidity' might not always be the best description for symptoms and diagnoses accompanying autism (see here).

The authors conclude that their findings - with appropriate caveats - have implications. Namely: "Exposure of pregnant women and infants to ambient pesticides with a potential neurodevelopmental toxicity mode of action should be avoided as a preventive measure against autism spectrum disorder." I don't think too many people would disagree with the sentiments of 'avoiding pesticide exposure' particularly for pregnant women and those who might also be more vulnerable to their potential effects. The questions now turn to genetics and biology and the question of why...

Music to close: Hostiles on the Hill (apparently)...

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[1] von Ehrenstein OS. et al. Prenatal and infant exposure to ambient pesticides and autism spectrum disorder in children: population based case-control study. BMJ. 2019; 364: I962.

[2] Bakian AV. & VanDerslice JA. Pesticides and autism. BMJ. 2019; 364: I1149.

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"maternal obesity and overweight were significantly associated with [offspring] increased ASD risk"

The title heading up this brief post - "maternal obesity and overweight were significantly associated with [offspring] increased ASD [autism spectrum disorder] risk" - comes from the results published by Xian-Yang Lei and colleagues [1].

Under systematic review and meta-analysis conditions, researchers basically found what many people had suspected for quite a while, insofar as maternal weight, before or during pregnancy, being a 'risk factor' for an offspring diagnosis of autism or ASD. They arrived at their conclusion based on "13 eligible studies for meta-analysis (involving 943,293 children and 30,337 cases)" which collectively found that "both maternal obesity... and maternal overweight... were significantly associated with ASD, while maternal underweight was not associated with ASD." Researchers also looked at paternal weight as a possible risk factor for offspring autism but found no statistical association between paternal obesity, overweight or underweight based on the available data (limited to only three studies).

Mindful of the potential for 'stigma' to set in with such investigation, and likewise being careful not to generalise too much from such findings, the Lei results point to both the requirement for more research in this area and a possible 'intervention' route towards reducing the risk of offspring autism: "pre-pregnancy weight control is suggested." I've covered this topic numerous times on this blog (see here and see here and see here for examples) and have concluded that whilst correlation is not the same as causation and that pre- and peri-pregnancy weight is often intricately tied into other features of the condition known as metabolic syndrome, immune function and in particular inflammation, are perhaps important areas for further assessment. Research should perhaps head in that direction, and see what further crops up...

And as if to further prove the point [2]...

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[1] Lei XY. et al. Association between parental body mass index and autism spectrum disorder: a systematic review and meta-analysis. Eur Child Adolesc Psychiatry. 2018 Nov 23.

[2] Windham GC. et al. Maternal Pre-pregnancy Body Mass Index and Gestational Weight Gain in Relation to Autism Spectrum Disorder and other Developmental Disorders in Offspring. Autism Res. 2018 Dec 21.

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"maternal pre-pregnancy obesity is associated with autism-like behaviors in offspring"

The results reported by Kandice Varcin and colleagues [1] concluding that "maternal pre-pregnancy obesity is associated with autism-like behaviors in offspring" continue and extend a research theme (see here and see here). A research theme that highlights a potentially important relationship between maternal weight (and/or related parameters) and offspring development across various, potentially intertwined, variables (see here).

Including the notable name of Andrew Whitehouse on the authorship team (see here and see here for some examples of his other research), researchers set about to explore whether "pre-pregnancy weight was related to autistic-like traits among offspring not diagnosed with ASD [autism spectrum disorder]." I added the bold highlight to the word 'not' to emphasise how this work was set slightly apart from the other research that has observed an *association* between maternal weight before or during pregnancy and a risk of a formal diagnosis of autism in offspring. Pregnant women in their second trimester of pregnancy were recruited and "had their height measured." They also "reported their pre-pregnancy weight" which combined with the height measurements to give the measure known as the body mass index (BMI). And also: "At 19-20 years of age, 1238 offspring of these women completed a measure of autistic-like traits, the Autism-Spectrum Quotient (AQ)." Keep those issues in mind for now.

Results: "Regression analyses identified a positive association between increasing maternal pre-pregnancy BMI and increasing AQ Total Score amongst offspring; this association was maintained even after controlling for a range of variables including maternal/obstetric factors (age at conception, education, smoking, alcohol consumption, hypertensive diseases, diabetes, threatened abortion), paternal BMI at pregnancy, and child factors (parity, sex)." Sorry for the large quote, but the authors said it better than I ever could. Authors also reported that those women defined as being obese before pregnancy, according to their BMI measurement, were quite a bit more likely to "have offspring with high scores (≥26) on the AQ." This then lead them to conclude that "maternal pre-pregnancy obesity is associated with autism-like behaviors in offspring."

Caveats? Well, yes, a few. Height measured in the second trimester but participants "reported their pre-pregnancy weight"? I can see a few complications there in terms of accuracy of recall and perhaps the possibility of some bias creeping in. Having said that, many mums-to-be do have records of their weight during that 'special time' and some probably before as part of their regular clinical care or just as a result of how health conscious everyone is being these days. That and the fact that most people roughly know their typical weight (outside of pregnancy).

But also the AQ... the AQ. Regular readers probably already know that I have some qualms about the AQ and it's 'specificity' when it comes to autism and autistic traits (see here and see here). I know it's often seen as one of the internet's premier 'are you autistic?' instruments, but sometimes I think it's done more harm than good by way of it's probable link to the rise and rise of the 'self diagnosis' (see here) for example. I could go on about this, but I won't. Instead I'll just mention that 'autism-like' behaviours as judged by the AQ is probably the correct phrase to use in the context of the Varcin paper. Indeed, one might easily suggest that in a non-clinical population, AQ might also be tapping into other labels and traits [2]: "Higher AQ scores were associated with higher scores of loneliness, social anxiety, depression, and anxiety, as well as with lower scores of quality of life (QoL)." So unless one accepts that depression and/or anxiety might potentially be core features of autism (see here and see here), AQ might be picking up other things other than autism.

Still, I can't argue with the *association* talked about by Varcin et al, and what it might mean for the quite spectacular rise and rise in the numbers of people being diagnosed with an autism spectrum disorder (see here). No, not by any means the only factor to account for the increase in diagnoses, but potentially an important part of the story...

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[1] Varcin KJ. et al. Maternal pre-pregnancy weight and autistic-like traits among offspring in the general population. Autism Res. 2018 Sep 19.

[2] Reed P. et al. Loneliness and Social Anxiety Mediate the Relationship between Autism Quotient and Quality of Life in University Students. Journal of Developmental and Physical Disabilities. 2016; 28: 723-733.

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Maternal and child immune disease and autism or other developmental disorder

The paper by Lisa Croen and colleagues [1] provides the brief blogging fodder today and some further results from the Study to Explore Early Development (SEED) initiative based in the United States. Whilst SEED has already produced quite a bit of peer-reviewed research data (see here), this time around the focus was on "the role of family history of autoimmune diseases, asthma, and allergies in autism spectrum disorder (ASD) as well as other developmental disorders (DD)." Yep, immune function yet again (see here).

Researchers mention how following their analysis of some 660 children with ASD, nearly a thousand children with DD and over 900 not-autism, not-DD population (POP) controls, they turned up some potentially important *associations* pertinent to immune system related conditions potentially elevating the risk of autism and/or DD. So: "Maternal history of eczema/psoriasis and asthma was associated with a 20%-40% increased odds of both ASD and DD" and "children with ASD were more likely to have a history of psoriasis/eczema or allergies than POP controls." Conversely, they did not detect any statistically significant associations between "paternal history or family history of these immune conditions for either ASD or DD."

I'm gonna leave things there for now on this topic. The immune system seems to be related to at least 'some' autism. There's nothing particularly new or novel about that sentiment but it does cover an awful lot of ground. A lot more research is required on the 'hows-and-whys' (see here for one example research route) and whether intervening on various immune system related conditions, one *might* also impact on the presentation of behaviour too...

And on the topic of intervention, may I also draw your attention to the mammoth paper by Marchezan and colleagues [2] reviewing the many and varied (evidence-based) intervention methods that are available as and when immune system issues crop up in the context of autism?

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[1] Croen LA. et al. Family history of immune conditions and autism spectrum and developmental disorders: Findings from the study to explore early development. Autism Res. 2018 Aug 10.

[2] Marchezan J. et al. Immunological Dysfunction in Autism Spectrum Disorder: A Potential Target for Therapy. Neuroimmunomodulation. 2018. Sept 5.

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Hypertensive disorders of pregnancy (HDP) and offspring autism and/or ADHD meta-analysed

"Pooled estimates from this systematic review and meta-analysis of 61 studies suggest that exposure to hypertensive disorders of pregnancy is associated with a small yet statistically significant increase in the odds of autism spectrum disorder and attention-deficit/hyperactivity disorder in offspring compared with no exposure."

So concluded the review and meta-analysis published by Gillian Maher and colleagues [1] that collected and analysed the current peer-reviewed research literature (up to June 2017) looking at hypertensive disorders of pregnancy (HDP) and offspring developmental outcomes. Continuing an important research theme (see here), authors observed something around "a 35% increased odds of ASD [autism spectrum disorder] compared with nonexposure" and that children were "30% more likely to have ADHD compared with unexposed offspring."

HDP according to Maher et al, covers quite a bit of diagnostic ground: "chronic hypertension (essential/secondary), white-coat hypertension, masked hypertension, transient gestational hypertension, gestational hypertension, and preeclampsia (de novo or superimposed on chronic hypertension)." The primary characteristic is "high blood pressure that either precedes pregnancy, is diagnosed within the first 20 weeks of pregnancy, or does not resolve by the 12-week postpartum checkup" [2].

There's little more to say about this area of research aside from the idea that findings "highlight the need for greater pediatric surveillance of infants exposed to HDP to allow early intervention that may improve neurodevelopmental outcome" and that more work on possible mechanism(s) need to be undertaken. On that last point the authors opine that "placental dysfunction, associated with HDP, may result in reduced placental perfusion and oxidative stress" or that: "Maternal inflammation may also play a key role." Both worthy areas for future research. The implication also, is that yet again, there may be some form of 'foetal programming' going on with regards to offspring autism that *could* be sensitive to intervention at some point...

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[1] Maher GM. et al. Association of Hypertensive Disorders of Pregnancy With Risk of Neurodevelopmental Disorders in Offspring: A Systematic Review and Meta-analysis. JAMA Psychiatry. 2018 Jun 6.

[2] Mammaro A. et al. Hypertensive Disorders of Pregnancy. Journal of Prenatal Medicine. 2009;3(1):1-5.

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Pregnancy diet and offspring "hyperactivity-inattention symptoms"?

I appreciate that the findings reported by Cédric Galera and colleagues [1] are potentially a little uncomfortable. Their examination of over 1200 mother-child pairs looking at data from food frequency questionnaires during pregnancy and subsequent offspring 'externalising' behaviours into childhood, could be construed as evidence that poor eating habits during the nine months that made us have the ability to translate into childhood issues. Because food choices are seen as just that - 'choices' - the Galera results *could* potentially fall into the same category as other 'choices' that also seemingly affect offspring development in this area (see here for example). I make no value judgements.

Having also bumped into the Galera paper at the same time as seeing a BBC media report observing that "We learn nothing about nutrition, claim medical students", one might further make an argument for the need for much greater education, guidance, support and potentially 'nudging', when it comes to issues such as 'what to eat during pregnancy'. That however, is another discussion for another day.

Anyhow, the science...

Galera et al report findings based on the EDEN mother-child cohort [2], an initiative set up to examine "the relations and potential interactions between maternal exposures and health status during pregnancy, fetal development, health status of the infant at birth and the child’s health and development." It's interesting that the opening words to the Heude [2] description of the initiative mention the name 'Barker', as in the late David Barker, a man who helped popularise the idea that nutrition in the womb (through maternal diet) might have some important *consequences* for offspring in the short- and long-term. Looking at some of the other research produced by the EDEN mother-child cohort (see here), Barker and others may have indeed been on to something.

As well as looking at offspring externalising symptoms such as conduct problems via use of "the Strength and Difficulties Questionnaire at ages 3, 5, and 8 years", authors also looked at "trajectories of hyperactivity-inattention symptoms." This, on the basis that the SDQ does pretty well at discriminating between ADHD and non-ADHD cases [3]. They concluded that, taking into account infant dietary patterns "at age 2 years" and various other potential influencing variables ("maternal stress and depression, gestational diabetes, and socioeconomic variables"), there was something to see with regards to use of a 'high Western diet' and 'low Healthy diet' during pregnancy in relation to offspring developmental outcome. Specifically: "Maternal diet during pregnancy was independently associated with children's hyperactivity-inattention symptoms."

Of course, one needs to be a little bit careful that *association* is not viewed as 'cause-and-effect' based on such observational studies. That also it is downright unethical to put mums-to-be on a 'healthy diet' vs. 'a non-healthy diet' is also a stumbling block to robust investigations in this area; similar to the fact that one wouldn't put mums-to-be on a tobacco smoking vs. a non-smoking intervention.

But the Galera results are not stand-alone in potentially implicating maternal diet as a factor in relation to offspring hyperactivity-inattention [4] and are therefore deserving of some further investigation. I've already mentioned that perhaps more guidance and 'nudges' need to be provided in the area of pregnancy nutrition, and that I assume, would include looking at the cost and convenience of a healthy diet vs. a not-so-healthy diet in the context of a possible *link* between diagnosed attention-deficit hyperactivity disorder (ADHD) and "socioeconomic deprivation" for example (see here). More than that however is the idea that David Barker and others who talked about 'foetal programming' during the pregnancy months as a result of what is in or perhaps not in a maternal diet may have been a lot more accurate than many people would have perhaps imagined...

And on the topic of 'foetal programming', diet might not be the only factor to consider [5]...

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[1] Galera C. et al. Prenatal diet and children's trajectories of hyperactivity-inattention and conduct problems from 3 to 8 years: the EDEN mother-child cohort. J Child Psychol Psychiatry. 2018 Mar 24.

[2] Heude B. et al. Cohort Profile: The EDEN mother-child cohort on the prenatal and early postnatal determinants of child health and development. Int J Epidemiol. 2016 Apr;45(2):353-63.

[3] Algorta GP. et al. Diagnostic efficiency of the SDQ for parents to identify ADHD in the UK: a ROC analysis. Eur Child Adolesc Psychiatry. 2016 Sep;25(9):949-57.

[4] Rijlaarsdam J. et al. Prenatal unhealthy diet, insulin-like growth factor 2 gene (IGF2) methylation, and attention deficit hyperactivity disorder symptoms in youth with early-onset conduct problems. J Child Psychol Psychiatry. 2017 Jan;58(1):19-27.

[5] Andersen SL. et al. Maternal Thyroid Function in Early Pregnancy and Child Neurodevelopmental Disorders: A Danish Nationwide Case-Cohort Study. Thyroid. 2018 Mar 27.

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Effects of pregnancy vitamin D deficiency on social behaviours of offspring rats

I note the findings reported by Nathanael Yates and colleagues [1] have garnered a few lay and science media headlines recently (see here) as authors concluded that "early life levels of vitamin D are an important consideration for maternal behavioural adaptations as well as offspring neuropsychiatry." Further coverage of their findings is provided in a helpful article for The Conversation (see here), where some authors - including the autism research powerhouse that is Andrew Whitehouse - provide a little more interpretation of their findings. I might also add that Whitehouse is no stranger to the vitamin D - autism research story (see here).

So, what's all the current discussion about?

Well, vitamin D - the 'sunshine' vitamin/hormone - is front and centre of this latest research, and some investigation into "how early life vitamin D deficiency during rat pregnancy and lactation alters maternal care and influences neurodevelopment and affective, cognitive and social behaviours in male adult offspring." This is set within the context that vitamin D seems to be doing a lot more than just contributing to bone health (see here). You'll of course note the use of the word 'rat' in the above text, and in particular what happened to offspring baby rats in terms of "offspring neurodevelopmental markers, ultrasonic vocalisations and adult behavioural outcomes including social, cognitive and affective-like behaviours" when mummy rat diets are loaded up with enough vitamin D as opposed to those mummy rats who were provided with a vitamin D deficient diet. The theory behind those vitamin D loaded vs. vitamin D deficient mummy rat diets is that: "In both humans and rats, a baby developing in the womb is completely reliant on the mother’s vitamin D stores." Probably something to do with the lack of sunlight exposure in the womb(!)...

Results: there did seem to be some difference across various 'test a rat / test an offspring rat' measures as a function of vitamin D status, looking across behaviour, brain scans (yes, rats did meet some MRI equipment) and also "plasma corticosterone levels and neural expression of genes associated with language, dopamine and glucocorticoid exposure." So for example, authors describe how "males that had been exposed to vitamin D deficiency in early life exhibited decreased social behaviour, impaired learning and memory outcomes and increased grooming behaviour, but unaltered affective behaviours." It's not difficult to see the 'decreased social behaviour' links that *could* be made with a condition / label / diagnosis like autism; particularly when vitamin D has quite the peer-reviewed research history with autism in mind (see here).

Interestingly too, but not made too much of in the chatter about this study for obvious reasons, were the observations made around maternal care as a function of vitamin D status, bearing in mind that vitamin D deficiency will probably impact both mummy rat and baby rat. So: "the quality of maternal care was decreased in dams consuming a vitamin D-deficient diet." Mmm...

Whilst this is important work, and adds to our understanding that appropriate nutrition throughout the lifespan is important to various aspects of functioning, I'll reiterate that this was research using rats. Rats not humans. It is perhaps timely that at around the same time that the Yates paper was published, I also chanced upon some discussion over at Spectrum on how we all need to be a little bit careful when talking about modelling autism in various animals (see here) and their relevance to real, often much more complicated, people (see here) and their [multiple] labels (see here).

I note that in their piece for the The Conversation, authors caution that their findings don't mean everyone who is pregnant (or could become pregnant) should rush out and load up on vitamin D so as to potentially influence offspring developmental course. I would second that view; but would also direct your attention to some Government advice quite recently (at least here in Blighty) that we should perhaps all be thinking about vitamin D supplementation (see here) and the many and varied ways that this vitamin/hormone *might* impact on our physiology and beyond (see here).

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[1] Yates NJ. et al. Vitamin D is crucial for maternal care and offspring social behaviour in rats. J Endocrinol. 2018 May;237(2):73-85.

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"Low parental melatonin levels could be one of the contributors to ASD and possibly ID etiology"

The title heading this post - "Low parental melatonin levels could be one of the contributors to ASD and possibly ID etiology" - comes from the findings reported by Wiebe Braam and colleagues [1]. It continues a research theme on the topic of melatonin and autism or autism spectrum disorder (ASD) (and intellectual disability, ID) (see here).

Perhaps most famously known for its links to circadian rhythms, melatonin is quite an important topic in many areas of autism research and practice. The use of melatonin to influence various sleep issues that seem to be quite regularly present in relation to autism (see here) takes the lion's share of the limelight (see here) but this is a compound potentially doing sooo much more. I've for example, talked about melatonin in relation to intestinal permeability issues (see here) on this blog, as this molecular handyperson [2] offers several possible links/effects with other biological systems. Indeed, Braam et al start from a position where melatonin "is important for normal neurodevelopment and is highly effective in protecting DNA from oxidative damage" continuing an interest for members of the authorship group.

The current findings have, I believe, been seen before on the preprint server bioRxiv [3] so we knew this peer-reviewed publication was coming. Including urine samples from 60 mothers of children diagnosed with autism and a somewhat smaller number from control mothers (with no children diagnosed with autism), researchers submitted said urine samples to analysis for a compound called 6-sulfatoxymelatonin, a primary urinary metabolite of melatonin. I understand that the gold-standard analytical method that is mass spectrometry was the chosen way to determine urinary 6-sulfatoxymelatonin, so one has some confidence that researchers were detecting/measuring this metabolite pretty accurately.

Researchers reported that levels of urinary 6-sulfatoxymelatonin were lower in mums of children diagnosed with autism compared to controls. This finding mirrors that reported in young people with autism [4] and, on more than one research occasion [5]. It looks like there may be a familial element to some of the issues with melatonin which quite neatly fits into other work suggesting similar things with other biological systems including that intestinal permeability [6] that I just mentioned.

Insofar as the implications and 'where next?' questions arising from such work, they are potentially numerous. The relationship with sleep and circadian rhythms is an obvious starting point. Further exploration of whether maternal melatonin biochemistry could be a *risk* factor for similarly altered biochemistry in relation to offspring with autism is also indicated. I'd also like to see some data on paternal and sibling levels of compounds such as 6-sulfatoxymelatonin too (and their related compounds) and how that might correlate with issues such as sleep in those populations.

The inclusion of the word 'sulfate' in 6-sulfatoxymelatonin might also lead to another area of possible research inspection with autism in mind. I hark back to work conducted seemingly aeons ago talking about how sulfate/sulphate chemistry might show some connection to some autism (see here). Sulfation is an important part of the reaction forming 6-sulfatoxymelatonin: 6-hydroxylation --> 6-hydroxymelatonin --> 6-sulfatoxymelatonin (I think), which would be reliant on there being enough sulphate to successfully produce such a reaction on a suitably large scale.

And finally, minus scaremongering or any sweeping generalisations, I do wonder whether further research needs to be done in a wider context of low urinary 6-sulfatoxymelatonin levels. I speak for example of research such as that by Devore and colleagues [7] talking about "Higher urinary melatonin levels... suggestively associated with a lower overall risk of breast cancer." This, in the context that such health issues have been reported with autism mentioned (see here); something which also requires a lot more scientific investigation...

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[1] Braam W. et al. Low maternal melatonin level increases autism spectrum disorder risk in children. Research in Developmental Disabilities. 2018. March 1.

[2] Boga JA. et al. Beneficial actions of melatonin in the management of viral infections: a new use for this "molecular handyman"? Rev Med Virol. 2012 Sep;22(5):323-38.

[3] Braam W. et al. Low parental melatonin levels increases autism spectrum disorder risk in children. bioRvix. 2016. April 2.

[4] Tordjman S. et al. Day and nighttime excretion of 6-sulphatoxymelatonin in adolescents and young adults with autistic disorder. Psychoneuroendocrinology. 2012 Dec;37(12):1990-7.

[5] Tordjman S. et al. Nocturnal excretion of 6-sulphatoxymelatonin in children and adolescents with autistic disorder. Biol Psychiatry. 2005 Jan 15;57(2):134-8

[6] de Magistris L. et al. Alterations of the intestinal barrier in patients with autism spectrum disorders and in their first-degree relatives. J Pediatr Gastroenterol Nutr. 2010 Oct;51(4):418-24.

[7] Devore EE. et al. Urinary Melatonin in Relation to Postmenopausal Breast Cancer Risk According to Melatonin 1 Receptor Status. Cancer Epidemiol Biomarkers Prev. 2017 Mar;26(3):413-419.

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Pre-eclampsia increased the risk of ASD in offspring: meta-analysed

"The finding suggests a need for early screening for ASD [autism spectrum disorder] in offspring of women with pre-eclampsia."

That was the conclusion reached in the meta-analysis published by Berihun Assefa Dachew and colleagues [1] covering the literature on pre-clampsia and offspring risk of autism or ASD.

Pre-eclampsia refers to a condition/state typically occurring after about 20 weeks of pregnancy. It is characterised by a combination of symptoms including hypertension (raised blood pressure) and the presence of protein in the urine (proteinuria).

On the basis that pre-eclampsia has been mentioned as a *possible* risk factor for subsequent offspring autism diagnosis (see here), the authors set about meta-analysing the peer-reviewed research in this area covering the period up to the middle of March 2017. They eventually settled on 10 studies that suitably covered the topic; of which 5 were rated as 'good in methodological quality' and the rest, somewhere between fair and poor.

Results: most studies (7/10) reported a positive association between the presence of pre-eclampsia and offspring autism. Most studies included for meta-analysis had taken into account some potentially important confounding variables such as child gender, "maternal age and substance use during pregnancy." The overall enhanced risk of offspring autism - "pooled relative risk (RR)" - associated with intrauterine exposure to pre-eclampsia was 32% compared with non-exposed children. And with that, you can perhaps see why the authors make that call for preferential screening for autism in children exposed to pregnancy pre-eclampsia.

But one must also be a little careful with such results. Careful because studies were usually looking at one pregnancy variable and one offspring outcome. To quote the authors, studies typically "did not consistently adjust for important confounding factors such as maternal obesity, parity, gestational diabetes and infection during pregnancy" all of which have been mentioned with offspring autism risk in mind (see here and see here and see here and see here respectively). Lots of things go on during pregnancy (and indeed, before pregnancy) that *could* have a sizeable impact - alone or in combination with each other - on various offspring outcomes including risk of a diagnosis of autism.

Still the results are what they are. They invite further investigations in this area, including those relevant to the possible hows-and-whys of pre-eclampsia exposure potentially contributing to a developmental/behavioural diagnosis and what strategies might be useful to consider [2] more generally...

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[1] Dachew BA. et al. Pre-eclampsia and the risk of autism-spectrum disorder in offspring: meta-analysis. British Journal of Psychiatry. 2018. Jan 24.

[2] Nordqvist M. et al. Timing of probiotic milk consumption during pregnancy and effects on the incidence of preeclampsia and preterm delivery: a prospective observational cohort study in Norway. BMJ Open. 2018; 8: e018021.

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Maternal diabetes and offspring autism risk meta-analysed

"Maternal diabetes, especially gestational diabetes mellitus, is associated with ASDs [autism spectrum disorders] in offspring based on a limited number of convincing case-control studies. More large-scale population-based prospective studies are still needed to draw firm conclusions."

So concluded the systematic review and meta-analysis by Hongquan Wan and colleagues [1] taking on an important question: does maternal diabetes confer an enhanced risk of offspring autism? Diabetes by the way, covers quite a bit of diagnostic ground, but is typically characterised by elevations in blood sugar levels and the various ways that this can (and does) affect biology and risk of some important adverse conditions.

Yes, appears to the answer based on the peer-reviewed research literature so far (until June 2017) with regards to maternal diabetes affecting offspring autism risk; although with it, a greater need to confirm such findings and also elucidate possible genetic and biological pathways linking diabetes exposure and offspring autism risk is required. I might add that having covered this topic a few times on this blog (see here and see here), including discussing other meta-analysis results [2], I'm not all that surprised by the findings.

Wan et al report results based on 12 articles - "7 were case-control studies... and 5 were cohort study." Combining results in a meta-analytic fashion produced some important observations: "The overall analysis demonstrated that gestational diabetes increased the risk of ASD by 48%" and when reliant on "case-control studies with moderate... or high quality [standing]", the risk increased to over 60%. In short, maternal diabetes exposure does seem to have something of an important effect on offspring risk of autism.

Mechanism(s) of effect? Well, the authors do provide some summary of hypotheses previously put forward. Diabetes exposure causing "brain malformation and aberrant neurodevelopment" is one theory; with words such as "enhanced cell apoptosis and activated oxidative stress" also included. Even possible immune system effects gets some airtime; as the discussion also turns to "the presence of autoantibodies" as a potentially important variable. Autoantibodies, I might add, are part and parcel of at least one type of diabetes. I might also throw in the idea of foetal programming as an over-arching concept to perhaps keep in mind and with it, the implication that early and timely diagnosis and management of maternal diabetes both before and during pregnancy *could* potentially affect offspring autism risk. *Could* is the operative word there...

But... alongside all the 'we need more and better research in this area' sentiments, I'm also minded to highlight how maternal diabetes - in all it's forms - is not necessarily a stand-alone condition. Indeed, it's an important point to remember that when talking about pregnancy factors in the context of something like offspring autism risk, there could be a range of separate but overlapping issues to contend with (see here and see here for examples) which complicate any attempts to single out particular variables as being more or less important when it comes to offspring outcomes.

It's also unwise to assume that 'all autism' is somehow conception or pregnancy-associated either (see here and see here)...

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[1] Wan H. et al. Association of maternal diabetes with autism spectrum disorders in offspring: A systemic review and meta-analysis. Medicine. 2018' 77: e9438.

[2] Xu G. et al. Maternal diabetes and the risk of autism spectrum disorders in the offspring: a systematic review and meta-analysis. J Autism Dev Disord. 2014 Apr;44(4):766-75.

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MoBa does... prenatal exposure to acetaminophen and offspring ADHD risk

MoBa mentioned in the title of this post refers to the Norwegian Mother and Child Cohort Study, an initiative that has figured quite a few times on this blog (see here and see here and see here for examples).

This time around [1] scientific attention turned to a question of growing research importance: does acetaminophen - paracetamol to us here in Blighty - use during pregnancy affect the risk of offspring being diagnosed with attention-deficit hyperactivity disorder (ADHD)? The data thus far on the issue of this pain-relieving, antipyretic medicine and offspring health has been discussion-provoking to say the least (see here and see here)...

The findings reported by Eivind Ystrøm and colleagues [1] are based on observations for over 100,000 offspring "including 2246 with ADHD." Both "maternal use of acetaminophen during pregnancy and... paternal use before pregnancy" were included in the statistical mix designed to estimate "hazard ratios (HRs) for an ADHD diagnosis."

The results were not exactly unexpected given what has gone on before in this area of investigation. Acetaminophen use was pretty widespread across all pregnancies; approximately 50% of mums had used it at some point. Short-term use during pregnancy - less than 8 days - actually correlated with a decreased risk of offspring ADHD according to the Ystrøm findings. More chronic use of the medicine however - "more than 29 days of maternal acetaminophen use" - showed an opposite relationship, yielding something like a 200% increase in offspring ADHD "even after adjusting for indications of use, familial risk of ADHD, and other potential confounders."

Alongside the suggestion that short-term paracetamol use was associated with a decreased risk for offspring ADHD was another 'make you think' finding: "Paternal and maternal use of acetaminophen were similarly associated with ADHD." Here, a father's use of paracetamol a month or so before conception seemed also to affect the risk for offspring ADHD too. In some media interest on this paper, the authors speculate "that "it could be that fathers who use a lot of acetaminophen have a higher genetic risk for ADHD" or that long-term use of the medicine might lead to changes in sperm." I might add that given the focus on paracetamol as a pain-relieving medicine, the topic of pain and ADHD is already something present in the peer-reviewed science domain (see here). Further research is called for in an accompanying editorial on the Ystrøm paper by Mark Wolraich [2] noting the benefits of using 'big data' from initiatives such as MoBA.

Accepting that the Ystrøm results suggest correlation and not necessarily causation, not everyone has been overwhelmed by the findings. I note in that lay media piece about the research, a few critical voices have suggested that "children diagnosed with ADHD by codes in their medical records" is no substitute for the real 'diagnostic' thing. Personally, I don't see this argument as being particularly valid as anyone that reads anything about MoBA would probably realise. Scandinavian countries and their population databases have some of the best collected and kept databases in the world in terms of reliability and applicability of population health data and statistics. A quick check on PubMed regarding the amount of peer-reviewed data that has been generated from MoBA for example, illustrates that point well.

Perhaps a more pertinent issue is the question of whether longer-term use of paracetamol during pregnancy could denote a more serious underlying maternal illness/injury which might have a more powerful effect on the risk of offspring ADHD than medicine use itself. This is a similar sort of argument to that put forward in relation to pregnancy antidepressant use and various offspring outcomes detailed in the research literature (see here) and similarly, is not something that can be answered by study designs such as those used by Ystrøm.

But then other the questions arise: 'Is paracetamol use during pregnancy safe?' 'How much is safe?' and 'What are the alternatives?' At this point I'm going to stand back and say little more given my blogging caveats of no medical and/or clinical advice given or intended. I will refer you to some current opinion on this topic provided in the peer-reviewed domain [3] alongside suggesting that more large and smaller-scale investigations are required, including that on 'adjacent' diagnoses in relation to pregnancy paracetamol use too (see here)...

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[1] Ystrøm et al. Prenatal Exposure to Acetaminophen and Risk of ADHD. Pediatrics. 2017. Oct 30.

[2] Wolraich ML. An Association Between Prenatal Acetaminophen Use and ADHD: The Benefits of Large Data Sets. Pediatrics. 2017. Oct 30.

[3] Andrade C. et al. Use of acetaminophen (paracetamol) during pregnancy and the risk of attention-deficit/hyperactivity disorder in the offspring. J Clin Psychiatry. 2016 Mar;77(3):e312-4.

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8 in 1000 babies born with foetal alcohol spectrum disorder

The results of the systematic review and meta-analysis published by Shannon Lange and colleagues [1] make for important reading with their conclusion that the global prevalence of foetal alcohol spectrum disorder (FASD) is estimated to be around 8 in 1000 live births. The accompanying editorial by Albert Chudley [2] rightly talks about 'high time for action' on the basis of such figures, particularly because FASD is a largely preventable condition and specific groups of people and specific geographical regions seem to carry elevated risk(s) when it comes to offspring FASD and so can be targeted for additional support.

Looking at the collected data from 24 studies examining the prevalence of FASD - a condition whereby babies exposed to alcohol in the womb present with specific morphological features and accompanying behavioural / cognitive issues - researchers concluded that around 7.7 per 1000 live births presented with FASD. They reported that 76 counties (of 187 countries providing data) showed an estimated prevalence rate for offspring FASD above 1% of total births. South Africa came top with over 1 in 10 births being estimated to present with FASD. Croatia, Ireland, Italy and Belarus filled the other top 5 hotspots for FASD with estimated prevalence rates between 3-5% of births derived from various methods.

'Special populations' are also mentioned in the Lange paper. Specifically: "the prevalence of FASD among special populations was 15.6 to 24.6 times higher among aboriginal populations... 5.2 to 67.7 times higher among children in care... 30.3 times higher in a correctional population... 23.7 times higher in a population with low socioeconomic status... and 18.5 times higher among a population in psychiatric care compared with the global prevalence among children and youth in the general population." One might argue that at least for some of these at-risk populations, issues such as binge drinking habits combined with an elevated risk of unplanned pregnancy [3] could lie at the root of the estimates detailed by Lange et al. I say that minus any sweeping generalisation but in light of the scientific 'facts' detailed in the latest review paper.

I note that some of the media around the Lange findings (see here) have already mentioned about some of the behavioural manifestations of FASD 'crossing over' with diagnoses such as attention-deficit hyperactivity disorder (ADHD) and autism. I would perhaps draw your attention to a previous blogging occasion when I discussed some of the research specifically looking at any overlap between autism and FASD (see here) and how one needs to be quite careful not to overplay any would-be links despite some data on possible overlap [4] (this paper was also from Lange).

Then to the specifics of the hows-and-whys of alcohol exposure in-utero causing FASD and whether effects might somehow be mitigated. Alcohol (ethanol) is a known teratogen [5] so effects are likely to be numerous in terms of how it affects the developing foetus. I note that the word 'epigenetics' has entered the vocabulary when it comes to possible mechanisms of effect(s) and that would suggest that at some point there may be ways and means of mitigating the effects of alcohol consumption at critical periods during pregnancy. At some point.

For now the message from Lange and colleagues is clear: FASD is not an uncommon finding in many different countries and different populations, and remains largely preventable. Abstinence from alcohol is advised before and during that special time (see here). And just in case anyone thinks I'm only zooming in on mums-to-be, dads might also heed similar advice at critical periods too.

Straight Edge from Minor Threat seems an appropriate song to conclude this post given what the song title means (veganism and the non-use of prescription medicines are optional extras I might add)...

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[1] Lange S. et al. Global Prevalence of Fetal Alcohol Spectrum Disorder Among Children and Youth. JAMA Pediatrics. 2017. Aug 21.

[2] Chudley AE. Fetal Alcohol Spectrum Disorder—High Rates, High Needs, High Time for Action. JAMA Pediatrics. 2017. Aug 21.

[3] Font-Ribera L. et al. Socioeconomic Inequalities in Unintended Pregnancy and Abortion Decision. Journal of Urban Health. 2008;85(1):125-135.

[4] Lange S. et al. Prevalence of Externalizing Disorders and Autism Spectrum Disorder among Children with Fetal Alcohol Spectrum Disorder: Systematic Review and Meta-analysis. Biochem Cell Biol. 2017 May 18.

[5] Randall CL. Alcohol as a teratogen: a decade of research in review. Alcohol Alcohol Suppl. 1987;1:125-32.

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Pre-pregnancy weight and risk of offspring ADHD

"Compared to normal weight mothers, the risk of having a child with ADHD [attention-deficit hyperactivity disorder] was significantly increased if the mother was overweight..., obese... or severely obese."

So said the findings reported by Andersen and colleagues [1] examining data from some 80,000 mother and child pairs "participating in the Danish National Birth Cohort (DNBC)." The name of the research game was to look-see whether maternal weight before pregnancy might be an important factor when it comes to offspring developmental and behavioural outcomes specifically with ADHD and/or autism in mind.

The results showing a possible relationship between maternal pre-pregnancy weight and ADHD were to some extent mirrored in relation to offspring autism albeit not showing the 'dose trend' of hazard ratios - overweight, obese, severely obese - noted in relation  to ADHD. Indeed authors noted that: "Regarding ASD [autism spectrum disorder], an increased risk was observed in underweight... and obese... mothers" illustrating a less confident pattern of possible association.

This is not the first time that this topic has been discussed on this blog (see here). One still has to be a little careful with such 'observational' research so as not to assume that only pre-pregnancy maternal weight is a risk factor for offspring ADHD or anything else. I'm also minded to suggest that the continued use of the body mass index (BMI) statistic is not without difficulties. That and the fact that we're also no further forward when it comes to talking about possible mechanisms behind any association given the myriad of effects that excess weight can potentially cause to mother and any children to be (see here).

What we can however take from this and other independent data [2] is that the physical health of mothers (and fathers) might be quite important to offspring even when the prospect of children is still a twinkle in the eyes of parents. We're all constantly being told to eat well, exercise regularly and cut out or cut back on certain things to achieve optimal health and wellbeing. This and other research if true, suggest that heeding such advice might have inter-generational implications too, for lots of different reasons [3]...

Music to close, and sorry Your Majesty, but some of my brood find the alternative 'God Save the Queen' much more entertaining than the original...

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[1] Andersen CH. et al. Maternal body mass index before pregnancy as a risk factor for ADHD and autism in children. Eur Child Adolesc Psychiatry. 2017 Jul 15.

[2] Van Lieshout RJ. et al. Pre-pregnancy and pregnancy obesity and neurodevelopmental outcomes in offspring: a systematic review. Obes Rev. 2011 May;12(5):e548-59.

[3] Jensen ET. et al. The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm. J Pediatrics. 2017. March 21.

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Antidepressants during pregnancy and autism in offspring (with care)

There are a few topic areas in the quite vast autism research landscape that consistently seem to keep cropping up. The possibility of some kind of *association* between pregnancy antidepressant use and risk of offspring autism is one of those areas (see here) as the results published by Dheeraj Rai and colleagues [1] (open-access) are presented for your attention. I would also draw your attention to an accompanying editorial discussing the Rai findings (see here).

So: "To help to improve the understanding of the association between antidepressant use during pregnancy and autism in offspring, we applied a range of... causal analytical methods on data from a large total population cohort in Stockholm County" was the starting point, as once again one of those very useful Scandinavian registries provided the source study material (indeed, Rai et al are seemingly experts in their analysis of such resources). The added bonus to the Rai study was their attempt to 'unravel' any association between gestational antidepressant exposure and autism from the reason why such medication was being taken in the first place: maternal psychiatric health issues (and whether this variable may in fact account, at least in part, for any association that has previously been identified).

From a starting population approaching three-quarters of a million people, researchers eventually settled on looking at over 250,000 children under 17 years of age (but over 4 years of age "in whom a diagnosis of autism might be less reliable") who were born to over 150,000 mothers. The vast majority of children (239,943 of 254,610) had no history of exposure to antidepressants during pregnancy. The remaining participants were divided up into two groups: one where there was documentation leading to the assumption of exposure to pregnancy antidepressants (n=3342) and one where there was an indication for such exposure ("mothers with a psychiatric disorder") but no recorded use of antidepressants during pregnancy (n=12,325). Researchers summed up how many children were diagnosed with an autism spectrum disorder (ASD) in each group and applied some statistical modelling.

Results: I think it's important to first highlight a statistic that seems to have been missed by many covering the Rai findings: "Of the 238 943 cohort children for whom there was no record of maternal history of psychiatric disorder or antidepressant use during pregnancy, 4889 had autism (2.1%)." That's 2.1% with a diagnosis of autism or ASD; quite a far cry from the 1% [estimate] statistic from just a few years back (at least here in Blighty).

Then: "Exposure to antidepressants during pregnancy was associated with a higher odds of a diagnosis of autism in offspring than exposure to a maternal psychiatric disorder without antidepressants." The authors caution that: "the absolute risk was small, and 4.1% of children exposed to antidepressants in utero had autism compared with 2.9% of those with a maternal history of psychiatric disorder." Further when looking at those children diagnosed with ASD in the groups, authors observed that "autism without intellectual disability" seemed to be over-represented; something also picked up in previous findings from authors on this current paper [2].

Alongside various opinions on these findings (see here for example), the authors caution about the possible meaning of their results. One obviously has to be quite careful when discussing such data to ensure that an important class of medicines is not unduly vilified. No medicine is however without potential side-effects and appropriate clinical decisions and good medicines management [2] is key, particularly when pregnancy is included as variable. The authors talk, for example, about how "if a causal link were robustly established, and if no pregnant women took antidepressants during pregnancy, only 2% of autism cases in this population would be prevented." Alongside they [importantly] mention that antidepressant use during pregnancy is not typically just a 'choice' but rather being clinically indicated: depression does not simply disappear when a woman is pregnant. Interestingly too, they mention about how their data "suggest that there is an increased background risk of autism in children of women with psychiatric conditions, regardless of antidepressant treatment." This follows a trend in other areas of psychiatry (see here for example).

Yet again, the call is further research in this area and, quite a few more investigations into the possible hows-and-whys of any association (with medication use and/or maternal psychiatric presentation) is made. I might also suggest that taking into account other childhood conditions such as attention-deficit hyperactivity disorder (ADHD), potentially over-represented when it comes to a diagnosis of autism or ASD, could be another important step forward in light of other preliminary *associations* being made with pregnancy medication history in mind (see here). This also includes looking at any issues associated with timing of potential exposure and/or dose ("Because of small numbers, we were not able to assess trimester specific or dose response effects.").

Insofar as the suggestion that autism without intellectual (learning) disability might be an important phenotype when it comes to any association, subsequent research in this area seemingly fits in well with increasingly vocal calls [4] to stop using the generic label of autism as a research starting point (see here). Allied to suggestions for more 'bottom-up' research with autism in mind (see here), also coincidentally mentioning "maternal SSRI use during pregnancy" in the context of autism [5], a future research agenda is seemingly emerging. I might also point out that certain sensitivities need to be kept in mind on the basis of suggestions that an 'environmental exposure' might, in whole or part, be *associated* with a particular type(s) of autism.

All such work - present and future - however needs to be done/presented with care, understanding and minus scaremongering, so as not to unduly alarm pregnant mothers, their families or indeed, the physicians providing their care at such a critical time...

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[1] Rai D. et al. Antidepressants during pregnancy and autism in offspring: population based cohort study. BMJ. 2017; 358: j2811.

[2] Rai D. et al. Parental depression, maternal antidepressant use during pregnancy, and risk of autism spectrum disorders: population based case-control study. BMJ. 2013 Apr 19;346:f2059.

[3] Angelotta C. & Wisner KL. Treating Depression during Pregnancy: Are We Asking the Right Questions? Birth Defects Res. 2017 Jul 17;109(12):879-887.

[4] Waterhouse L. et al. The ASD diagnosis has blocked the discovery of valid biological variation in neurodevelopmental social impairment. Autism Res. 2017 Jul;10(7):1182.

[5] Unwin LM. et al. A "bottom-up" approach to aetiological research in autism spectrum disorders. Front Hum Neurosci. 2013 Sep 19;7:606.

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