by Justina Hurley
Study raises good questions and argues for need for more research into possible triggers for ASD and ADHD.
A new study by an Irish team of researchers at the The Irish Centre for Fetal and Neonatal Translational Research (INFANT) in University College Cork has found that delivery by Caesarean Section (C-Section) is associated with a modest increased odds of Autistic Spectrum Disorder (ASD), and possibly Attention-deficit Hyperactivity Disorder (ADHD), when compared to vaginal delivery.
Association means that something is linking the two issues here, but the full story is not clear and this is not the same as cause. This study is not saying that c-sections cause ASD or ADHD.
Unfortunately, the media reporting of this has run with an overblown and exaggerated summary of the risk and this, in our view, detracts from the relevance of this study.
What the study did find was that the association between C-section and a modest increased odds of ASD and possibly ADHD leaves room for more research into what other factors might surround this.
As the rate of Caesarean Section grows worldwide there has been increasing concern from health professionals as to what impact a Caesarean Section may have on the future health of both baby and mother.
Many Caesareans are necessary and indeed vital for both mother and baby, but there is a tendency also towards elective Caesarean, meaning women choosing to have a cesarean section rather than a natural birth.
Much is now known about gut bacteria, for example and how important it is for the baby to be exposed to the mother’s bacteria via a vaginal birth. A c-section exposes the baby to skin bacteria only and the impact of this change for the baby is an area that needs a lot more research.
Likewise, the rise in birth induction rates is worrying. Babies tend to be born when they are ready and inducing a birth can lead to a higher chance of c-section. The question here is are those last days in the womb vital for the baby’s development? Does bringing the baby out too soon, even if it is by a few days impact on the baby’s development?
And in medical emergencies or health conditions that necessitate a C-section, is it the health condition that the mother is suffering from that is having the effect rather than the c-section itself?
There are many factors behind the need for a C-section and, regardless of why, in most situations other than emergencies a C-section means that the baby is born earlier than he or she would have been than if able to go to full term via natural delivery.
Professor Louise Kenny, an Obstetrician in Cork University Maternity Hospital and one of the authors of the study, speaking on Newstalk Radio in Ireland said:
“We really want to reassure pregnant Mums as much as possible that the actual overall risk is very small indeed and furthermore we’re not entirely clear that actual mode of delivery is responsible for this association at all.
It could actually be and it’s highly likely, that it’s actually the reasons underlying the caesarean section that are driving this. For example, older Mums often have a variety of medical complications which necessitate delivery by cesarean section and we know that autism is more common in older mums so it might be nothing to do with caesarean delivery at all and that’s why we do think urgent research and further research is needed in this area.” (Source)
Both ASD and ADHD have previously been shown to be associated with risk factors that can occur during pregnancy, birth and the weeks after birth, so it is very important to look at any external factors that could trigger the onset of these conditions. The study itself concludes by saying:
“The potential cause for such disorders urgently requires further investigation. As these are disorders with a strong genetic basis (Guinchat et al., 2012; Polanska et al., 2012), clearly understanding the interrelationship between environmental factors such as mode of delivery and genetic susceptibility requires further attention. To draw more firm conclusions, future research should distinguish between emergency and elective CS and include adequate adjustment for potential confounders and effect modifiers perhaps through the use of sibling controls.”
Eileen A. Curran1,*, Sinéad M. O’Neill1,2, John F. Cryan3, Louise C. Kenny1, Timothy G. Dinan4, Ali S. Khashan1,5 and Patricia M. Kearney5
Journal of Child Psychology and Psychiatry 27 OCT 2014 DOI: 10.1111/jcpp.12351