In earlier posts I discussed how studies on rats have revealed that early life experiences modify the epigenome, which has long term consequences for stress responsiveness, reproductive behaviors, and obesity rates. It’s often difficult to do epigenetic studies on humans due to ethical concerns, but some pretty clever work has been done lately revealing that the results from the rat studies may be broadly applicable.
I found this article recently that describes a study comparing the methylation patterns of children delivered naturally to children delivered by C-section. They found that the section of the epigenome which codes for white blood cells is more heavily methylated in children born by C-section, perhaps because this procedure is more stressful for the child than natural birth.
We already know that children delivered by C-section are at a greater risk for diabetes, allergies and leukemia and the researchers who ran this study postulate that these greater risks may be the result of changes in methylation patterns during delivery.
It’s unclear whether the methylation patterns is caused by the procedure per se or by the mother’s stress over whatever complications are resulting in the need for a C-section in the first place. Further studies will be needed, but (as I mentioned in a previous post) some studies have already concluded that the fetus’ epigenome is altered when mothers are stressed out or depressed during gestation.
If researchers can convincingly make the claim that C-sections change methylation patterns (and therefore patterns of gene expression) in babies and that these changes in gene expression result in a greater risk for particular diseases, then perhaps we’ll see the trends in C-section rates reverse. At the moment, the percentage of deliveries that are done by C-section is steadily increasing worldwide.
I was under the impression that most C-sections were done when there were complications that put the mother and/or the baby at risk, but it looks like there are plenty of less serious reasons for why women get this procedure done. Some mothers elect to have C-sections so that they can “maintain vaginal tone” (i.e., they don’t want to become “loose”) or because they don’t want to experience the pain associated with childbirth. Doctors are also inclined to perform C-sections at the slightest hint of a complication because this could save them from dealing with expensive malpractice suits.
I’d be interested in seeing if differences in the prevalence of particular diseases between countries could be correlated with country specific C-section rates. For example, Brazil has the highest rate of C-section delivery and I would be interested in finding out if they also have high rates of diabetes, allergies and leukemia as well.
Hopefully clever research will teach us more about the link between C-section, the epigenome and the risk of contracting particular diseases. If a clear link is found then we may see a big change in the way the public perceives non-emergency C-sections.