Exploring a Possible Link Between C-Sections and Autism

A 2018 editorial in the British medical journal The Lancet titled “Stemming the global cesarean section epidemic” estimated that 6.2 million unnecessary cesareans are done every year, half of them in Brazil and China.

Everyone agrees that some cesarean births are absolutely essential, for the health of the mother, the safety of the baby, or both. And Dr. Caughey said that for an individual woman, a cesarean “shouldn’t feel like a crushing defeat.”

He suggested that pregnant women should talk through labor and delivery with their health care providers, certainly by the time they are in the second trimester. “By and large, most providers in this country are not looking to do more cesarean sections,” he said.

Thirty years ago, Dr. Betran said, “We weren’t even thinking of these other long-term effects, asthma, obesity.” Instead, those concerned with high cesarean rates were looking only at the mortality rates of mothers and infants and other short-term risks. Though cesarean rates of 10 percent or 15 percent meant significant drops in mortality, rates much higher than those do not necessarily save many more lives, though they might benefit children in other ways.

Looking at increasing cesarean rates around the world, Dr. Betran said, “there is no single cause for the increase.” Societies are changing in many different ways that can affect how babies are born. She was the lead author on a 2018 article in The Lancet that reviewed possible interventions, from supporting midwives and providing companionship in labor to reducing the financial incentives for cesarean birth and addressing concerns about litigation. Still, the article acknowledges that bringing down these rates has been challenging.

If you need a cesarean, you should have a cesarean: “It saves lives when used for medical indications,” Dr. Betran said. But in a world — or a country — where cesarean rates can vary so widely, we need to be thoughtful about how the operation is deployed, since there is no advantage to cesarean birth when those medical indications are not present, she said, “and it may influence the life of the mother and the child” in many ways, as these studies suggest, and perhaps in other ways which we haven’t yet imagined or investigated.

Many people who have children with neurodevelopmental issues (and other health issues) worry over causation, questioning genetic links, environmental exposures, pregnancy and birth history, and a long list of other possibilities. That’s why this kind of research — and the research that should follow from it — is so important. Such research can help tease out some of the underlying differences among the children, and begin to elucidate mechanisms, from the microbiome on, by which the details of a baby’s journey into the world can shape that baby’s life to come.

And let me say again, or let the author of the study say it: “Association doesn’t mean causation; we can’t say cesarean section is causing this,” Ms. Zhang said. “We did find the association, which means further studies are needed.” However, she said, “Women shouldn’t be hesitant about cesarean sections when they are medically indicated.”