Tim Robinson

❝For years, research has shown that babies born by cesarean section are more likely to develop health problems. Now, a groundbreaking study suggests that not all C-sections are equally risky.

The research looked at all full-term, firstborn births in Scotland over a 15-year period and tracked the babies’ long-term health. It is one of the largest and longest studies to explore how planned C-sections differ from other deliveries.

❝Surprisingly, the data showed more health problems among babies born by planned C-section than among those delivered by emergency C-section or vaginal birth, even though the planned surgery is done under more controlled conditions. The finding suggests that the arduous experience of labor — that exhausting, sweaty, utterly unpredictable yet often strangely exhilarating process — may give children a healthy start, even when it’s interrupted by a surgical birth.

❝The new findings…are important because the number of babies born by C-section has increased tremendously. In the United States, nearly one in three babies are born by C-section…

❝Dr. Mairead Black, the University of Aberdeen obstetrician who led the study, said that as cesarean births had increased in Scotland and worldwide, the researchers wondered what, if anything, children born by C-section “are missing out on.”

“Our thinking was: If a baby is born naturally, it comes into contact with bacteria from the mother, which might help with immune system development,” Dr. Black said.

Even attempted labor may provide some exposure to bacteria, she said. But babies delivered by a planned C-section, which is usually scheduled to take place well before the first pang of labor, may miss out entirely…

❝Studies have consistently found that children born by C-section are at higher risk for health problems like obesity and allergies. C-section birth has also been associated with a higher risk for Type 1 diabetes.

The Scottish study took advantage of the small country’s rich trove of linked birth and medical databases to track the long-term health of 321,287 babies. Nearly 4 percent were born by planned C-section and 17 percent were delivered by emergency surgery. The remaining 252,917 were vaginal births.

The researchers compared a range of health outcomes among the babies, including asthma, irritable bowel syndrome, obesity, Type 1 diabetes, early death and cancer…

❝No one knows exactly why labor may be protective, but the spontaneous onset of labor prompts fluid to clear from a baby’s lungs, said Dr. Aaron Caughey, who helped draw up 2014 guidelines for the American College of Obstetricians and Gynecologists that urged providers to let women spend more time in labor and avoid an unnecessary C-section…

The step is just one of a cascade of physiological changes that take place in mother and baby during the labor process, including surges in stress hormones and reproductive hormones like oxytocin that may help the fetus adapt during labor, preserve blood flow to the organs, and keep the baby alert and prepared for breast-feeding.

❝During labor, a newborn absorbs maternal microbes into its mouth and gastrointestinal tract…The theory is that maternal microbes “train” the infant’s immune system, so it doesn’t overreact or become destructive and precipitate autoimmune disorders like Type 1 diabetes…

❝Dr. Josef Neu said the broad-spectrum antibiotics prescribed to the mother before a surgical delivery were another concern; the antibiotics can be transmitted to the baby through breast milk if not before birth, decreasing the diversity of natural bacteria.

❝Childbirth and labor are “a physiological process that we’ve evolved to over millions of years,” Dr. Caughey said. “It’s been really well-designed by evolution.”

I’ll second that emotion.