Lung risks. Having a planned C-section two or three weeks before the due date is particularly risky, even though babies born at that point are considered to be full term. In December, researchers reported in the British Medical Journal that babies delivered by elective C-section three weeks before the due date, compared with same-age babies delivered vaginally or by emergency C-section, had four times the risk of breathing complications and five times the risk of serious lung problems because of immature lung development. The risks were lower but still elevated among those born two weeks early. Although doctors are supposed to wait until 39 weeks—a week before the due date—to perform a planned C-section, all too frequently they do the surgery earlier for convenience or because of an incorrect estimation of the due date.
Going through the process of labor, regardless of how a baby is delivered, may confer benefits as well, says study leader Anne Kirkeby Hansen, a research fellow at Aarhus University Hospital in Denmark. "Certain stress hormones are released right before and during labor that are very important for lung maturity."
There's no question that some women need C-sections, such as those with placenta previa. But the World Health Organization recommends a cap of 15 percent of deliveries—the U.S. rate in 1978—based on evidence showing that higher levels don't benefit either mother or baby. Though the drama-free planned C-section certainly has its appeal, Declercq stresses that women and doctors need to "stop seeing it as just another surgery."