Early, Elective Caesarean Sections Lead to Greater Health Risk for Newborns

January 8, 2009

A new study confirms what women’s health advocates have been saying for some time: early elective caesarean surgeries scheduled before 39 weeks of pregnancy can be harmful to a baby’s health.

The study found that newborns delivered at 37 weeks to mothers who previously had an elective c-section were up to four times more likely to have respiratory problems, require mechanical ventilation, have newborn sepsis (a severe bacterial infection) or hypoglycemia, to require admission to a neonatal ICU or to spend five or more days in the hospital after birth. Babies delivered at 38 weeks experienced twice the risk for these health problems.

“I think that as a patient or a physician, you might be convinced that being close to 39 weeks is probably good enough and there’s probably no difference if you are going to turn 39 weeks on a Sunday to have a Caesarean on, say, a Friday,” Catherine Y. Spong of the National Institute of Child Health and Human Development, which sponsored the study, told the Washington Post. “Before this, we didn’t have the data to say that there would be more risk.”

The study appears in the Jan. 8 issue of The New England Journal of Medicine. The lead author is Alan T.N. Tita, M.D., of the University of Alabama at Birmingham.  The study analyzed data on pregnancies at 19 academic medical centers across the United States that are part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development’s Maternal-Fetal Medicine Units Network.

The researchers found that of the 24,077 women who gave birth through a repeat c-section between 1999 and 2002, more than half — 13,258 — were elective; that is, there was no medical evidence indicating that the baby or mother was in distress. Close to 36 percent of the elective repeat c-sections occurred prior to 39 weeks, while 49 percent were performed at 39 weeks.

“To have more than a third of them done before 39 weeks is surprising,” Spong said. “These are all elective repeat Caesareans without a medical indication and without labor.”

The American College of Obstetricians and Gynecologists recommends that elective c-sections be done at 39 weeks or later unless there is an urgent need.

The study also looked at babies delivered at 41 and 42 weeks and found a similarly elevated risk. Yet this applies to a very small percentage of newborns in the study since it is rare for a baby to be delivered this late.

“What we found is there’s a very tiny window between 39 and 40 weeks where baby outcomes are optimal, and any deviation before or after that 39th week results in increased risk,” said John Thorp, M.D., study co-author and division director for women’s primary healthcare in the obstetrics and gynecology department at University of North Carolina Chapel Hill School of Medicine.

About one in three mothers gives birth via c-section, a rate that has skyrocketed in recent years. Meanwhile, the infant mortality rate has decreased; the United States currently ranks 29th in the world. Some researchers see a connection.

According to a New York Times story last year: “Preterm birth is a significant risk factor for infant death. From 2000 to 2005, the percentage of preterm births in the United States jumped 9 percent, to 12.7 percent of all births. The most rapid increase has been among late preterm births, or babies born at 34 to 36 weeks of gestation. Some 92 percent of these increased premature births are by Caesarean section, according to a recent study.”

It’s become commonplace to blame pregnant women for the rise in c-sections, with many articles making it sound like women are doing it to avoid labor or just for convenience (hmmm … I’ll get my hair done Saturday and then give birth!). The focus is often on class and choices made by wealthy white women, despite the fact that African American women over age 35 have the highest caesarean rate in the United States.

The Washington Post continues this trend, noting that “some women opt to deliver a little earlier for a variety of reasons, including being eager to see their baby, being tired of pregnancy or for convenience.”

It makes for a good tale, but research indicates that maternal request is not driving the increase. As Our Bodies Ourselves Executive Director Judy Norsigian wrote in a Boston Globe op-ed on the c-section rate, the increase is caused primarily by changes in obstetrical practice.

“The world of obstetrics has changed considerably since the days when a single obstetrician handled a caseload of women to whom he or she made an extraordinary commitment — to be at her birth no matter when that woman went into labor. Now, the overwhelming majority of obstetrical practices are group-based, substantially reducing that individual bond with a mother,” wrote Norsigian and her co-writer, Gene Declercq, a professor of maternal and child health at the Boston University School of Public Health.

“Another factor is the increasing concern about malpractice and the reality of lawsuits that may be brought even in instances when an obstetrician is not really to blame for a bad outcome. It is not surprising that in the gray area of clinical decision-making during labor, many obstetricians have substantially lowered the threshold for when they would perform a caesarean.”

To learn more, check out this excellent analysis from Childbirth Connection.

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