May 9, 2006 (Washington) -- Contrary to what many believe, patient requests are probably not the main driving force behind the increasing rates of cesarean births in the U.S., doctors say.
Rather, obesity is probably to blame for much of the rise, says Frederic Frigoletto Jr., MD, professor of obstetrics and gynecology at Harvard Medical School in Boston.
The doctors acknowledge that some pregnant women ask their doctors for C-sections because of the increased convenience of choosing the time of delivery and because of a desire for less painful childbirth.
A National Institutes of Health task force found some increase in patients' requests. "But it certainly didn't account for the sharp increase in cesarean deliveries," says Mary D'Alton, MD, chairwoman of obstetrics and gynecology at Columbia University Medical Center in New York.
Frigoletto says his research suggests that the increase in cesarean deliveries coincides with the epidemic of obesity in this country.
The experts discussed the rising C-section rates at a news conference at the annual meeting of the American College of Obstetricians and Gynecologists (ACOG).
C-Sections at All-Time High
By 2004, the number of C-sections had reached an all-time high, accounting for 29% of all births -- or 1 million babies -- according to the latest data from the National Center for Health Statistics.
That's in contrast to a 5% rate after World War II, a number that remained relatively stable until it skyrocketed to 15% in the 1970s.
C-sections continued to gain popularity until the early 1990s, by which time 22% of babies were delivered by cesarean.
Then reports that women who had undergone a first cesarean delivery might not need a cesarean the next time around led the rate to fall back to below 20%.
But this was soon proven false "with studies in the mid-1990s indicating that attempts for a vaginal delivery after a cesarean was dangerous for the mother," says Stanley Zinberg, MD, deputy executive vice president of ACOG. And so the number rose again.
While ACOG has no formal position on maternal-requested C-sections, D'Alton says that elective procedures should not be performed before 39 weeks of gestation unless there is a medical reason to do so.
D'Alton also stresses that women should not have more than three or four cesarean births. Repeated C-sections increase the risk of dangerous placental abnormalities in later pregnancies, she explains. More first-time cesareans are now increasing the rate of repeat surgeries later, each of which carries progressively higher risks to both mother and newborn.
Doctors are seeing more severe life-threatening complications in which the placenta fails to detach from the uterus because it sticks to scars from previous cesareans in women who have had previous cesarean deliveries, she says.
According to Zinberg, younger women are at less risk of C-section-associated complications.