(The New York Times News Service) -- Inducing labor has become increasingly popular over the past two decades, despite concerns from many doctors that the practice made women more likely to end up having a cesarean section.

Now, a study by Bay Area researchers released Monday suggests that women who choose to induce labor may actually be at less risk of a C-section. What's important is that doctors and their patients give the induction a chance to work before they choose surgery over a vaginal birth, said Dr. Aaron Caughey, a University of California at San Francisco obstetrician and author of the study.

"Instead of thinking globally that (induction) is bad, or something I'm willing to use even if I know it causes C-sections, we want people to realize that it's not the induction itself, it's how it's managed," Caughey said. "Patience is really a virtue in this setting."

The researchers, who published their findings in the Annals of Internal Medicine, analyzed 11 randomized, controlled studies and 25 observational studies. Those earlier studies primarily looked at women who were induced when they were at least one week past their due date. The authors noted that more research should be done on women who induce labor between 39 weeks and 41 weeks of pregnancy.

More than 22 percent of pregnant women in the United States end up inducing labor, more than twice the rate in 1990, when 9.5 percent of births involved inducing labor. According to the researchers' analysis, women who chose to induce labor had a 20 percent lower rate of C-sections than women who simply waited to give birth.

Inducing labor has few major side effects for most women, but doctors long perceived labor induction as leading to a greater risk of C-section. In fact, that may be true in some busy hospitals where doctors can't afford to wait too long for a woman to begin active labor, or a woman doesn't want to wait several days for the induction to work.

If doctors want to avoid C-sections, they have to be prepared to send a woman home and give the induction time to work, said Douglas Owens, a senior investigator with the Veterans Affairs Palo Alto Health Care System and a professor at Stanford University School of Medicine.

"On both sides, with the women and the physicians, they might be eager for labor to happen at a certain time," said Owens, also an author of the study. "But it doesn't necessarily work that way."

Labor can be induced by a variety of medical processes, including drugs or devices used to manually dilate the cervix.

Doctors will induce labor if it's safer for the mother or fetus to deliver the baby sooner rather than later. But they might also induce labor for "elective" reasons, which could include concern over developing complications if a woman is past her due date.

Women and their doctors may also choose to induce labor for scheduling purposes -- if the doctor is going out of town or even if parents prefer to have their baby on a weekend. Caughey said he's had several parents ask to induce labor so they could avoid having a baby on Sept. 11.

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