LOS ANGELES, CA (Catholic Online) - According to the National Institutes of Health, such deliveries probably are performed before women are in active labor. In addition, an increasing proportion of first-time mothers are delivering by C-section, while fewer women who have had a previous C-section deliver subsequent babies vaginally.

In 2007, the most recent year for which final data are available, a record 31.8% of births were by C-section. Preliminary data showed that the 2008 rate inched up even further, to 32.3%.

Authors of the study collected information from electronic medical records for 228,668 deliveries that occurred from 2002 through 2007 at 19 U.S. hospitals. The authors of the study found that the overall C-section rate for the deliveries was 30.5%.

About 44% of women who attempted a vaginal delivery were induced, and they were twice as likely to deliver by C-section as women who went into labor on their own. Because the study wasn't of women who had been randomly assigned to be induced or wait for spontaneous labor, it can't prove that induction itself is to blame for the higher C-section rate. Perhaps some other characteristic of the women who were induced made them more likely to have a C-section, he said.

Nearly half of the C-sections in women who were induced and in women with a previous C-section were performed before their cervix was dilated 6 centimeters. The cervix is fully dilated at 10 centimeters. Active labor is typically thought to begin when the dilation reaches 4 centimeters, but a recent study showed that women who've previously given birth might not start the active phase until 6 centimeters, according to the study.