The most telling finding of a new study on cesarean sections in hospitals in the United States is that 31.2 percent of first-time mothers had C-sections.

"Reducing primary cesarean delivery is the key" to bringing down the overall C-section rate, the researchers concluded. In 2007, the last year studied, America's C-section rate stood at 32 percent, a new high.

The study, an analysis of nearly 229,000 births at 19 hospitals between 2002 and 2008 published on-line ahead of a print article in the American Journal of Obstetrics and Gynecology, was conducted under the aegis of the National Institute of Child Health and Human Development.

The study found that 44 percent of women attempting a vaginal delivery were induced. Half of the women who had C-sections for dystocia — slow or difficult labor — were cervically dilated to less than 6 cm, far short of the 10 cm dilation that signals that birth is imminent, when the decision was made to operate.

Of the 29 percent of women in the study who had previous C-sections, and were allowed a trial of labor, 57 percent delivered vaginally.

The overall cesarean rate was 30.5 percent.

The abstract of the study concludes, "To decrease cesarean delivery rate in the United States, reducing primary cesarean delivery is the key. Increasing vaginal birth after previous cesarean rate (sic) is urgently needed. Cesarean section for dystocia should be avoided before the active phase is established, particularly in nulliparous women and in induced labor."

Many of the births included in the study took place at teaching hospitals, where more complicated birth often land, the study's authors noted.