In the past, doctors thought that once a woman had a C-section, she would need to do the same for any future births -- mainly out of concern that the scar on the uterus would rupture during vaginal delivery.

That thinking has changed, though.

In fact, experts say a vaginal delivery has advantages for women who've had a past C-section. Moms have a shorter hospital stay and recovery time. And vaginal delivery is less likely to cause certain complications, like excessive bleeding and infection.

But the new study shows that women may not be aware of those facts when they choose between a repeat C-section or what doctors call a "trial of labor."

Researchers found that of women who'd opted for a repeat C-section, almost three-quarters did not know what the actual risk of uterine rupture would be with a trial of labor.

That risk is low -- about a 0.5 percent to one percent chance, on average.

Most women were also unaware that C-section carries a relatively higher risk of breathing problems for newborns and a higher risk of death for mothers.

Fortunately, serious complications are rare, regardless of what type of delivery you choose, said Dr. Sarah N. Bernstein, who led the study.

"The point of this is not to say that one option is better than the other," said Bernstein, who was based at St. Luke's-Roosevelt Hospital Center in New York when she worked on the study.

"They are both safe options," said Bernstein, who is now at Magee-Womens Hospital in Pittsburgh.

Still, women should make their decision based on as much information as possible, Bernstein and her colleagues say.

The findings, reported in the American Journal of Obstetrics & Gynecology, are based on a survey of 155 women with a prior C-section who were all candidates for a trial of labor. The survey included multiple-choice questions on the risks associated with the two types of delivery.

Overall, 87 of the women had already opted to try vaginal delivery, while 68 had chosen a repeat C-section. Women in both groups had a tough time answering some of the survey questions.

For example, it's estimated that a trial of labor is successful between 60 percent and 80 percent of the time ("Success" means that the doctor does not have to change course in the middle of labor and do a C-section).

But only four percent of women having a repeat C-section chose the correct success rate from a list of options, and most (73 percent) did not even hazard a guess about what the correct answer was.

Of women having a trial of labor, only 13 percent picked the correct success rate answer; 54 percent said they didn't know.

And only 40 percent of women opting for a repeat C-section knew that the procedure comes with a longer recovery time.

It's well known that many countries have high C-section rates. In the U.S., C-sections now account for one-third of all deliveries. That's an all-time high, and one that experts generally agree is too high.

The reasons are various. The rising rate of multiple births has played a role, since those babies may have to be delivered by C-section. A desire to schedule childbirth for a day of the mother's choosing is another common reason given for C-sections in recent years.

But repeat C-sections account for a large share of the U.S. total. And experts say that doing more trials of labor would trim the national C-section rate.

Still, many U.S. hospitals do not even offer women the option of a trial of labor because they cannot guarantee a team on hand to perform an emergency C-section if necessary.

Bernstein said there are many factors that affect the choice between repeat C-section and a trial of labor -- including doctors' biases and worry over malpractice.

And no one knows whether women's knowledge is a big factor in the high C-section rates in the U.S. and elsewhere.

Bernstein pointed to a study in Australia, in which researchers found that giving women an "information aid" boosted their knowledge of the pros and cons of repeat C-sections and trials of labor. But it did not lower the number of women opting for a repeat C-section.

For any individual woman, the key is to ask questions, according to Bernstein.

"Have a really good discussion of your options with your OB," she said. "Don't just read about it online or listen to your friends."

Every woman is different, Bernstein noted, and the benefits and risks will vary. As an example, she said that the reason for your first C-section is important.

If you had a C-section because the baby was not in the normal head-down position, your chances of a successful vaginal delivery next time are high. The odds of success are lower if the C-section was done because your cervix was not dilating enough during labor.

SOURCE: bit.ly/MKibDg American Journal of Obstetrics & Gynecology, online June 13, 2012.

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