孕妇应该选择剖腹产还是自然产?

With her due date approaching and her unborn son pointed feet first, Fiona Simmonds tried every technique she knew of -- acupuncture, raising her pelvis above her head and playing music near her belly -- to encourage the baby to flip around and allow him be delivered normally. But in the end, the baby remained breech and she needed a caesarean section.

Today, about a third of U.S. births are done by caesarean section, up from 21% in 1998, one of the highest of any developed country, the National Center for Health Statistics reported in March. Public-health officials are concerned about the rising rate because c-sections hold more health risks for the mother -- including possible infection and blood loss -- and are more expensive than a vaginal birth.

Medical experts say many c-sections -- which involve delivering a baby through a surgical incision -- are performed unnecessarily. But for a growing number of women, a c-section is the safer option for delivering a baby, and in some emergency cases, it might be the only choice. Medical experts say they're now seeing more medically-necessary c-sections as women have children later in life and obesity rates rise.

'We're seeing more obese women and that leads to more' caesareans because they are more likely to have other medical conditions that can lead to complications during childbirth, such as diabetes and high blood pressure, says Jacques Moritz, director of gynecology at St. Luke's-Roosevelt Hospital Center in New York.

Moms with diabetes tend to have larger babies that can get stuck in the birth canal and obesity can make it more difficult to monitor the baby during delivery. Older moms are more likely to experience complications during pregnancy such as gestational diabetes and preeclampsia (a condition characterized by high-blood pressure during pregnancy), which can boost the risk of a c-section. And the increased use of fertility treatments including in-vitro fertilization, which can result in multiple births, also can make a c-section necessary, Dr. Moritz says.

When a baby weighs more than 10 pounds, a c-section is often the safer option. Dr. Moritz also chooses a c-section when the mother has been in labor for a long period and not able to deliver. A long labor could signal that the baby is having trouble fitting through the mom's pelvis. A caesarean also is necessary for twins whose heads are not pointed down and anytime there are triplets, he says. And c-sections are often ordered when a baby's heart rate goes down during labor.

The number of c-sections performed in the U.S. each year for medical reasons isn't counted. But the World Health Organization has said that when c-sections rates go above 15% of total births, that usually indicates too many are being done.

The rise in caesarean sections hasn't resulted in fewer delivery complications or healthier moms and babies, says George A. Macones, chairman of obstetrics and gynecology at Washington University in St. Louis and a spokesman for the American College of Obstetricians and Gynecologists.

Women who deliver a baby by caesarean section face a number of medical risks, including the possibility of infection, blood loss, pulmonary embolism and death.

The risks are magnified after a first child is delivered by c-section: In subsequent pregnancies, there's an increased likelihood that the uterus could rupture. Second and third c-sections also have higher risks of excessive bleeding that could necessitate a hysterectomy.

Vaginal deliveries, of course, carry their own risks, the most common of which are pain and trauma to the pelvic floor, which can sometimes result in incontinence. But they are generally safer than c-sections, Dr. Meyer says. And there are also health benefits for babies: Passing through the birth canal helps prepare the lungs for breathing air.

But doctors say that a c-section is indicated if a normal delivery would be risky for baby or mom. When Mrs. Simmonds baby failed to move out of the breech position, she scheduled a caesarean.