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" target="_blank" title="ad.正常情况下；通常">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 normaldelivery would be risky for baby or mom. When Mrs. Simmonds baby failed to move out of the breech position, she scheduled a caesarean.

Jilian Mincer

• pointed [´pɔintid] a.尖(锐)的；中肯的 (初中英语单词)
• encourage [in´kʌridʒ] vt.鼓励；怂勇；促进 (初中英语单词)
• expensive [ik´spensiv] a.费钱的，昂贵的 (初中英语单词)
• involve [in´vɔlv] vt.卷缠；包括；使专注 (初中英语单词)
• medical [´medikəl] a.医学的；医疗的 (初中英语单词)
• pressure [´preʃə] n.压榨 vt.对...施压力 (初中英语单词)
• director [di´rektə] n.指导者；....长；导演 (初中英语单词)
• monitor [´mɔnitə] n.班长 v.监控；检查 (初中英语单词)
• anytime [´enitaim] ad.无论什么时候 (初中英语单词)
• possibility [,pɔsə´biliti] n.可能(性)；希望；前途 (初中英语单词)
• normal [´nɔ:məl] a.正规的 n.正常状态 (初中英语单词)
• concerned [kən´sə:nd] a.有关的；担心的 (高中英语单词)
• infection [in´fekʃən] n.感染，影响 (高中英语单词)
• emergency [i´mə:dʒənsi] n.事变；紧急关头 (高中英语单词)
• seeing [si:iŋ] see的现在分词 n.视觉 (高中英语单词)
• delivery [di´livəri] n.送交；分娩；交货 (高中英语单词)
• subsequent [´sʌbsikwənt] a.其次的；其后的 (高中英语单词)
• excessive [ik´sesiv] a.过分的；极端的 (高中英语单词)
• statistics [stə´tistiks] n.统计学；统计 (英语四级单词)
• necessitate [ni´sesiteit] vt.使成为必要；迫使 (英语四级单词)
• unborn [,ʌn´bɔ:n] a.未生的；将来的 (英语六级单词)
• technique [tek´ni:k] n.技术；技巧；方法 (英语六级单词)
• normally [´nɔ:məli] ad.正常情况下；通常 (英语六级单词)
• fertility [fə:´tiliti] n.肥沃；多产；繁殖力 (英语六级单词)
• fitting [´fitiŋ] a.适当的 n.试衣 (英语六级单词)
• spokesman [´spəuksmən] n.发言人 (英语六级单词)
• likelihood [´laiklihud] n.可能，相似性 (英语六级单词)