C-sections at all-time high in new CDC report

The rate of births that ended in Caesarean-sections climbed by 53% in the years between 1996 to 2007, when they stood at 32%, the highest rate ever reported in the United States, the National Center for Health Statistics reported on Tuesday.

The rate is higher than those most other industrialized countries are experiencing, according to the report from the NCHS , which is an arm of the Centers for Disease Control, based in Atlanta, Ga. The cost of a C-section is almost double that of a vaginal delivery, the report notes.

C-sections were up for all groups across the board in the 11 years that were the major focus of the study, in terms of age, race, location, and how far along women were in their pregnancies.

About 1.4 million women gave birth by Ceasarean in 2007. In 2006, Caesarean delivery was the surgical procedure most often performed in American hospitals.

Here are the major findings of the report:

The U.S. C-section rate, 21 percent in 1996, was 32 percent in 2007, an increase of 53 percent. The steepest rise occurred between 2000 and 2007.

C-section rates went up by 50 percent or more in 34 states. In six states -- Colorado, Connecticut, Florida, Nevada, Rhode Island, and Washington -- the rate increased by more than 70 percent.

The rate rose for women of all age groups, with women under 25 having greatest rate of increase, 57 percent.

All racial and ethnic groups experienced increases. Black women had the highest C-section rate in 2007, 34 percent. Native American women had the lowest rate, 28 percent.

Caesarean rates increased for deliveries of infants of all gestational ages. C-sections for pre-term babies (less than 34 weeks gestational age) increased 36 percent; the rates for late pre-term babies (34 to 36 weeks) and term and post-term babies (37+ weeks) went up nearly 50 percent.

Early and late pre-term babies were more likely to be delivered by Caesarean section than were babies born at 37+ weeks.

The report cited possible reasons for the increases in Caesarean sections, in addition to medical indications for the surgery, as "maternal demographic characteristics," like advanced maternal age, fears of malpractice suits among physicians, doctors' preferences, and maternal preferences.

A medical detective story

One of the studies presented at the annual meeting of the Society of Maternal Fetal Medicine last week was an intriguing medical detective story.

Researchers at the University of Washington in Seattle noticed that their state had a high incidence of a devastating birth defect called gastroschisis, in which organs, especially the intestines, develop outside the abdomen. The defect has a 90 percent survival rate but requires extensive interventions at and after birth.

The incidence of gastroschisis has doubled and in some places quadrupled in the past 30 years, according to the study. The researchers -- Sarah Waller, Kathleen Paul, Suzanne Peterson, and Jane Hitti, all MDs -- wondered if it might have an environmental cause.

A Washington farm

Rural areas in Washington were the hardest hit

Using the state's birth-certificate data base, they determined that the highest incidence of gastroschisis was in the agricultural eastern part of the state.  They matched cases of the defect with a history of agricultural spraying provided by the U. S. Geological Survey. Three possible culprits emerged -- atrazine, nitrates, and 2,4-dichlorophenoxyacetic acid, chemicals commonly used in agriculture.

The researchers looked at all 805 babies born with gastroschisis in Washington between 1987 and 2006 (with a control group of 3,616), and then they calculated how close the babies' mothers lived to water sources with high levels of the three chemicals.

An association between gastroschisis and atrazine, a common herbicide, emerged in the study. The closer mothers lived to a water source with high levels of atrazine, the more likely they were to have a baby with gastroschisis.

The researchers also found that the incidence of gastroschisis increased with babies conceived in the spring, when spraying is especially prevalent. No association was found with the two other chemicals.

This elegant study will be the basis of more study, no doubt, the first steps down the road toward protecting babies from a possible environmental hazard.