The number of women having primary cesarean sections without any apparent medical risk grew significantly during the 1990s and topped 80,000 in 2001, according to a new analysis of U.S. birth certificate data.
First-time C-sections in women with “no indicated risk” rose 67% between 1991 and 2001, from approximately 3.3% to 5.5%. The increase was gradual until 1996 and rapid toward the end of the study period. Increases were seen across all ages and parities.
Eugene Declercq, Ph.D., and his associates studied birth certificate data on approximately 4 million births per year between 1991 and 2001.
They looked specifically at women who had singleton, full-term, vertex-presentation births, without any medical risk factors or complications of labor or delivery listed on the birth certificate. They then focused on women who had a first-time cesarean.
The investigators declined to call these deliveries “elective” and instead used the term “no indicated risk” cesareans.
“Birth certificate data provide no record of the mother's intent,” said Dr. Declercq, professor in the maternal and child health department at Boston University, and his associates (BMJ [Epub ahead of print] Nov. 19, 2004. Article DOI number: 10.1136/bmj.38279.705336. Available from www.bmj.com
Age was a major factor in the rate of no-indicated-risk cesareans, they said. First-time mothers over 40 were five times more likely to have the procedure than were primiparous mothers aged 20-24.
Of multiparous women over 34 years of age who had previous vaginal births, more than 5% had a no-indicated-risk cesarean in 2001.
No-risk, primary cesareans were performed in a similar proportion—almost 5%- of women under 30 (all parities) in 2001; this represented growth of almost 60% since 1991.
All told, there were 80,028 no-indicated-risk primary C-sections performed in 2001—an increase of more than 25,000 since 1996. This represented approximately 26% of the total increase in primary cesareans between 1996 and 2001.