Births by cesarean delivery increased to nearly one third of all deliveries in 2008, a year in which the total number of births diminished, according to the “Annual Study of Vital Statistics: 2008,” published online December 20 in the journal Pediatrics.

The study, compiled from birth and death certificates and other records, showed that the cesarean delivery rate increased in 2008 from 2007, but the total number of births, teen birth rates, and preterm deliveries each declined, while the percentage of births to unmarried women and birth rates for women older than 40 years both increased.

“The total cesarean-delivery rate rose to 32.3% in 2008, which marks the 12^th consecutive year of increase and another record high for the nation,” write T. J. Mathews, MS, from the National Center for Health Statistics, at the Centers for Disease Control and Prevention in Hyattsville, Maryland, and colleagues.

Since 1996, when cesarean deliveries made up 20.7% of all births, the annual number of cesarean deliveries has risen by 56%. In the mid-2000s, the trend slowed, but in 2008, the percentages of cesarean deliveries again increased for every age and ethnicity, by 1% for non-Hispanic whites, 2% for Hispanics and non-Hispanic blacks, and nearly 4% for Asians or Pacific Islanders.

Preliminary data show that 34.5% of non-Hispanic black women delivered by cesarean compared with 32.4% of non-Hispanic white women and 31.0% of Hispanic women. According to a 2005 report on low-risk births, non-Hispanic blacks had more cesarean deliveries even when deliveries presented little risk.

Risk factors for cesarean include diabetes, hypertension, macrosomia (overweight newborn), and labor induction, but these conditions do not justify the higher rates among non-Hispanic blacks.

Obesity can also necessitate cesarean delivery. Non-Hispanic black women have a higher rate of obesity, and women who are obese (body mass index, ≥30 kg/m²) have at least twice the number of cesarean deliveries as normal-weight patients (body mass index, <25 kg/m²). However, evidence suggests that controlling for body mass index does not alter the results.

“Other possible contributing factors that may influence the differences according to race and Hispanic origin in cesarean deliveries are maternal choice, patient education, and physician practice patterns,” the authors write. “Further study is necessary to fully understand differences in cesarean-delivery rates according to race and Hispanic origin.”

Fewer Births in Teenagers, Women Younger Than 40 Years Result in Overall Decrease

Births in the United States fell by about 2% from 2007 (n = 4,316,233, the highest ever) to 2008 (n = 4,251,095). The total fertility rate decreased from 2122.5 per 1000 women in 2007 to 2085.5 per 1000 women in 2008. Teenage birth rates, which rose between 2006 and 2007, decreased 2% in 2008.

Among the different age groups, fertility rates were as follows:

• birth rates for women aged 20 to 24 years fell 3%;
• for those women aged 25 to 29 years, rates declined 2%;
• for women aged 30 to 34 years, births dropped less than 1%;
• for those women aged 35 to 39 years, rates decreased 1% — the first decline in this age group since 1978; and
• for those aged 40 to 44 years, births rose 4%.

“The birth rate for women aged 45 to 49 years also increased in 2008, from 0.6 to 0.7,” the authors write. “This rate has more than tripled since 1990.”

The study authors have disclosed no relevant financial relationships.

Pediatrics. Published online December 20, 2010. Nancy Fowler Larson

J. Kyle Mathews, MD

Plano OBGYN Associates

Plano Urogynecology Associates

Tags: body mass index, Cesarean Deliveries, Dr. Mathews, fertility, kyle mathews, labor, little, MS, Nancy Fowler Larson, Non Hispanic, Plano Urogynecology Associates Births, Total Births, women | Category: News & Education, Obstetrics |