The 131st Annual Meeting (November 15-19, 2003) of APHA

Abstract #61342

Michael J. Davidoff, MPH¹, Joann Petrini, PhD, MPH¹, Rebecca Russell, MSPH¹, Karla Damus, RN, PhD¹, and Nancy Green, MD². (1) Perinatal Data Center, March of Dimes Birth Defects Foundation, 1275 Mamaroneck Ave, White Plains, NY 10605, 914.994.4549, mdavidoff@marchofdimes.com, (2) March of Dimes, 1275 Mamaroneck Ave, White Plains, NY 10605

Increasing US c-section rates have been attributed to many factors including the rise in multiples and births to women 35+, and may contribute to the increasing preterm birth rate (<37 weeks gestation). Using natality data from NCHS, this study addresses trends and disparities in c-section rates among infants >20 weeks by maternal race/ethnicity for preterm (20-36 weeks) and not preterm (>37 weeks) births.

Over the past decade, the US c-section rate among births >20 weeks decreased from 22.6% in 1991, to a low of 20.7% in 1996, then increased to 22.9% in 2000. Between 1991-1996, the c-section rate among non-Hispanic black infants (NHB) remained unchanged at nearly 22%, while the rate among non-Hispanic white infants (NHW) decreased 10.7% (23.3% to 20.8%). Between 1996-2000 this trend reversed, increasing by 11.5% among NHB (21.8% to 24.3%) and 11.1% among NHW (20.8% to 23.1%).

Between 1996-2000, c-section rates among preterm deliveries increased 16.1% for NHB, compared to 10.6% for NHW, but among not preterm infants the change was almost equal for NHB and NHW (~10.5%). In 2000, c-section rates for preterm births were highest for NHW (36.4%), however, the rate for not preterm infants was highest for NHB (22.9%). Between 1996-2000, the RR (preterm/not preterm) of having a c-section for NHB increased from 1.29 to 1.35, whereas the RR for NHW (1.69) remained the same.

While c-section rates among preterm infants are increasing most rapidly for NHB, rates are still lower than NHW. Analyses stratifying by maternal age and plurality will be presented.

Learning Objectives:

• Describe national trends in total, primary, and repeat c-section rates by maternal race/ethnicity, plurality, and maternal age.
• Within demographic groups, understand the risk of having a c-section for preterm and not preterm infants, and identify how this risk is changing.

Keywords: Pregnancy Outcomes,

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.