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

Abstract #73898

Marian F. MacDorman, PhD¹, Joyce A Martin, MPH², and Martha Munson, MS². (1) Statistician, National Center for Health Statistics, National Center for Health Statistics, 3311 Toledo Road, Room 7318, Hyattsville, MD 20782, 301.458.4356, mfm1@cdc.gov, (2) Division of Vital Statistics, National Center for Health Statistics, 3311 Toledo Road, Room 7318, Hyattsville, MD 20742

Despite efforts to reduce the preterm birth rate, the percent of infants born preterm has increased by 12% from 10.6% in 1990 to 11.9% in 2001. Increases in the preterm birth rate are of concern because preterm infants have higher rates of long-term disability and death than full-term infants. Preterm birth rates are higher for multiple births, and the increase in multiple births during the 1990’s – largely due to assisted reproductive technologies – has contributed to the rising preterm birth rate. Still, the preterm birth rate for singletons also rose 10% during the time period. The preterm birth rate also varies substantially according to maternal race/ethnicity, age and smoking status, with higher rates for black and Puerto Rican mothers, teen and older (aged 35+) mothers, and smokers. The percent of births to older mothers increased from 1990-2001, however, the percent of births to teenagers, and to smokers declined; thus these last two factors cannot explain the increase in the preterm birth rate. A little-studied studied area of preterm birth research concerns the effect of changes in medical practice on preterm birth rates. From 1990-2001, the percent of preterm births with induced labor more than doubled (from 6.7% to 13.7%), while the percent delivered by cesarean section increased by 23% (from 28.7% to 35.4%). Major factors influencing the preterm birth rate are discussed in light of recent changes in medical practices.

Learning Objectives:

At the close of the session participants will be able to:
• Recognize the risk factors for preterm birth.
• Describe the effect of medical interventions on preterm birth.
• Describe the March of Dimes plan to address risk identification and risk reduction for preterm birth.

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.