Early Elective Deliveries Reached Nearly 4 Percent Before Widespread Efforts To Promote Full-Term Births

Nearly 4 percent of uncomplicated births occurred before 39 weeks and were associated with adverse outcomes, according to an AHRQ-funded study that analyzed 7.3 million births from California, Missouri and Pennsylvania from 1995 to 2009. The study period predated widespread initiatives that advocated full-term births, such as “Choosing Wisely.” Researchers found that among uncomplicated births, the average gestational age declined from 40 weeks in 1992 to 39 weeks in 2002. The rate of nonindicated early-term births peaked in 2006 at more than 4 percent of uncomplicated births. Newborns delivered before 39 weeks’ gestation were found to experience a higher incidence of respiratory distress as well as longer hospital stays. The study, “Trends in Childbirth Before 39 Weeks’ Gestation Without Medical Indication,” was funded by AHRQ and the Eunice Kennedy Shriver National Institute for Child Health and Human Development. The article and abstract were published in the July issue of Medical Care.

2014 Jul;52(7):649-57. doi: 10.1097/MLR.0000000000000153.

Trends in childbirth before 39 weeks' gestation without medical indication.

Kozhimannil KB1, Macheras M, Lorch SA.

Author information

Abstract

BACKGROUND:

There is increasing attention to labor induction and cesarean delivery occurring at 37 0/7-38 6/7 weeks' gestation (early-term) without medical indication.

OBJECTIVE:

To measure prevalence, change over time, patient characteristics, and infant outcomes associated with early-term nonindicated births.

RESEARCH DESIGN AND SUBJECTS:

Retrospective analysis using linked hospital discharge and birth certificate data for the 7,296,363 uncomplicated births (>37 0/7 wk' gestation) between 1995 and 2009 in 3 states.

MEASURES:

Early-term nonindicated birth is calculated using diagnosis codes and birth certificate records. Secondary outcomes included infant prolonged length of stay and respiratory distress.

RESULTS:

Across uncomplicated term births, the early-term nonindicated birth rate was 3.18%. After adjustment, the risk of nonindicated birth before 39 0/7 weeks was 86% higher in 2009 than in 1995 [hazard ratio (HR)=1.86; 95% confidence interval (CI), 1.81-1.90], peaking in 2006 (HR=2.03; P<0.001). Factors independently associated with higher odds included maternal age, higher education levels, private health insurance, and delivering at smaller-volume or nonteaching hospitals. Black women had higher risk of nonindicated cesarean birth (HR=1.29; 95% CI, 1.27-1.32), which was associated with greater odds of prolonged length of stay [adjusted odds ratio (AOR)=1.60; 95% CI, 1.57-1.64] and infant respiratory distress (AOR=2.44; 95% CI, 2.37-2.50) compared with births after 38 6/7 weeks. Early-term nonindicated induction was also associated with comparatively greater odds of prolonged length of stay (AOR=1.20; 95% CI, 1.17-1.23).

CONCLUSIONS:

Nearly 4% of all uncomplicated births to term infants occurred before 39 0/7 weeks' gestation without medical indication. These births were associated with adverse infant outcomes.