Why are women having nonindicated early deliveries?

Despite the increasing volume of evidence that infants born before 39 weeks can have complications, a new study shows that nearly 4% of uncomplicated births are induced before 39 0/7 weeks without a medial indication.

Researchers at the University of Minnesota performed a retrospective analysis of 7,296,363 uncomplicated births (>37 0/7 weeks’ gestation) in 3 states between 1995 and 2009. Nonindicated early term births were found by comparing diagnosis codes and birth certificate records. Infant prolonged length of stay, determined by hospital discharge records, and respiratory distress were some of the secondary outcomes.

The early-term nonindicated birth rate for the studied period was 3.18% among uncomplicated term births. Risk of nonindicated birth before 39 0/7 weeks was 86% higher in 2009 after adjustment than in 1995 (hazard ratio [HR]=1.86; 95% confidence interval [CI], 1.81–1.90), with the peak being 2006 (HR=2.03; P<0.001). Independently associated factors included the mother’s age, private health insurance, delivery at a smaller-volume or non-teaching hospital, and higher levels of education. In particular, black women had a higher risk of cesarean delivery that was not medically indicated (HR=1.29; 95% CI, 1.27–1.32). That, in turn, was associated with greater odds of a prolonged length of stay (adjusted odds ratio [AOR] =1.60; 95% CI, 1.57–1.64) and infant respiratory distress (AOR=1.20; 95% CI, 1.17–1.23) compared with births after 38 6/7 weeks. Comparatively greater odds or prolonged length of stay (AOR=1.20; 95% CI, 1.17-1.23) also were associated with early-term nonindicated induction.

The investigators concluded that nearly 4% of all uncomplicated deliveries of term infants that occur before the 39-week mark happen in the absence of medical indication. Far from being benign, these births were associated with adverse infant outcomes.

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