Antenatal steroid use and neonatal outcome: United States 2007

Antenatal steroid use has been associated with reduction in the risk of neonatal mortality in meta-analyses of clinical trials. In 2007, a revised US birth certificate offered information on antenatal steroid use in 22 states. The aim of this study was to review the association between antenatal steroid use and neonatal mortality by gestational age categories for preterm infants (<37 weeks) for the United States for the year 2007.

Data were obtained from the United States Linked Infant Birth and Death Certificate Public Use Period file for the year 2007. Associations between antenatal steroid use and neonatal death were determined by logistic regression adjusting for potentially confounding variables.

There were 245 453 preterm births and 4220 neonatal deaths available for analysis with complete data on antenatal steroid use. The highest prevalence for antenatal steroid use among neonatal intensive care unit admissions (NICU) was 22% in the 26 to 28 week gestational age category, whereas the lowest prevalence was in the 34- to 36-week group at 7%. Following adjustment for potentially confounding variables by logistic regression, the adjusted odds ratios (95% confidence interval) for neonatal mortality (antenatal steroid use versus non-use) ranged from 0.56 (0.46 to 0.67) at 22 to 25 weeks; 0.66 (0.53 to 0.83) at 26 to 28 weeks; 0.69 (0.55 to 0.85) at 29 to 33 weeks and 0.69 (0.47 to 1.01) at 34 to 36 weeks.

These data are in accordance with meta-analytical data of randomized clinical trials and network reports on reduction of neonatal mortality with the use of antenatal steroids, and provide support for the use of antenatal steroids for late preterm births.