Increased neonatal morbidity despite pulmonary maturity for deliveries occurring before 39 weeks.

OBJECTIVE

To compare neonatal outcomes following deliveries <39 weeks after confirmation of fetal lung maturity with scheduled deliveries ≥39 weeks.

METHODS

A retrospective cohort study examining neonatal outcomes of women who were delivered following documented fetal pulmonary maturity at 36, 37, and 38 weeks compared to women undergoing a scheduled delivery at 39, 40, and 41 weeks. The χ(2)-test and Student's t-test were used to compare categorical and continuous data, respectively.

RESULTS

Delivery prior to 39 weeks following fetal pulmonary maturity was associated with a 8.4% composite neonatal morbidity rate as compared to 3.3% for deliveries at 39 weeks or greater (relative risk [RR] 2.9; confidence interval [CI] 2.4-3.6). Neonatal respiratory morbidity was significantly higher (5.4%) for those delivering at less than 39 weeks with documented fetal pulmonary maturity as compared to 2.1% for those delivering at 39 weeks or greater (RR 3.0; CI 2.3-3.9). Increased neonatal morbidity persisted for those delivered prior to 39 weeks even after excluding all diabetics (p < 0.001). Significant increases in neonatal morbidity were noted for deliveries prior to 39 weeks regardless of the mode of delivery.

CONCLUSION

Despite fetal pulmonary maturity, delivery before 39 weeks is associated with significantly increased neonatal morbidity when compared to scheduled deliveries at 39 weeks or greater.