Researchers have found despite fetal pulmonary maturity, babies delivered at between 36 to 38 weeks, still have a significantly increased risk of neonatal morbidities. The findings were presented at the Society for Maternal-Fetal Medicine’s annual meeting in San Francisco.
To compare neonatal outcomes, the team looked at mothers who had positive fetal lung maturity tests at between 36 to 38 weeks. They compared the neonatal outcomes from these scheduled deliveries prior to 39 weeks with known fetal lung maturity to the outcomes from scheduled deliveries at 39 weeks to 41 completed weeks.
The retrospective cohort study looked at data from a single institution over a 12 year period. Neonatal outcomes of women who were delivered following documented fetal pulmonary maturity at 36, 37, and 38 weeks were compared to women undergoing a scheduled delivery at 39, 40, and 41 weeks.
A lamellar body count of ≥36,000, lecitin/sphingomyelin (L/S) ratio >2.0, or a phosphotidyglycerol (PG) of 0.3 were considered mature. Neonatal outcomes examined included neonatal intensive care unit (NICU) admission, length of stay in the NICU, total neonatal respiratory morbidity, cases of respiratory distress syndrome, transient tachypnea of the newborn, other respiratory morbidity, neonates requiring mechanical ventilation, proven sepsis, hypoglycemia, and neonatal deaths. Fetuses with major congenital anomalies were excluded. Neonatal outcomes between the two groups were compared using the chi square test.
The study concluded that despite fetal pulmonary maturity, deliveries between 36 0/7 to 38 6/7 weeks are associated with significantly increased neonatal morbidity.
“Patients need to be counseled carefully if they choose to have a scheduled delivery prior to 39 weeks,” said Yu Ming Victor Fang, MD, one of the study’s authors. “Even if tests indicate that their baby’s lungs are mature, delivery prior to 39 weeks is not without risks.”
Source: Society for Maternal-Fetal Medicine