Should intravenous tocolysis be considered beyond 34 weeks’ gestation?

Objective: Our purpose was to assess the incidence of respiratory distress syndrome in nonindigent women with uncomplicated preterm labor between 34 and 36 weeks’ gestation. Study Design: All women seen between June 1, 1992, and April 15, 1999, with uncomplicated preterm labor and intact membranes and delivering between 34 and 36 weeks’ gestation were analyzed. Rates of respiratory distress syndrome after delivery were calculated. A χ2 analysis was performed, and a P value of < .05 was considered statistically significant. Results: Respiratory distress syndrome was noted in 8 (17.4%) of 46 infants delivered at 34 weeks’ gestation, in comparison with 5 (6.3%) of 80 infants and 7 (4.2%) of 165 infants delivered at 35 and 36 weeks’ gestation, respectively (P = .008). The rate of respiratory distress syndrome after delivery at 34 weeks was significantly higher than at 35 weeks (P = .048). Conclusion: The rate of respiratory distress syndrome after delivery at 34 weeks is significantly higher than at either 35 or 36 weeks’ gestation in our population. (Am J Obstet Gynecol 2000;183:356-60.)