The association of elective cessation of tocolysis and preterm birth in singleton gestations

We evaluated outcomes following tocolysis discontinuation in singleton pregnancies between 33.0 and 36.9 weeks' gestation. We performed a retrospective analysis of singleton pregnancies prescribed continuous subcutaneous terbutaline tocolysis. Patients without indicated preterm delivery discontinuing treatment between 33.0 and 36.9 weeks were evaluated ( N = 4253). Data were grouped by week at treatment discontinuation. Outcomes were compared for each week. Approximately 55% (2316/4253) delivered preterm (< 37 weeks). After treatment discontinuation, 58.1% (2472/4253) of patients delivered within 7 days and 41.2% (1752/4253) within 3 days. Median number of days from discontinuation to delivery was 5 (range, 0 to 65). Incidence of low birth weight (< or = 2500 g), neonatal intensive care unit admissions, days in nursery, and estimated charges decreased with each additional week of tocolysis (all P < 0.05, adjusted for multiple comparisons). Tocolysis discontinuation prior to term is associated with late-preterm birth, adverse neonatal outcomes, and increased estimated health care costs.