The interval to spontaneous delivery following discontinuation of maintenance tocolysis.

OBJECTIVE: To determine the interval to spontaneous delivery following discontinuation of continuous subcutaneous terbutaline (SQT). METHODS: Singleton and twin gestations receiving outpatient preterm labor management services with SQT were identified from a database. Patients having SQT discontinued at 33.0-35.9 weeks (in a stable condition, not hospitalized and with known cervical status at discontinuation) with subsequent spontaneous labor and delivery were included (n = 1420). Data were compared by gestation type, week of SQT discontinuation and cervical dilatation using Kruskal-Wallis and Fisher's exact test analyses (p < 0.05 statistically significant). RESULTS: Spontaneous preterm delivery occurred in 63.0% of singletons and 87.9% of twins. Although stable at SQT discontinuation, 32.5% of singletons and 59.9% of twins delivered within three days. The interval from discontinuation of SQT to delivery was less for twin than singleton gestations (5.1 +/- 6.5 vs. 11.0 +/- 10.5 days, respectively, p < 0.001). CONCLUSIONS. Preterm discontinuation of SQT should be avoided if additional pregnancy prolongation is desired.