528: Leukotriene receptor antagonist as a novel tocolytic in an in vitro model of human uterine contractility for preventing preterm labor

Abstract

twin pregnancies who delivered in New York City from 2003-2012. One cohort (n 532) was managed by a single maternal-fetal medicine practice and delivered at one large academic medical center. This cohort underwent routine CL screening every 2-3 weeks starting at 16 weeks and fFN screening every 2-3 weeks beginning at 22 weeks. The second cohort (n 456) were all twin pregnancies delivered at a second large academic center. The second cohort did not undergo routine CL and fFN screening and only had these tests done as clinically indicated. Outcomes measured include cerclage placement, PTB, spontaneous PTB (SPTB), and antenatal corticosteroid (ACS) exposure. RESULTS: Rates of cerclage placement, PTB, and SPTB were similar between the two groups (Table). However, routine screening using CL and fFN was associated with improved rates of ACS exposure in women who delivered 34 weeks and 34-36 6/7 weeks, without an increased ACS exposure in women who delivered at term. CONCLUSION: In twin pregnancies, routine CL and fFN screening does not reduce the risk of PTB or SPTB. However, the routine use of these tests significantly improves ACS exposure for women who deliver preterm without significantly increasing ACS exposure to women who deliver at term.