Impact of prior gestational age at preterm delivery on effectiveness of 17-alpha-hydroxyprogesterone caproate in practice.

OBJECTIVE: We sought to examine if 17-alpha-hydroxyprogesterone caproate (17OHPC) effectiveness is dependent on the earliest gestational age (GA) at prior spontaneous preterm birth (SPTB) when administered in the clinical setting. STUDY DESIGN: Women enrolled for outpatient services with current singleton gestation and > or =1 prior SPTB between 20-36.9 weeks were identified. Data were divided into 3 groups according to earliest GA of prior SPTB (20-27.9, 28-33.9, and 34-36.9 weeks). We compared GA at delivery of current pregnancy and incidence of recurrent SPTB between women enrolled in outpatient 17OHPC administration program (n = 2978) and women receiving other outpatient services without 17OHPC (n = 1260). RESULTS: Rates of recurrent SPTB for those with and without 17OHPC prophylaxis, respectively, according to GA at earliest SPTB were: 20-27.9 weeks at earliest SPTB, 32.2% vs 40.7%, P = .025; 28-33.9 weeks at earliest SPTB, 34.1% vs 45.5%, P < .001; and 34-36.9 weeks at earliest SPTB, 29.3% vs 38.8%, P < .001. CONCLUSION: 17OHPC given to prevent recurrent SPTB is effective regardless of GA at earliest SPTB.

Antepartum uterine contraction patterns in twin pregnancies with and without preterm labor and delivering before or after 36 weeks.

OBJECTIVE: The purpose of this study was to identify differences in antepartum uterine contraction frequency (UCF) in twin pregnancies with and without preterm labor (PTL). STUDY DESIGN: Twin gestations enrolled for outpatient surveillance with twice daily electronic uterine activity monitoring and telephonic nursing assessment, without interventional delivery were identified. Mean UCF for each gestational week was compared between women without PTL or preterm delivery (PTD) < 36 weeks (controls) and those with a PTL diagnosis delivering at < 36 weeks (PTL/PTD group), and those with PTL with delivery > or = 36 weeks (PTL/GAD > or = 36 group). RESULTS: Data from 7891 patients with 267,840 monitored hours were analyzed. UCF at each gestational week was significantly higher for patients experiencing PTL with or without PTD compared to control. UCF was similar for patients with PTL with or without PTD < 36. CONCLUSION: Twin pregnancies complicated with PTL have a higher UCF than those that do not experience PTL. Outpatient surveillance may be beneficial in this population.