Luteal start vaginal micronized progesterone improves pregnancy success in women with recurrent pregnancy loss

Objective: To assess the effectiveness of luteal start vaginal micronized P in a recurrent pregnancy loss (RPL) cohort. Design: Observational cohort study using prospectively collected data. Setting: Not applicable. Patient(s): Women seen between 2004 and 2012 with a history of two or more unexplained pregnancy losses <10 weeks in size; endometrial biopsy (EB) performed 9-11 days after LH surge; and one or more subsequent pregnancy(ies). Women were excluded if concomitant findings, such as endometritis, maturation delay, or glandular-stromal dyssynchrony, were identified on EB. Intervention(s): Vaginal micronized P was prescribed at a dose of 100-200 mg every 12 hours starting 3 days after LH surge (luteal start) if glandular epithelial nuclear cyclin E (nCyclinE) expression was elevated (>200/0) in endometrial glands or empirically despite normal nCyclinE (<200/). Women with normal nCyclinE (<200/) who did not receive P were used as controls. Main Outcome Measure(s): Pregnancy success was an ongoing pregnancy > 10 weeks in size. Result(s): One hundred sixteen women met the inclusion criteria, of whom 51% (n = 59) had elevated nCyclinE and 490/o (n = 57) had normal nCyclinE. Pregnancy success in the 59 women with elevated nCyclinE significantly improved after intervention: 60/o (16/255) in prior pregnancies versus 690/0 (57/83) in subsequent pregnancies. Pregnancy success in subsequent pregnancies was higher in women prescribed vaginal micronized P compared with controls: 68% (86/126) versus 51% (19/37); odds ratio = 2.1 (95% confidence interval, 1.0-4.4). Conclusion(s): In this study, we found that the use of luteal start vaginal micronized P was associated with improved pregnancy success in a strictly defined cohort of women with RPL. (C) 2016 by American Society for Reproductive Medicine.)