Vaginal micronized progesterone versus intramuscular progesterone for luteal support in women undergoing in vitro fertilization-embryo transfer.

OBJECTIVE: To study the outcome of IVF-ET in women who used vaginal P (vaginal P(4)) versus those who used P in oil via IM injection (IM-P(4)) for luteal support.
DESIGN: Retrospective cohort.
SETTING: Tertiary referral infertility center. PATIENT(S): A cohort of 544 women. INTERVENTION(S): In 145 women, vaginal P(4) was used, while in 399 women, IM-P(4) was used for luteal support. MAIN OUTCOME MEASURE(S): The primary outcome was ongoing pregnancy rate. Secondary outcomes included other IVF-ET outcomes: rates of clinical pregnancy and pregnancy loss (chemical and miscarriage) and serum P levels during the luteal phase and early pregnancy. RESULT(S): Women who used vaginal P(4) for luteal support had ongoing pregnancy rates (odds ratio [OR], 1.0675; 95% confidence interval [CI], 0.7587-1.5020) and rates of total pregnancy loss (OR, 1.0775; 95% CI, 0.7383-1.5727) that were not statistically different from those who used IM-P(4). During the luteal phase, women who used vaginal P(4) had mean serum P levels that were not statistically different from those who used IM-P(4). However, during early pregnancy, mean P levels in pregnant women who used vaginal P(4) were statistically significantly higher. CONCLUSION(S): In women undergoing IVF-ET according to the GnRH agonist long protocol, luteal support with vaginal P(4) was associated with treatment outcomes that were no different from those associated with IM-P(4) luteal support. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.