Background: Luteal phase support (LPS) with progesterone is a generally accepted practice after controlled ovarian stimulation, although the best protocols for LPS have been debated. We aimed to compare the efficacy of vaginal micronised progesterone tablets and 8% vaginal progesterone gel for LPS using real-world data.
Methods: This retrospective study included 459 in vitro fertilisation/intracytoplasmic sperm injection cycles performed at a university hospital from 2005 to 2019. All cycles were followed by fresh day 3 embryo transfer (ET). Either progesterone tablets or gel was used for LPS. To control the conditional probability of progesterone tablets or gel use, doubly robust inverse probability weighting composed of inverse-probability-of-treatment weighting (IPTW) and regression adjustment (RA). IPTW was performed based on the covariate balancing propensity score (CBPS).
Results: Progesterone tablets were administered in 65 cycles, and progesterone gel was administered in 394 cycles. Women who used progesterone tablets were more likely to be older (36 vs. 34 years), have primary infertility (78.5% vs. 61.4%), use gonadotropin-releasing hormone antagonist (60.0% vs. 43.2%), and have fewer retrieved oocytes (seven vs. nine) and transferred embryos (two vs. three) than participants who used progesterone gel. After IPTW-CBPS and RA analysis for the above covariates, the adjusted odds for clinical pregnancy in women who used progesterone tablets were 1.10 times compared with women who used progesterone gel; however, the 95% confidence interval did not reach statistical significance (0.96-1.26).
Conclusions: Clinical pregnancy was comparable between vaginal micronised progesterone tablets and vaginal progesterone gel for LPS in fresh day 3 ET cycles.
Keywords: Embryo transfer; fertilisation in vitro; luteal phase; progesterone; propensity score.
In vitro fertilisation (IVF) treatment helps couples who have difficulty getting pregnant by using special medications to stimulate the ovaries and produce more eggs. However, the use of these medications can sometimes cause a hormone called progesterone to become too low. Progesterone is very important for helping the early stages of pregnancy, so additional progesterone is usually given to support the treatment. The most common way to give progesterone during IVF is through the vagina, which is convenient and effective. In this study, we compared two different forms of vaginal progesterone: tablets and gel. The medical records of 459 IVF cycles from January 2005 to December 2019 were reviewed. Vaginal micronised progesterone tablets were used in 65 cycles, and vaginal progesterone gel was used in 394 cycles. To ensure fair results, we matched the two groups based on various factors that could affect the outcomes. Our results showed that the success rates of getting pregnant were similar between the two forms of progesterone. This suggests that both progesterone tablets and progesterone gel are equally effective options for supporting IVF treatment.