A new study published in the International Journal of Fertility and Sterility found that among women with low progesterone levels, IM injection of 50 mg progesterone dramatically boosts the success rate of in vitro fertilization (IVF).
Long recognized for its critical role in the early stages of pregnancy, exogenous progesterone therapy was found to be able to prevent abortions caused by the removal of the corpus luteum before the seventh week of pregnancy, according to a series of elegant studies conducted in the early 1970s. Also, the antiprogesterone medication mifepristone works well to induce abortions in the first few weeks of pregnancy. Therefore, progesterone has long been the interest of scientists, who have concentrated on its therapeutic uses in the field of assisted reproductive technology (ART) as well as infertility therapy generally. Further studies show that, on the day of embryo transfer (ET), a low progesterone level dramatically lowers the likelihood of getting pregnant. Thus, Mahbod Ebrahimi and team wanted to determine how adding 50 mg of intramuscular progesterone per day to an 800 mg progesterone suppository might affect the success rate of IVF in women with low progesterone levels.

Infertile women who were candidates for IVF and had progesterone levels less than 9.2 ng/ml on the ET day were included in this concurrent open-label clinical study. These women were assigned randomly to either the intervention group or control group. In addition to 400 mg of progesterone suppository every 12 hours starting on the day of ET, the intervention group was provided 50 mg of progesterone intramuscularly once daily. Just 400 mg of progesterone suppositories were given to the control group every 12 hours. These medications were taken up until 12 weeks following the ET in the case of pregnancy.
There was a significant difference (P=0.035) between the number of women who had clinical pregnancy which was around 54 (50.0%) in the intervention group and 39 (36.8%) in the control group. There was a significant difference (P=0.042) in the number of women who had ongoing pregnancy in the intervention group (47, 43.5%) and the control group (33, 31.1%). The incidence of multiple pregnancies and abortions did not significantly differ between the two groups. The intramuscular administration of 50 mg progesterone considerably boosts the clinical and continuing pregnancy rates. Overall, this study suggests that IM injection of 50 mg progesterone increases the clinical and ongoing pregnancy outcomes.

Reference:
Ebrahimi, M., Akbari Asbagh, F., Davari Tanha, F., Amirkhanloo, F., Sahraiyan, G., Feizabad, E., & Lotfi, S. (2024). The Effect of Adding Daily 50 mg Intramuscular Progesterone to 800 mg Progesterone Suppository on The In Vitro Fertilization Success Rate in Women with Low Progesterone Levels: A Clinical Trial Study. International Journal of Fertility and Sterility, 18(Suppl 1). https://doi.org/10.22074/ijfs.2023.2008438.1506