Which progesterone supplement method is most effective?

This study compared the effectiveness of oral and vaginal progesterone supplementation in women undergoing in vitro fertilization.

The hormone progesterone is important for the successful implantation and development of an embryo. It is often recommended that women undergoing assisted reproductive techniques use progesterone supplements to increase the likelihood of successful implantation and pregnancy.

There are different methods of administration for progesterone, including vaginal suppositories and oral supplements. Oral supplementation is often the preferred method for patients, but progesterone administered orally must be metabolized by the liver, which may decrease the effectiveness. A newer oral progesterone supplement, dydrogesterone (Duphaston), retains its effectiveness through metabolism, and has been associated with a 31% pregnancy rate following in vitro fertilization, with few side effects for the woman or the fetus. However, recent studies have had conflicting results as to whether dydrogesterone was as effective as vaginal supplementation. The current study directly compares oral supplementation with dydrogesterone and vaginal supplementation in women undergoing in vitro fertilization (IVF).

This prospective study followed 80 women undergoing IVF for male infertility. Women were randomly assigned to either oral progesterone supplementation with dydrogesterone (40 mg daily)or vaginal supplementation with Cyclogest (800 mg daily). Progesterone supplementation continued through the 12th week of pregnancy. A clinical pregnancy was considered as a viable fetus at 6 weeks (a heartbeat could be measured with ultrasound).

Clinical pregnancy rates were 25% in the dydrogesterone group and 32.5% in the vaginal supplement groups, and were not significantly different. Miscarriage rates were also equal between the two groups, at 7.5% for those taking dydrogesterone and 7.7% for those in the vaginal supplement group. Bleeding was experienced by 48% of women in the dydrogesterone group and 20% of the vaginal supplement group, while nausea was experienced by 25% of the dydrogesterone group and none of the women receiving vaginal supplementation. Epigastric pain (pain in the upper abdomen) was experienced by 15% of the dydrogesterone group and none of the women receiving vaginal supplementation.

This study concluded that oral progesterone supplementation with dydrogesterone was as effective as vaginal supplementation, though with higher rates of adverse effects.