Dydrogesterone use in early pregnancy.

Successful oocyte implantation and a favorable pregnancy outcome rely on optimal progesterone levels. Therefore, progesterone deficiencies associated with infertility and miscarriage have commonly been treated with progestogens that mimic the activity of progesterone. Among those is dydrogesterone, an oral retrosteroid with a structure closely related to that of progesterone yet with a greater bioavailability and higher selectivity for the progesterone receptor. This review describes the efficacy of dydrogesterone for the treatment of threatened and recurrent miscarriage, and infertility due to luteal phase insufficiency. Data from clinical trials evaluating dydrogesterone in assisted reproductive technology are also discussed. Prospective clinical trials, systematic reviews and meta-analyses have demonstrated that dydrogesterone significantly improves pregnancy outcomes in women with threatened miscarriage or with a history of miscarriage. Although this is not yet a registered indication, dydrogesterone was as effective as vaginal micronized progesterone for luteal phase support in the setting of assisted reproductive technology. The safety and tolerability of dydrogesterone treatment in pregnant women are also briefly addressed and the data support a well-established and favorable benefit-risk profile.