Progesterone therapy to decrease first-trimester spontaneous abortions in previous aborters.

A study was designed to see if the use of prophylactic progesterone vaginal suppositories (PVS) reduced the risk of spontaneous abortions in women with a history of at least one spontaneous abortion. PVS was employed during the luteal phase to the end of the first trimester. The dosage was initially 50 mg/day, but was increased according to the endometrial biopsy and doubled as soon as pregnancy was established. Only 10 women (10%) aborted, and 8 of these 10 were successful in their next PVS-treated pregnancies. Overall there were 12 losses in 132 pregnancies (9%) in these PVS-treated patients. Forty-two percent of untreated controls aborted (10/24). The results suggest that PVS is effective in reducing the risk of spontaneous abortions in high-risk patients.