Progesterone is a sex hormone that is essential for the maintenance of pregnancy. However, taking progesterone supplements during the first 12 weeks of pregnancy does little to help women with a history of unexplained, recurrent miscarriages.

Share on Pinterest The trial found that taking progesterone in the first trimester did not help women with unexplained, recurrent miscarriages avoid another loss.

This was the conclusion of a 5-year trial led by the University of Birmingham in the UK and published in the New England Journal of Medicine.

The findings of the PROMISE (progesterone in miscarriage treatment) trial – conducted in 45 hospitals in the UK and the Netherlands – settle 60 years of uncertainty about whether progesterone is an effective treatment for preventing miscarriage in women with a history of unexplained, recurrent losses.

The randomized, double-blind, placebo-controlled trial included 826 women of average age 33 years with previously unexplained recurrent miscarriage. They received twice-daily vaginal suppositories of either progesterone or matched placebo for up to 12 weeks of gestation.

After analyzing the results, the authors conclude that:

“Progesterone therapy in the first trimester of pregnancy did not result in a significantly higher rate of live births among women with a history of unexplained recurrent miscarriages.”

This was true regardless of age, ethnicity, medical history and pregnancy history, they note.

Nearly two thirds of the participants carried to full term and had their babies, with no significant difference between the treatment group (65.8% live birth rate) and the placebo group (63.3% live birth rate).