Search method to identify studies

Searches were performed in PubMed and Cochrane Register from inception of each database to 17 September 2019 using the words ‘micronized progesterone’, ‘micronised progesterone’ and ‘oral’. All records (n = 295 for ‘micronized progesterone’ and ‘oral’; n = 29 for ‘micronised progesterone’ and ‘oral’) were examined to identify relevant articles for inclusion. Systematic reviews identified in searches were reviewed for additional studies. No restrictions were applied for language or geographical location. The searches identified 17 studies of oral NMP and three studies of NMP-SR in the obstetric indications of interest. Depending on study methodology (e.g. randomised controlled trial [RCT], observational study), oral NMP or NMP-SR were investigated alone or were compared with no treatment, placebo, other progesterone formulations (vaginal, IM) or oral dydrogesterone. The results are tabulated and are reported narratively per obstetric indication.