Prophylactic progesterone and preterm birth

This review summarises the present knowledge of prophylactic progesterone and preterm birth. Preterm birth (< 37 weeks) is a leading cause of neonatal mortality and morbidity worldwide. The incidence varies globally but remains low in the Nordic countries (5-6%). Prediction and prevention are complicated due to diverse aetiology, but obstetric history and cervical length can improve prediction. Prophylactic vaginal progesterone initiated between 12 and 24 weeks of gestation is recommended to reduce preterm birth < 33-35 weeks in singleton pregnancies with a history of preterm birth or with a short cervix (< 25 mm) and can be considered for twin pregnancies with the same risk factors.