Early Initiation and Long-Term Use of Vaginal Progesterone may Cause Gestational Diabetes Mellitus.

Background: Preterm birth (PTB) is an important cause of neonatal mortality and morbidity. Spontaneous PTB (sPTB) is the most common cause of PTB. In patients with a singleton pregnancy, progesterone treatment appears to reduce the rate of spontaneous preterm birth in those with a previous history of spontaneous preterm labor and/or cervical shortening in the current pregnancy.