Trial of Progesterone in Twins and Triplets to Prevent Preterm Birth (STTARS)

Women pregnant with twins or triplets are at high risk of preterm birth, yet no intervention or approach has served to reduce this risk. A recently completed trial by the NICHD sponsored Maternal Fetal Medicine Units (MFMU) Network has, for the first time, demonstrated a treatment that substantially reduces the rate of preterm birth in women at high risk for preterm delivery (i.e. progesterone therapy). Preterm birth was reduced by 35% among progesterone-treated women with a singleton pregnancy when compared with women receiving placebo. The current trial compares weekly treatment by injection of progesterone with placebo in women pregnant with twins or triplets.