Effect of adjunctive vaginal progesterone after McDonald cerclage on the rate of second-trimester abortion in singleton pregnancy: a randomized controlled trial.

OBJECTIVE: To evaluate the effect of adjunctive use of vaginal progesterone after McDonald cerclage on the rate of second-trimester abortion in singleton pregnancy. METHODS: A randomized controlled trial at Woman's Health Hospital, Assiut University, Egypt, between April 2017 and March 2019 enrolled women eligible for McDonald cerclage. After cerclage, participants were randomly assigned to receive progesterone (400 mg pessary) once daily until 37 weeks or no progesterone. The primary outcome was rate of abortion before 28 weeks. Secondary outcomes included gestational age at delivery, preterm delivery, mean birthweight, Apgar score, and admission to the neonatal intensive care unit (NICU). RESULTS: The rate of spontaneous abortion was higher in the no-progesterone group (P=0.016). Mean gestational age and mean birthweight was higher in the progesterone group (P<0.001 and P=0.002, respectively). The frequency of preterm neonates, neonates with Apgar score less than 7, and admission to NICU was higher in the progesterone group than in the no-progesterone group (P=0.005, P=0.008, and P=0.044, respectively). CONCLUSION: Adjunctive use of vaginal progesterone after McDonald cerclage was found to decrease the frequency of second-trimester abortion and to improve perinatal outcomes in singleton pregnancy.