Antenatal Azithromycin to Prevent Preterm Birth in Pregnant women with Vaginal Cerclage. A Randomized Clinical Trial

Objective: To assess whether antenatal azithromycin given to pregnant women with vaginal cerclage can reduce preterm birth or not.
Study design: We randomized 50 women who underwent cerclage at Ain Shams University Maternity Hospital into Group A (receiving 500 mg Azithromycin oral tablets (Zithrokan®, Hikma, Egypt) one tablet orally twice daily for three days in 3 courses at 14th, 24th and 32nd week, in addition to routine antenatal care ) and an identical group B ( receiving usual antenatal care ). Our primary outcome was gestational age at delivery, while secondary outcomes were birth weight, mode of delivery, maternal and perinatal complications. This study was registered on ClinicalTrials.gov with number: NCT04278937.
Results: Gestational age at delivery was significantly higher in Azithromycin group ( 36.8weeks vs 34.1weeks; P=0.017 ). Also, birthweight was significantly higher in Azithromycin group ( 2932.6gm vs 2401.8gm; P=0.006 ). There was no significant difference between the two groups as regards other outcomes ( miscarriage, stillbirth, neonatal intensive care unit admission, antepartum hemorrhage, postpartum pyrexia, need for blood transfusion ).
Conclusion: Adding azithromycin as antenatal prophylaxis in women undergoing cerclage prolongs pregnancy and reduces risk of preterm birth, with slight increase in birthweight.