The impact of down-regulation on obstetrics and perinatal outcomes in singleton pregnancies after IVF: a retrospective cohort study

Background: Down-regulation has been widely used in IVF treatment; however, it lacks reports on the impact of down-regulation on obstetrics and perinatal outcomes. The purpose of this study is to evaluate the effect of down-regulation on obstetrics and perinatal outcomes. Methods This is a retrospective cohort study on 3578 patients achieving singleton pregnancy after their first IVF attempt. The patients were grouped by the serum estradiol after down-regulation (E2D) into three groups: 55pg/ml. The cumulative live-birth rate, obstetrics and pediatric results were main outcome measures. General linear models and Chi-square test were performed for statistical analysis. Results The patients with E2D 55pg/ml had similar cumulative live-birth rate. The patients with E2D <30pg/ml had a lower risk for hypertension disorders than those with E2D 30-55pg/ml. No difference was found in the prevalence of placenta previa, placenta abruption, premature rupture of membrane, hemorrhage, gestational diabetes mellitus, or intrauterine growth restriction. The newborns of patients with E2D 55pg/ml. There was no difference in congenital anomaly or mortality rate. Conclusion We found no effect of down-regulation on cumulative live-birth rate. The patients with E2D<30pg/ml may have advantages in lower risks for maternal hypertension and newborns PICU attempt.