GNRH1 and pregnancy disorder: Another retrospective cohort study, including 4596 live-born babies, found no significant differences in the overall incidence of congenital malformations between the PPOS (MPA 10 mg daily), GnRH antagonist protocol or mild ovarian stimulation (AOR=1.22, 95% CI= 0.61-2.44 and AOR=1.22, 95% CI=1.38 95% CI= 0.65-2.93) (24).