Failure of the emergency contraceptive levonorgestrel and the risk of adverse effects in pregnancy and on fetal development: an observational cohort study.

OBJECTIVE: To determine pregnancy and neonatal outcome after the failure of levonorgestrel as an emergency contraceptive.
DESIGN: A retrospective observational cohort study.
SETTING: Telephone consultations concerning reproductive risk factors conducted by Telefono Rosso-Teratology Information Service, Catholic University of Sacred Heart, Rome, Italy. PATIENT(S): Women exposed to levonorgestrel (36 cases) compared with a control group (80 cases). INTERVENTION(S): Teratological counseling. MAIN OUTCOME MEASURE(S): The rate of congenital anomalies, the prepartum or peripartum complications, and the pregnancy outcomes. RESULT(S): Twenty-five exposed newborns with length and weight identical to that of the control group were shown to be without increased risk of congenital malformation. No statistical differences were observed in terms of spontaneous or legal abortion and pregnancy and neonatal complications, and there was no ectopic pregnancy in either group. CONCLUSION(S): Although the sample size was small, in our experience, the failure of levonorgestrel as an emergency contraceptive was not associated with an increased risk of major congenital malformations, prepartum or peripartum complications, or an adverse pregnancy outcome.