Perinatal outcomes of spontaneous twins compared with twins conceived through intracytoplasmic sperm injection

OBJECTIVE: To compare perinatal outcomes in spontaneous twins compared with those conceived by intracytoplasmic sperm injection (ICSI). DESIGN: Retrospective case-control study. PATIENTS: Cases consisted of 274 intracytoplasmic sperm injection twins, controls were 348 naturally conceived twins delivered between 1999 and 2003 in a tertiary hospital. MAIN OUTCOME MEASURES: Birth weight, gestational age at birth, cesarean delivery rate, perinatal mortality and morbidity, congenital anomalies, gestational diabetes and pregnancy induced hypertension. RESULTS: Preterm deliveries (76.6% vs. 64.1% <37 weeks and 19.7% vs. 13.2% <32 weeks) and low birth weight (73% vs. 60.3% <2500 g and 19.7% vs. 12.6% <1500 g) were significantly higher in the ICSI group compared with controls. Gestational diabetes mellitus (8% vs. 2.9%) and cesarean deliveries (95.2% vs. 77.6%) were more common in cases compared with the control group. There was a significantly higher rate of perinatal morbidity (16.4% vs. 7.8%) and mortality (8% vs. 2.6%) in ICSI twins. The incidence of congenital malformations diagnosed at birth was higher in cases (4.4%) compared with controls (0.9%) but the difference was not significant when adjusted for maternal age. CONCLUSION: Perinatal outcomes of twins after ICSI treatment are less optimal than naturally conceived twins.