Perinatal outcome of twin pregnancies obtained after in vitro fertilization: Comparison with twin pregnancies obtained spontaneously or after ovarian stimulation

Objective: To compare the perinatal outcome of IVF-ET twin pregnancies to twin pregnancies conceived spontaneously or after ovarian stimulation without IVF-ET. Design: Retrospective analysis. Patients: Three groups of patients: those who conceived after IVF-ET (n = 72), after ovarian stimulation without IVP-ET (stimulation group, n = 82), or spontaneously (spontaneous group, n = 164). Main Outcome Measures: High blood pressure, premature rupture of membrane, threatened premature labor, prematurity, low birth, small-for-gestational-age, cesarean section, and perinatal mortality. Results: Patients of the IVF-ET group were older and of higher socioeconomic class. We did not find any significant difference in the data analyzed, with the exception of the rate of emergency cesarean sections. In the IVF-ET group the prematurity rate (38.9%), small-for-gestational-age (18%), and perinatal mortality (3.47%) were not statistically different with respect to the stimulation group (45.1%, 23.2%, and 3.05%, respectively) or the spontaneous group (39.6%, 22.7%, and 4.27%, respectively). Conclusions: Twin pregnancies account for 20% to 25% of all IVF-ET pregnancies. Their risk of adverse perinatal outcome does not seem to be increased when compared with spontaneous pregnancies or to pregnancies obtained after ovarian stimulation but without IVF-ET. However, a reduction in the proportion of multiple pregnancies, including twin gestation, should be a goal for IVF-ET teams.