A comparison of the outcomes between twin and reduced twin pregnancies produced through assisted reproduction

ObjectiveTo compare the outcome of twin pregnancies, derived from IVF cycles, with and without fetal reduction.DesignA retrospective cohort study.SettingThe IVF Division of the Lee Women’s Hospital, Taiwan.Patient(s)Seven hundred forty-two twin pregnancies, including 389 nonreduced pregnancies, 353 of which resulted from fetal reduction.Intervention(s)Selective fetal reduction for high-order multiple pregnancies.Main Outcome Measure(s)The rates of extreme prematurity and prematurity (i.e., less than 28 and 36 weeks gestational age, respectively), frequency of birth weight discordance, mean birth weight of twins, neonatal mortality, and morbidity.Result(s)The fetal reduction group was associated with a higher incidence of extreme prematurity, prematurity, and lower birth weight than the nonreduced group, although the impact was relatively small. These findings were more pronounced among patients with a higher initial number of fetuses. The rates of discordant birth weights between the two groups were not significantly different.Conclusion(s)High-order multiple pregnancies after fetal reduction is still associated with a mild increased risk of premature delivery and low birth weight when compared to nonreduced twin pregnancies. These results provide an additional reason to limit the number of embryos transferred during IVF.