THE OUTCOME OF TWIN PREGNANCIES AFTER IVF

dIt has been suggested that the high rates of prematurity, low birth w eight, perinatal morbidity and mortality in in-vitro fertilization (IV F) infants are due to the increased frequency of multiple gestations i n this population. The aim of our study was to test this hypothesis by comparing the outcome of IVF twins with that of twins born after spon taneously conceived pregnancies. The perinatal outcome of 40 IVF twins was compared with that of 80 control twins, matched for maternal age, parity and ethnic origin. IVF twins had a higher rate of prematurity (P = 0.03), their mean birth weight was significantly lower (P < 0.01) and the frequency of very low birth weight infants was much higher (P < 0.003). There was no neonatal mortality in the control group, where as four IVF twins died (P < 0.01). Neonatal morbidity was significantl y greater in IVF twins (P < 0.05). Oxygen therapy and mechanical venti lation were administered more frequently to IVF twins (P < 0.007 and P < 0.05). We conclude that twins conceived by IVF are at a significant ly higher risk for prematurity and associated neonatal morbidity and m ortality than spontaneously conceived twins.