Difference in outcome of twins between early and delayed referrals

Data on the prognosis of twins from tertiary institutions may not represent the general incidence of adverse infant outcomes. We retrospectively investigated the infant outcome in 32 twin gestations referred to us at 29.9 +/- 3.7 weeks of gestation (range, 21 to 38 weeks) (late referral group) and 237 twin gestations that had been monitored by us since < 20 weeks' gestation (control group). The physical and neurological status of infants was assessed at 1 year of corrected age. Delivery occurred 3.1 weeks earlier in the late referral group than in the control group (32.4 +/- 3.9 vs 35.5 +/- 2.4 weeks, p < 0.001). Deaths by 1 year of age and disabilities such as cerebral palsy, mental retardation, and epilepsy occurred in 16 (25%) of 64 infants in the late referral group compared with 24 (5.1%) of 474 infants in the control group (p < 0.001). Thus, the inclusion of data on women who were referred late increased the incidence of adverse infant outcomes in our tertiary hospital from 5.1% to 7.4% (40/538). It was not known whether an early referral to a tertiary hospital would have improved the outcome in the late referral group. These findings suggest that data from tertiary institutions on the prognosis of twins may be affected adversely by the inclusion of data on women who are referred because of complications.