OUTCOME OF TWIN GESTATIONS WITH A SINGLE ANOMALOUS FETUS

OBJECTIVE: Our goal was to determine whether the presence of one anoma lous fetus in a twin gestation affects pregnancy outcome when compared with twin pregnancies without fetal anomalies. STUDY DESIGN: Maternal and neonatal data from 970 twin pregnancies delivered from 1988 to 19 95 were collected. Three groups of twin gestations were identified: on e fetus with a major anomaly (n =18), one fetus with a minor anomaly ( n = 38), and both fetuses without anomalies (n = 914). RESULTS: Matern al demographic characteristics (age, race, and antepartum complication s) were similar among the groups. There was no difference in neonatal outcome (gestational age at delivery, birth weight, cord pH, sepsis, a nd death) in the minor anomaly and no anomaly groups. There were signi ficant differences between the major anomaly group and the no anomaly group in gestational age at delivery (32.9 vs 35.6 weeks, p < 0.05), b irth weight at delivery (1759 vs 2291 gm, p < 0.05), hospital days (41 vs 13 days, p < 0.05), and perinatal death of the anomalous fetus (27 8/1000 vs 10/1000). Except for total days in the hospital, there was n o difference in neonatal morbidity or mortality for the normal fetus w hen compared with the minor group or the no anomaly group. CONCLUSION: The presence of a fetus with a major anomaly in a twin gestation incr eases the risk of preterm delivery. The neonatal outcome of the nonano malous fetus does not appear to be affected by the anomalous fetus.