Outcome of twin-twin transfusion diagnosed before 28 weeks of gestation.

To develop prognostic indicators for those patients diagnosed with twin-twin transfusion before 28 weeks' gestation, we conducted a retrospective analysis of all cases diagnosed at Baylor College of Medicine from January 1985 through April 1989. Twenty-seven cases of twin-twin transfusion were diagnosed by ultrasound; the criteria for diagnosis were polyhydramnios in one amniotic cavity and oligohydramnios in the other cavity. The mean (+/- SD) age at diagnosis was 21.9 +/- 2.9 weeks and the mean age at delivery was 26.8 +/- 4.9 weeks. Gestational age at diagnosis was similar in survivors and non-survivors (21.7 +/- 3.7 versus 22.2 +/- 2.8 weeks; P = .35); however, surviving infants were delivered later in gestation (31.9 +/- 3.5 versus 25.9 +/- 3.4 weeks; P = .000008). The overall survival rate was 21%. Fetal hydrops correlated with poor survival. Amniocentesis for decompression and tocolysis failed to decrease perinatal mortality.