Objective: To determine survival and morbidity in twin transfusion syndrome presenting with polyhydramnios / oligohydramnios(poly/oli) sequence managed by amnioreduction.

Study Method: Maternal and infant charts were reviewed by a combination of retrospective and prospective analysis. Perinatal survival was defined as live-birth and survival up to seven days.

Results: Between Jan. 1993 and Dec. 1996, 1 triplet and 26 twin pregnancies (N=55 fetuses) presented fitting standard ultrasound criteria of poly/oli sequence. 39 of 54 fetuses survived to delivery (1 fetus continues in utero). Of 15 fetal deaths, 12 were in 6 twin pairs all less than 28 weeks, 3 were single fetal deaths between 25 and 31 weeks. Mean gestation at delivery was 32 weeks gestation (range 22-38), 33% delivered at or before 30 weeks. Of 6 neonatal deaths, 4 of 6 were due to asphyxia, 2 of 6 were due to extreme prematurity, no deaths occurred after four days of life. 2 surviving infants required transfusion for symptomatic anemia shortly after birth, 1 required partial exchange transfusion for polycythemia. Fetal echocardiography (N=43) identified cardiac dysfunction in 11 poly fetuses. Perinatal survival for this group was 3 of 11 with 7 fetal deaths and 1 neonatal death. 2 of 3 survivors with in utero cardiac dysfunction required inotropic support within the first hours of life.

Conclusions: Our overall survival of 34 of 55 fetuses (62%) is in keeping with other series in the literature. Premature delivery remains the major morbidity despite amnio-reduction. Asphyxia is the major factor contributing to neonatal death. Fetal echocardiography may be an effective means of monitoring fetal well being in this population.