Twin Gestations with a Single Anomalous Fetus / 대한산부인과학회잡지

ABSTRACT

OBJECTIVE: To evaluate of the perinatal outcome of twin gestations complicated by a single anomalous fetus. METHODS: The study included all patients with twin gestations diagnosed with a major fetal anomaly in one fetus in the second trimester during 1997-2000. Twins with anomalies in both fetuses and minor anomalies were excluded. From a total of 717 twin deliveries, there were 24 twin pregnancies with single anomalous fetus observed in Department of Obstetrics and Gynecology, CHA Hospital. Outcomes assessed included gestational age at diagnosis and delivery, antenatal complications, type of anomalies and perinatal mortality rate. RESULTS: The incidence of single anomalous fetus with twin pregnancies was 3.3% in the study population. There were 24 twin pregnancies with one anomalous fetus, and their median gestational age at delivery was 35+3 weeks (range 27-39). The incidence of preterm delivery was 54.2% (13/24) and growth restriction and respiratory distress syndrome of the normal sibling were 12.5% (8/24) and 8.3% (2/24), respectively. Eight cases (33.3%) of preterm deliveries, 3 cases (12.5%) of severe preeclampsia were noted and 2 cases (8.3%) of the pregnancies were complicated with both conditions. Regarding the type of anomalies, chromosomal anomalies and central nervous system (CNS) anomalies were the most common with 5 cases (20.8%) each. Perinatal outcomes of the normal twin and the anomalous twin were compared. There were 2 cases (8.3%) of neonatal death in the normal twin compared with 9 cases (37.5%) of intrauterine death, 9 cases (37.5%) of neonatal death in the abnormal twin. CONCLUSION: Our study shows that the presence of a major anomaly in one fetus in a twin gestation significantly increased the risk of preterm delivery and risk of intrauterine fetal death and neonatal death rate in anomalous fetus. This information may provide useful information for counseling patients about their options when faced in dilemma.