Frequency and significance of preterm delivery in twin pregnancies

Objective: We investigated the frequency of preterm delivery and its influe nce on the neonatal outcome in twin pregnancies at a perinatal center. Are there differences in the course of twin pregnancies with preterm or term de livery? Method: A retrospective investigation was carried out at the Depart ment of Obstetrics on 502 twin pregnancies and deliveries between 1978 and 1993. Pregnancy history and clinical parameters were compared among preterm (< 37 + 0 weeks) and term deliveries. Result: Median duration of all twin pregnancies was 36 + 3 weeks of gestation. In the preterm group, preterm la bor was more frequent, both, the first and the second neonate had lower bir th weight and were more often admitted to the neonatal intensive care unit (NICU) where they stayed longer than full-term neonates needing intensive c are. Perinatal deaths occurred only in the preterm group. Conclusions: The incidence of preterm delivery is significantly elevated in twin pregnancies and consequently the incidence of low- and very-low-birth-weight-infants a nd perinatal mortality. Preterm delivery is the main reason why twin pregna ncies are at a higher risk for an adverse neonatal outcome and thereby caus e considerable costs. (C) 2000 International Federation of Gynecology and O bstetrics.