Monochorionic twin pregnancy: retrospective analysis of predicted pregnancy outcome

To assess the accurate establishment of chorionicity, perinatal complications, and outcome of monochorionic twin pregnancies managed in a tertiary referral center in Croatia and compare the findings with data published for other countries.

The retrospective analysis included data on a total of 24 monochorionic twin pregnancies delivered at the Department between January 1998 and May 2002. The data retrieved from the maternity ward birth register included the ultrasound establishment of chorionicity, demographic data, complications of the pregnancy (presence of twin-to-twin-transfusion syndrome, intrauterine growth restriction, and threatened or actual preterm labor rate), and pregnancy outcome. Perinatal morbidity and mortality were also analyzed.

The establishment of chorionicity by ultrasound was accurate in all 24 monochorionic twin pregnancies. Five twins died in the perinatal period, and two in early neonatal period. The median gestational age at delivery was 35 weeks, ranging 29 to 38 weeks, and median birth weight was 1,990 g, ranging from 740 to 3,000 g. Intrauterine growth restriction was present in 18 cases, whereas twin-to-twin-transfusion syndrome complicated 2 monochorionic twin pregnancies. Symptoms of threatened preterm labor were present in 19 women, whereas actual preterm delivery rate was 16 out of 24.

The diagnosis of monochorionic twin pregnancy can be reliably made by ultrasound. Monochorionic twin pregnancies are characterized by a high complication rate, with threatened and actual preterm labor and delivery as the most common complications. These pregnancies are also accompanied with high perinatal mortality and morbidity.