Obstetric outcome in twin gestation with reference to chorionicity

Abstract

INTRODUCTIONTwinning is one of the most interesting events occurring in human reproductive biology. At present, multiple pregnancy accounts for 3% of all the pregnancies (ACOG, 1998), out of which 94% are twins.In India, twins account for 1% of all pregnancies, but contribute to 10% of perinatal mortality.1,2 Twin pregnancies are also responsible for 12.2 % of preterm births and 15.4% of neonatal deaths. 3,4Over the last few decades, the incidence of twinning has been on the rise. This significant increase was not only due to the postponement of maternity, but also due to inadvertent use of ovulation induction drugs in artificial reproductive techniques. Perinatal morbidity and mortality was higher among multiple gestations due to ABSTRACT Background: Monochorionic twin pregnancies are at greater risk for growth abnormalities and other complications. This study aims to outline the obstetric problems faced by twins in general and also to determine the influence of chorionicity on pregnancy and perinatal outcome in twins. Objective of present study was to compare the obstetric and perinatal outcome between monochorionic and dichorionic twins. Methods: A clinical non-interventional prospective observational study was conducted in a tertiary care hospital over a period of 1 year. 232cases of twin pregnancies were followed up from first trimester. The antepartum complications, mode of delivery, presentation, pregnancy outcome, condition of babies and perinatal mortality were compared between mono-chorionic and dichorionic twins. Results: Among 232 cases of twins studied, 2/3rd were dichorionic and 1/3rd were monochorionic. The mean gestational age for Monochorionic (MC) twins was 33.2 weeks whereas it was 35.6 weeks for Dichorionic (DC) twins. Preterm delivery was significantly associated with mono-chorionicity. Elective CS was done more for MC twins compared to DC twins. The mean birth weight of MC twins was 1.7 kg compared to 2.1 kg among DC twins. Low APGAR scores were seen in 31.3% of MC twins compared to 15.8% of DC twins. The number of asphyxiated babies (12.5%), stillborn (7.5%) and macerated babies (10%) were more in MC group in comparison to DC group where it was (9.9%, 2.1%, 0.7%) respectively. Risk of IBN admissions were more in MC than DC twins. (31.3% Vs 21.1%) Adverse perinatal outcome was associated more with MC pregnancies (37.5%) than DC. (11.8%). Conclusions: Mono-chorioncity was significantly associated with pregnancy complications and adverse perinatal outcome. Hence early diagnosis of chorionicity and referral to a tertiary centre with fetal medicine unit and newborn care is very important in reducing morbidity and perinatal mortality among MC twins.