Delivery of monochorionic twins in the absence of complications: Analysis of neonatal outcomes and costs

摘要

Monochorionicity is associated with increased adverse perinatal outcomes when compared with dichorionicity. The rate of prematurity in monochorionic twins is also higher and contributes to perinatal complications. Many obstetricians recommend elective preterm delivery in monochorionic twin pregnancies to avoid stillbirth and other perinatal complications. However, other obstetricians disagree, and it remains unclear whether uncomplicated monochorionic twin pregnancies should be delivered preterm. The authors of the present study hypothesize that the risk of prematurity associated with elective delivery at less than 37 weeks of gestation among monochorionic-diamnionic (MCDA) twins is greater than the risk of stillbirth. If so, elective preterm delivery of MCDA twins without medical indications for delivery is not warranted.The aim of this retrospective cohort study was to determine the optimal timing of delivery in a cohort of MCDA twins that did not have medical indications for delivery. Data of patients with twin pregnancies delivered between 2000 and 2009 at 18 hospitals in Utah were obtained. Gestational age-specific prospective risks of perinatal mortality were calculated for twin deliveries from 20 to more than 37 gestational weeks. Neonatal outcomes and hospital care charges were compared between MCDA twins with nonindicated deliveries who were born during a given gestational week and those born the subsequent week.The study population was composed of 1704 MCDA twins and 5894 dichorionic-diamnionic twins. After 28 completed weeks, there was no difference between the 2 groups in the gestational week-specific prospective risk of perinatal mortality. Among pregnancies with nonindicated deliveries, 3956 (80.7%) were infants from dichorionic-diamnionic pregnancies and 948 (19.3%) were from MCDA pregnancies. The risk of severe neonatal morbidity, perinatal mortality, and hospital costs of neonatal care were greater for fetuses delivered at less than 37 weeks compared with fetuses born at 37 weeks or more.These findings suggest that that monochorionic twins without a medical indication for delivery should not be delivered before 37 weeks of gestation.