Articles

Neonatal Morbidity in Growth-Discordant Monochorionic Twins: Comparison Between the Larger and the Smaller Twin

Enrico Lopriore^a1 c1, Carolien Sluimers^a2, Suzanne A. Pasman^a2, Johanna M. Middeldorp^a2, Dick Oepkes^a2 and Frans J. Walther^a1

^a1 Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands

^a2 Division of Fetal Medicine, Department of Obstetrics, Leiden University Medical Center, Leiden, The Netherlands

Abstract

Fetal growth restriction in singletons has been shown to enhance fetal lung maturation and reduce the risk of respiratory distress syndrome due to increased endogenous steroid production. However, data on lung maturation in growth-discordant monochorionic (thus, identical) twins are lacking. Our objective was to compare the risk of severe neonatal morbidity between the larger and the smaller twin in monochorionic twins with birth weight discordance (BWD). We included in the study all consecutive monochorionic diamniotic pregnancies with severe BWD (≥25%) and two live-born twins delivered at our center (n = 47 twin pairs). We compared the incidence of neonatal morbidity, particularly respiratory distress syndrome (RDS), and cerebral lesions between the larger and the smaller co-twin. The incidence of severe neonatal morbidity in the larger and smaller twin was 38% (18/47) and 19% (9/47), respectively (odds ratio (OR) 2.66, 95% confidence interval (CI) 0.94–7.44) and was due primarily to the higher incidence of RDS, 32% (15/47) and 6% (3/47), respectively (OR 6.88, 95% CI 1.66–32.83). In conclusion, this study shows that the larger twin in monochorionic twin pairs with BWD is at increased risk of severe neonatal morbidity, particularly RDS, compared to the smaller twin.

(Received November 09 2011)

(Accepted March 01 2012)

Keywords:

• monochorionic twins;
• selective intrauterine growth restriction;
• birth weight discordance;
• neonatal morbidity;
• respiratory distress syndrome;
• cerebral lesions

Correspondence:

^c1 address for correspondence: Enrico Lopriore, Division of Neonatology, Department of Pediatrics, J6-S, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands. E-mail: e.lopriore@lumc.nl