Perinatal outcomes of birth weight discordance according to the chorionicity

Kil, Ki Chul; Lee, Gui Se Ra; Kang, Young Hwa; Kim, Yeon Hee; Kim, Sa Jin; Shin, Jong Chul

Abstract

OBJECTIVE
The purpose of this study was to examine the association between intrapair birth weight discordance and perinatal outcomes according to the chorionicity.
METHODS
Twin births in St. Vincent's Hospital of Catholic University of Korea for the period 2000~2007 were retrospectively studied. Discordance was defined as an intertwin birth weight difference > or =20% and concordance was defined as weight difference <20% calculated from the larger newborn. Perinatal outcomes were compared between discordant and concordant pairs in monochorio-diamnionic and dichorionic twins.
RESULTS
Among 38 monochorionic twin births, 34.2% was discordant and 66.8% was concordant. Among 144 dichorionic twin birth, 9.9% was discordant and 91.9% was concordant. The incidences of intrauterine fetal death (FDIU), twin-to-twin transfusion syndrome (TTTS), intrauterine growth restriction (IUGR) and neonatal hypoglycemia of discordant group of monochorionic twins were statistically increased compared with concordant group of monochorionic twins. The incidences of IUGR and neonatal hypoglycemia were statistically increased in the discordant group of dichorionic twins compared with concordant group of dichorionic twins. The others were not shown statistically significant between two groups in the both chorionic twins.
CONCLUSIONS
Birth weight discordance in monochorionicity seems to predict fetal death, TTTS, IUGR and newborn hypoglycemia. Birth weight discordance in dichorionicity does not seem to be good predictor of adverse perinatal outcomes except IUGR and neonatal hypoglycemia.