The Clinical Assessment of Discordant Fetal Growth in Dichorionic and Monochorionic Twins

Cho, Jae Sung; Kim, Jae Wook; Kim, Sei Kwang; Kim, Suk Young; Kim, In Kyu

Abstract

OBJECTIVE
The purpose of this study was to evaluate the clinical course of discordant fetal growth and perinatal outcome in relation to dichorionic and monochorionic twin for different degrees of birth weight difference.
METHODS
Between Jan. 1992 and Dec, 1997, 154 twin pairs were born at Yonsei medical center and there were 36 pairs of twins which had 20% or more birth weight difference. The placental examination were performed routinely on all multiple births and 13 pairs of dichorionic twins and 23 pairs of monochorionic twins were consisted of the study population. These twin pairs were divided into three groups based on birth weight difference: 20-29%(as group A), 30-39%(as group B), and 40% or more(as group C). Gestational age, birth weight, gender and perinatal outcomes were observed for each twin pairs.
RESULTS
The perinatal death in the monochorionic twin pairs showed 9(34.6%) as group A, 4(50%) as group B, and 5(41,7%) as group C and in the dichorionic twin paus 1(10.0%) as youp A, 0 as group B and 5(62.5%) as group C. Up to 40% of birth weight difference, dichorionic twin pairs showed good perinatal outcomes compared with monochorionic twin pairs but over 40% or more of birth weight diffaence, however there were no significant difference of perinatal outcomes by chorionicity. In the monochorionic twin pairs, the cause of perinatal death showed 3 cases of prematurity, 2 cases of congenital anomalies and 2 cases of IIOC and 2 cases of cord lesions in group A whenas in the group B and C 3 cases of prematurity and 6 cases of congenital anomalies. In the dichorionic twin pairs, different-sex twin pairs showed no perinatal death in all three groups but in same-sex twin pairs there were 6 perinatal deaths.
CONCLUSION
More recent improved fetal ultrasonographic surveillance such as determination of chorionicity, identification of fetal sex and evaluation of fetal anomalies help to make a clinical decision in growth discordant twin up to 40% of weight difference each other.