THE SIGNIFICANCE OF BIRTH-WEIGHT DIFFERENCE IN DISCORDANT TWINS - A LEVEL TO STANDARDIZE

Objective. To evaluate the significance of different degrees of birth weight discordance in twin pregnancies. Design. Population based study . Method Three hundred and eighty-four twin gestations over 20 weeks o f gestation during a two-year period ending in 31.12.1995 were retrosp ectively analyzed. Twins were stratified into six categories according to the percent difference in infant birth weight. The difference in p ercents was calculated from the larger twin; (Birth weight of larger t win - Birth weight of smaller twin)/Birth weight of larger twin and mu ltiplied with 100. The relationship between different categories and t he subsequent perinatal and neonatal outcomes was assessed. Results. A mong 384 pairs thirteen patients were identified to have single fetal demise and fourteen patients were documented to have dead fetuses of b oth twin pairs. Of 357 twin gestations studied 137 (38.4%) had discord ance of <10% and 36 experienced discordance of >30% (10.1%). The frequ ency of low APGAR score (<7) in women with >30% discordance was higher than that of <10% group (16.7% vs. 9.5%). Intensive care for infants was required in 30 infants with >30% birth weight discordance (41.7%) and in 24 cases with <10% birth weight discordance (8.8%). Thirty-thre e percent of cases with discordance of >30% experienced neonatal morta lity whereas the corresponding figure for patients with <10% discordan ce was 1.5%. Conclusion. We postulate that definition of discordant gr owth in twin gestations should be categorized with respect to gestatio nal week since the level of discordance prejudicing fetal or neonatal jeopardy may vary in different stages of pregnancy.