The Discordance of Intra-twin Birth Weight by Infantile Gender and Birth Order in Korea; 2008-2013 / 대한주산의학회잡지

PURPOSE: To investigate the incidence of intra-twin birth weight discordance and its association with infantile gender and birth order. METHODS: We used the data of birth from 2008 to 2013 of Korea Statistics (38,140 pairs of twins). Adjusted logistic regression analyses were performed to describe the birth weight discordance (> or =25%) according to infantile gender and birth order (twin A: 1st, twin B: 2nd). Birth weight discordance was calculated as 100 x (birth weight difference/birth weight of the heavier twin). RESULTS: Twin A (mean 2.431 kg) was heavier than twin B (mean 2.359 kg), and the weight difference was 0.281 kg on average. Overall incidence of birth weight discordance was 8.3 percent. The incidence of discordance was 8.8 percent among unlike-sexed pairs and 8.0 percent among like-sexed pairs. Twins with birth weight A> or =B (10.2 percent) showed higher incidence of discordance than twins with birth weight A or =B) as compared to like-sexed twins (female-female) with birth weight (A