Sex Differences and Sustained Excess in Mortality among Discordant Twins in Matlab, Bangladesh: 1977–1985

This paper reports findings from a study that compared survival of 204 pairs of liveborn twins of different sex and random sample of 2371 singleton livebirths from the same population in Matlab Bangladesh during 1977-85. The different-sex twins showed no evidence of sex differential in neonatal survival. They had a neonatal mortality of 287 and an infant mortality of 468 both/1000 livebirths. These rates were respectively 5 and 4 times the rate for singletons in this study. Survival from 12 months through 9 years was similar overall for both different-sex twins and singletons of each sex. However higher female mortality was seen among different-sex twins after the 1st months of life. This differential was most prominent during the 2nd year of life and appeared wider than that observed for the singletons. (authors modified)