Birthweight Discordance Among Twins Born in Lagos, Nigeria

Background: Significant differences in twin birth weights may influence the perinatal outcome in twin pregnancies. Objective: To assess the factors associated with twin birth weight discordance in Lagos, Nigeria. Methods: A descriptive, cross-sectional study was conducted among women and their twins delivered in three health facilities in Lagos State between July and December 2023. Discordance was calculated for each pair as a percentage of the heavier twin [discordance (%) = 100 (birth weight difference/ birth weight of the heavier twin)]. A twin pair was designated discordant if one of the pair's weights was smaller by 15% or more. Results: One hundred and fifty-eight women and their 316 babies were recruited for this study. Of these, 96 (60.8%) mothers were under 35 years of age, 110 (69.6%) had been booked for antenatal care, 90 (57.0%) were primiparous, 52 (32.9%) had tertiary education, and 48 (30.4%) experienced various complications during pregnancy. The frequency of birth weight discordance was 38.0%. Hypertensive disorders of pregnancy (aOR = 4.99, 95%CI = 2.05 – 11.62, p<0.001), primiparity (aOR = 3.31, 95%CI = 1.53 – 7.16, p = 0.002), secondary level of education and below (aOR = 2.69, 95%CI = 1.14 – 6.24, p = 0.024) and same-sex twins (aOR = 2.51, 95%CI = 1.17 – 5.36, p = 0.018) were associated with birth weight discordance among twins. Conclusion: The birth weight discordance rate was high in Lagos, Nigeria. There is a need to monitor pregnant women for antenatal care closely to avoid pregnancy-related complications.