Neonatal Outcomes in Twin Pregnancies with Birthweight Discordance:

Objectives: This study aimed to evaluate neonatal outcomes associated with birthweight discordance in twin pregnancies managed at a regional tertiary care centre in Oman. Methods: This five-year retrospective cohort study (2020-2024) was conducted at Nizwa Hospital, Nizwa, Oman, and included twin pregnancies of ≥24 weeks' gestation. Birthweight discordance was defined as ≥20%. Multivariable logistic regression analysis was performed, adjusting for gestational age at delivery, chorionicity, preeclampsia and gestational diabetes mellitus. Results: A total of 226 twin pregnancies were included, of which 45 (19.9%) had birthweight discordance ≥20%. Discordant pregnancies were delivered at an earlier gestational age than non-discordant pregnancies (34.2 ± 2.9 versus 35.3 ± 2.2 weeks; P = 0.017). NICU admission was more frequent in the discordant group (60.0% versus 31.5%; P <0.001), as was the composite adverse neonatal outcome (62.2% versus 33.1%; P <0.001). Birthweight discordance ≥20% remained independently associated with the composite adverse neonatal outcome (adjusted odds ratio [aOR] = 2.74, 95% CI: 1.21-6.25; P = 0.016), while increasing gestational age at delivery was protective (aOR = 0.47 per additional week, 95% CI: 0.37-0.59; P <0.001). Conclusion: Birthweight discordance ≥20% was associated with adverse neonatal outcomes in twin pregnancies, with this association largely mediated by prematurity.