Small for gestational age in twin pregnancies and the risk of offspring pediatric neurologic morbidity

Objectives: Small for gestational age (SGA) singletons are at increased risk for neurodevelopmental abnormalities. Scarce data exist regarding the long-term implications of SGA in twins. We opted to study the association between SGA of one twin and long-term neurologic related morbidity in dichorionic diamniotic twins. Study design: A population-based retrospective cohort study including consecutive dichorionic diamniotic twins, born between the years 1991 and 2021 at a tertiary medical center was conducted. Total and subtypes of neurologic related pediatric hospitalizations among SGA versus non-SGA twins were compared. A Kaplan–Meier survival curve was used to compare the cumulative neurologic morbidity incidence, and a Cox proportional hazards model was constructed to adjust for confounders. Results: The study population included 4222 newborns; 180 (4.3%) were SGA. Rate of long-term neurologic related hospitalizations was comparable between the two groups (8.7 vs. 8.0%, p = 0.755; Kaplan–Meier survival curve Log-rank p = 0.652). Using a Cox proportional hazards model, controlling for gender and birth order, no association was found between SGA and the risk for subsequent neurologic pediatric morbidity of the offspring (Adjusted HR = 1.0, 95% CI 0.6–1.8, p = 0.973). Conclusions: SGA is not associated with an increased risk for long-term pediatric neurologic morbidity in dichorionic diamniotic twins.