(313) Adverse perinatal outcomes and mortality of small for gestational age infants in twin pregnancies

A population-based cohort study including all offspring of dichorionic diamniotic twin gestations, born between the years 1991-2021 at a tertiary medical center was conducted. Perinatal morbidity and mortality was assessed among SGA offspring and was compared to  non-SGA offspring of dichorionic diamniotic twin gestations. Infants with congenital malformations were excluded from the analysis. Using a multivariable generalized estimating equation (GEE) model was used to adjust for confounders such as gender and birth order.  

Results:

The study population included 4,222 newborns which met the inclusion criteria. Among them, 180 (4.3%) were SGA. SGA twins were at an increased risk for adverse perinatal outcome (table 1): The rate of low Apgar scores at 5 minutes ( < 7) were significantly higher in the SGA group (11.5% vs. 1.8%; p < 0.001). Significantly higher rates of intrauterine fetal death (IUFD) (11.7% vs. 0.4% in the control group; p < 0.001), as well as higher rates of postpartum death (PPD) (11.7% vs. 1.4%; p < 0.001) and higher rates of total mortality (23.3% vs. 1.8%; p < 0.001) were noted in the SGA group. Using a multivariable GEE model, the association between SGA and perinatal mortality remained significant while controlling for gender and birth order (adjusted OR 16.9 , 95% CI 11.1-25.7; p< 0.001, table 2).

Conclusion:

SGA in dichorionic diamniotic twins is associated with adverse perinatal outcome. Moreover, in our population, SGA in twins is an independent risk factor for perinatal mortality.