The effect of late-gestational anemia on maternal and neonatal outcomes in twin pregnancies: a retrospective cohort study.

BACKGROUND

Due to their unique physiology, twin pregnancies face complex anemia-related risks. While anemia's impact is documented in singleton pregnancies, evidence in twins remains scarce. This study assessed the impact of late-gestational anemia on maternal and neonatal outcomes in twin pregnancies.

METHODS

This retrospective cohort study included 3,097 twin gestations delivered at Northwest Women's and Children's Hospital in China from 2018 through 2022. Multivariable logistic regression and generalized estimating equations were used to analyze the associations.

RESULTS

The prevalence of anemia in late gestation twin pregnancies was 32.39% (1,003/3,097), with moderate-to-severe anemia accounting for 50.25% of cases. Late-gestational anemia was associated with increased maternal risks of preterm birth (aOR: 1.46; 95% CI: 1.13-1.88), early preterm birth (aOR: 1.56; 95% CI: 1.26-1.93), postpartum hemorrhage (aOR: 1.84; 95% CI: 1.28-2.64) and blood transfusion (aOR: 2.60; 95% CI: 1.78-3.79). Neonates of anemic mothers had higher risks of low birth weight (aOR: 1.17; 95% CI: 1.02-1.34), very low birth weight (aOR: 1.38; 95% CI: 1.02-1.88), large for gestational age (aOR: 1.77; 95% CI: 1.09-2.86), small vulnerable newborns (aOR: 1.41; 95% CI: 1.08-1.84), 1-minute Apgar scores ≤7 (aOR: 1.87; 95% CI: 1.31-2.66) and 5-minute Apgar scores ≤7 (aOR: 2.57; 95% CI: 1.21-5.47). Moderate-to-severe anemia further increased the risk for very preterm birth (aOR: 1.57; 95% CI: 1.06-2.33).

CONCLUSIONS

Late-gestational anemia is prevalent in twin pregnancies and heightens the risk of adverse maternal and neonatal outcomes, with risks amplified in moderate-to-severe cases.