The sFlt-1/PlGF Ratio at 12, 24, and 32 Weeks Gestation in Twin Pregnancies as a Predictor of Late Preterm Birth and Perinatal Event Secondary to Prematurity.

Background: Preterm birth impacts 60% of twin pregnancies, with the subsequent risk of complications in both newborns secondary to the immaturity of organs. This study aims to assess the utility of the sFlt-1/PlGF ratio throughout pregnancy in predicting late preterm birth and adverse perinatal outcomes related to prematurity in twin pregnancies. Methods: This is a prospective cohort study developed at a tertiary hospital. All pregnant women with a twin pregnancy who signed the informed consent were included. The sFlt-1/PlGF ratio was measured at 12, 24, and 32 weeks' gestation. Results: Seventy patients were included, from which 54.3% suffered late preterm birth. Results revealed a significant difference in sFlt-1/PlGF ratio at week 32 between term and preterm groups, with a one-unit increase associated with a 1.11-fold increase in the probability of preterm birth. The sFlt-1/PlGF ratio at week 32 alone presented considerable predictive capacities (sensitivity of 71%, specificity of 72%, a PPV of 75%, and an NPV of 68%. Similarly, at week 24, a one-unit increase in sFlt-1/PlGF ratio was associated with a 1.24-fold increase in the probability of adverse perinatal events due to prematurity. Combining parity, maternal age, conception method, BMI, and chorionicity, the model yielded better predictive capacities (sensitivity of 82%, specificity of 80%, PPV of 58%, NPV of 93%). Conclusions: The potential of the sFlt-1/PlGF ratio as a predictive tool for preterm birth and adverse perinatal outcomes secondary to prematurity in twin pregnancies is underscored.