Abstract

Background: Twin-to-twin transfusion syndrome (TTTS) is a severe complication in monochorionic twin pregnancies, leading to high perinatal morbidity and mortality. Fetoscopic laser photocoagulation (FLP) is the gold standard treatment; however, fetal demiseremains a concern. The soluble vascular endothelial growth factor receptors, sVEGFR-1 and sVEGFR-2, play a crucial role in regulating angiogenesis and vascular function. This study evaluates changes in sVEGFR-1 and sVEGFR-2 levels before and after FLP and explores their role in predicting fetal demise post-surgery. Objective: Therefore, this study aims to evaluate pre- and post-surgical changes in sVEGFR-1 and sVEGFR-2 levels in TTTS cases treated with FLP and determine their predictive value for fetal demiseafter surgery. Methods: A prospective longitudinal study was done with 27 pregnant women with TTTS stage II-IV according to Quintero classification from 16 to 26 weeks of gestation undergoing FLS. Among them, 11 cases were carried out coagulation the placental vascular anastomoses, 16 cases were done ablation umbilical cord for the selective fetal reduction because of TTTS stage IV, selective intrauterine growth restriction (sIUGR) or proximate cord insertions. All the studies subject investigated the soluble levels of biomarkers. We quantified plasma levels of VEGF-R1, VEGF- R2 in twin pregnant with TTTS before and one week after surgery by ELISA. Many factors included maternal age, gestational age at surgery, stage of TTTS, placental location, level of polyhydramnios, FLS methods, sIUGR, amount of amniotic fluid drawn, duration of surgery, change of maternal circulating biomarker levels were analyzed to find out the association with fetal demise after FLS. Results: Statistics showed that VEGF-R1 levels were significantly decreased after surgery and change in soluble VEGF-R1 levels after surgery had a difference between the group of fetal demise and non-fetal demise. ROC curve showed that degree of VEGF-R1 levels reduction after surgery were higher, the risk of fetal demise was bigger (AUC: 0.8472), in which, cut-off point of degree of VEGF-R1 levels reduction after surgery was 36.5% (sensitivity: 66.67%, specificity: 95.83%). Conclusion: Our data suggest that change in VEGF-R1 after surgery could play a prognostic role of fetal demise after fetoscopic laser surgery.

Key words: Twin-to-twin transfusion syndrome, laser photocoagulation, sVEGFR-1, sVEGFR-2, fetal loss, prognosis.