Twin-to-twin transfusion syndrome: an antiangiogenic state?

Objective: An imbalanced chronic blood flow between the donor and recipient twin through placental vascular anastomoses is the accepted pathophysiology of twin-to-twin transfusion syndrome (TTTS). Vascular endothelial growth factor receptor-1 (VEGFR-1) mRNA is overexpressed only in the syncytiotrophoblast of the donor twin in some cases of TTTS. This study was conducted to determine maternal plasma concentrations of placental growth factor (PlGF), soluble VEGFR-1, and soluble endoglin (s-Eng) in monochorionic-diamniotic pregnancies with and without TTTS. Study Design: This case-control study included monochorionic-diamniotic pregnancies between 16-26 weeks with and without TTTS. Maternal plasma concentrations of PlGF, sVEGFR-1, and s-Eng were determined with ELISA. A P value < .05 was considered statistically significant. Results: Patients with TTTS had higher median plasma concentrations of s-Eng (14.8 ng/mL vs 7.8 ng/mL; P < .001) and sVEGFR-1 (6383.1 pg/mL vs 3220.1 pg/mL; P < .001]; and lower median plasma concentrations of PlGF (115.5 pg/mL vs 359.3 pg/mL; P = .002) than those without TTTS. Conclusion: We propose that an antiangiogenic state may be present in some cases of TTTS.