Maternal Circulating Angiogenic Factors in Twin and Singleton Pregnancies

Objective The purpose of this study was to compare longitudinally sampled maternal angiogenic proteins between singleton and twin pregnancies. Study Design Placental growth factor (PlGF), soluble feline McDonough sarcoma (fms)-like tyrosine kinase (sFlt)-1, and soluble endoglin from healthy pregnant women were quantified at 10, 18, 26, and 35 weeks' gestation (n = 91), and during the third trimester (31-39 weeks) and at delivery (33-41 weeks; n = 41). Geometric means and 95% confidence intervals were calculated for gestational age-adjusted angiogenic protein concentrations and compared between matched twin and singleton pregnancies. Results Maternal sFlt-1 concentrations and the sFlt-1/PlGF ratio were higher in twins than singletons across pregnancy and at delivery, with the greatest differences at week 35 (sFlt-1: 36,916 vs 10,151 pg/mL; P P P Conclusion Higher maternal antiangiogenic proteins in twin than singleton pregnancies does not appear to be due to greater placental mass in the former, and may be one explanation for the increased risk of preeclampsia in women carrying multiple gestations. Determining whether women with a history of multiple gestations have an altered cardiovascular disease and breast cancer risk, like those with a history of preeclampsia, is warranted.