Lower placental growth factor and higher free β-hCG and PAPP-A levels in the fetal circulation of near-term pregnancies complicated with severe preeclampsia

Background: An imbalance between anti- and angiogenic factors during early placentation is key for the development of preeclampsia. Nevertheless, the majority of studies addressing this issue relate to maternal blood and not the fetal circulation. Objective: To measure placental growth factor (PlGF), free beta human chorionic gonadotropin (β-hCG), and pregnancy-associated plasma protein-A (PAPP-A) levels in the fetal circulation of near-term pregnancies complicated with severe preeclampsia (n = 20), and their controls matched for parity, and maternal and gestational age. Method: Upon delivery, a blood sample was withdrawn from the umbilical artery and vein of each case and its control in order to measure the proposed analytes using direct fluoroimmunoassay. Results: Preeclampsia cases showed significantly lower median PlGF levels in fetal circulation as compared to controls (25.2 versus 36.9 and 23.6 versus 33.9 pg/mL, artery and vein, respectively, p < 0.05). Contrarily, cases displayed higher concentrations of PAPP-A (1024.0 versus 720.9 [median] and 1027.0 ± 298.4 versus 690.3 ± 401.9 mIU/L, artery and vein, respectively, p <0.05), and free β-hCG (mean: 33.9 ± 4.3 versus 17.2 ± 4.0 and 30.1 ± 5.2 versus 13.7 ± 3.3 ng/mL, artery, and vein respectively, p <0.05). Conclusion: Lower PlGF and higher PAPP-A and free β-hCG levels were found in the fetal circulation of near-term severe preeclamptic pregnancies. There is a need for more research in this regard.