Assessment of vascular endothelial growth factor, basic fibroblast growth factor, and transforming growth factor levels in amniotic fluid.

Objective: To measure amniotic fluid levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and transforming growth factor (TGF)-beta2 and to characterize their levels with respect to advancing gestational age and pregnancy-related complications.

Study Design: Amniotic fluid was collected from a total of 37 patients, 2 of whom had twin pregnancies. Twenty-seven specimens were collected in the second trimester and 10 specimens were collected in the third trimester. VEGF, bFGF and TGF-beta2 were isolated from centrifuged amniotic fluid and quantified using commercially available ELISA kits. Concentrations of growth factors were expressed in pg/mL.

Results: The growth factors under investigation were present in most but not all amniotic fluid specimens throughout pregnancy. The levels of VEGF, bFGF and TGF-beta2 were inconsistent and did not show a statistically significant association with gestational age, number of fetuses, or the presence of hypertension and/or diabetes. One significant finding emerged from the data: smokers had significantly higher amniotic fluid levels of VEGF compared to nonsmokers (p = 0.03).

Conclusion: VEGF, bFGF and TGF-beta2 are detectable in second and third trimester amniotic fluid. Smoking appears to correlate with increased amniotic fluid VEGF during pregnancy. VEGF may represent a molecular marker of hypoxia and is an interesting focus for future investigation.