Increased expression of vascular endothelial growth factor in cardiac structures of fetus with hydrops as compared to...

The hypothesis that severe fetal hydrops is caused by an excess of vascular endothelial growth factor (VEGF), mainly produced in the fetal heart, is tested.

Immunohistochemical VEGF-stained postmortem biopsies from the right ventricle and right atrium of 8 hydropic fetuses were compared to those of 8 nonhydropic fetuses. The endocardium, myocardium, epicardium, endothelium, and vascular smooth muscle cells were scored on intensity of VEGF-staining. The Mann-Witney test was used to test for significancy (p < 0.05) of the differences in staining. Increased vascularization as a result of VEGF was measured in both groups by standard randomization count.

The endocardium, epicardium and endothelium of the coronary vessels showed significantly (p < 0.05) more intense VEGF-staining in the hydrops group than in the control group. The atria showed more intense staining than the ventricles in both groups. The hydropic fetuses showed a significantly increased number of coronary vessels in the myocardium. These vessels contained more blood cells than the coronary vessels in nonhydropic fetuses.

The fetal heart appears to be a major source of excess VEGF in fetal hydrops.