Influence of the vascular endothelial growth factor on the development of severe pre-eclampsia or HELLP syndrome

The aim of this study was to compare the maternal serum concentrations of the vascular endothelial growth factor (VEGF) in patients whose pregnancies were complicated by pre-eclampsia or HELLP syndrome with those of healthy pregnant controls and to study its relationship with the hormonal and nutritive function of the placenta.

The study group consisted of 30 primaparae who suffered from either severe pre-eclampsia (n = 16) or from HELLP syndrome (n = 14). 30 healthy pregnant woman of the same gestational age served as control group. Maternal serum VEGF concentrations were determined by using a commercially available Sandwich immunoassay (Quantikine(®), R&D Systeme, Wiesbaden, Germany). Estradiol, estriol and progesterone serum levels were measured by performing a radioimmunoassay (Biermann, Bad Nauheim, Germany).

The mean serum VEGF concentration of the study group (172.0 ± 98.9 pg/ml) was significantly increased, compared with the mean serum VEGF concentration of the control group (41.4 ± 30.5 pg/ml) (U test: P < 0.001). In the subgroup of the study patients with HELLP syndrome, significantly lower VEGF levels were measured than in patients suffering from severe pre-eclampsia (109.2 ± 68.5 pg/ml vs. 219.0 ± 72.9. U test: P < 0.05). In all study and control patients, a significantly positive correlation between serum estradiol and VEGF concentration could be found (Spearman's rank correlation: P < 0.05).

An increased placental expression due to local hypoxia and an increased extraplacental production, e.g., in endothelial cells of the fetal or maternal vascular system, in macrophages or in smooth muscle cells, could be discussed as causes for the raised serum VEGF concentration in patients suffering from severe pre-eclampsia or HELLP syndrome.