1. The objectives of the study were: (i) to investigate the serum concentrations of vascular endothelial growth factor (VEGF) in pregnant and non-pregnant women; and (ii) to study the relationship between the levels of maternal serum VEGF and the serum concentrations of human chorionic gonadotrophin (hCG) and progesterone during the first trimester.
2. Total immunoreactive VEGF was measured by competitive RIA using recombinant human VEGF165 and a polyclonal antiserum. Serum VEGF was measured in 60 non-pregnant women of child-bearing age. These data were compared with serum VEGF measured in 363 women between 41 and 91 days of gestation.
3. The median serum VEGF concentration was 1.10 μg/l (interquartile range 0.91–1.30) in the nonpregnant women and 2.13 μg/l (interquartile range 1.62–2.77) in the pregnant women. Serum levels of VEGF were significantly higher among the pregnant cohort (P < 0.0001). Serum VEGF concentration was positively correlated with gestational age, increasing until ten completed weeks of pregnancy. Serum VEGF was negatively correlated with maternal height and weight, and positively correlated with serum hCG and serum progesterone (P ≤ 0.0001 in all cases). Serum VEGF was lower in the pregnant women who smoked (P = 0.06).
4. Our data show a positive and highly significant correlation between maternal serum levels of VEGF and hormones reflecting placental function (hCG, progesterone). We speculate that VEGF production is increased by progesterone and hCG, and that VEGF has a positive influence on trophoblast development. VEGF may also be involved in the initiation of the maternal cardiovascular adaptation to pregnancy.