The aim of the present study was to analyze the concentrations of endothelial precursor cells (EPCs) during the 3 trimesters of normal pregnancy and to compare the EPC counts in women with normal pregnancy, gestational diabetes, and gestational hypertension.

The study was conducted on 21 pregnant women with single pregnancies (age range, 22 to 35 years). EPCs were quantified by flow cytometry. The subjects were divided into 3 groups, each consisting of 7 subjects: patients with gestational diabetes; patients with gestational hypertension; patients with normal pregnancy.

A progressive increase was found in the concentrations of EPCs during pregnancy in healthy women. In the third trimester of pregnancy, the number of CD34⁺ cells was significantly lower in patients with gestational diabetes than in hypertensive patients and controls; no significant differences were found between the levels of circulating CD34⁺ cells in hypertensive patients and those in controls. There were no significant differences between the diabetic and hypertensive patients for the percentage of cells expressing CD133 and VEGFR2, whereas in both groups the percentage of CD133⁺/VEGFR2⁺ elements was significantly higher than in the healthy control subjects.

Our findings confirm that EPCs isolated from the maternal circulation increase gradually throughout the gestational trimesters. These cells were derived from the endothelial cells lineage, as demonstrated by CD133⁺/VEGFR2⁺ cell assay. Moreover, the concentration of EPCs in pregnant women with gestational diabetes and hypertension differs from that in subjects with a normal pregnancy, CD34⁺ cells being reduced but CD133⁺/VEGFR2⁺ cell concentrations being increased. These results not only substantiate recent insights into the mechanisms regulating maternal vascular modifications during pregnancy but also throw light upon the activation of different patterns in the mobilization of endothelial progenitor cells during pathologic states in which endothelial disorders occur.