|| Checking for direct PDF access through Ovid
To investigate whether chorionic villus sampling (CVS) results in a proportional increase of alpha-fetoprotein (AFP) and fetal red cells in maternal blood.Blood samples were collected before and after CVS. The AFP concentration was measured and supervised automated microscopy of Kleihauer-Betke slides was applied to quantify fetal red cells.AFP analysis was performed in 53 paired samples and automated microscopic scanning in 59 paired samples. Median AFP concentrations before and after CVS were 12.0 μg/L (range 6.4-36.4) and 18.7 μg/L (range 8.2-668.9), respectively, indicating a significant increase (p < 0.0001). Median numbers of fetal red cells detected before and after CVS were 0 (range 0-36) and 0 (range 0-31), respectively. No significant increase of fetal cells was observed (p = 0.72). The delta (Δ) fetal red cells and the Δ AFP correlated poorly (ρ = -0.22, p = 0.11). The amount of villi correlated moderately with the Δ AFP (ρ = 0.32, p = 0.02) and did not correlate with the Δ fetal red cells (ρ = -0.11, p = 0.43).Although the AFP concentration after CVS increased, no increase of fetal red cells was detected. These findings suggest that CVS results in a leakage of proteins due to placental tissue damage, rather than increased trafficking of fetal cells.