Hematologic values of fetal blood obtained by means of cordocentesis.

Fetal blood values were evaluated from 541 cordocenteses. Simple regressions were used to find a correlation between blood values and gestational age. We found a linear increase in hemoglobin concentration and hematocrit throughout gestation; a linear decrease of the mean corpuscular volume with the gestation was evidenced as a regular decrease in mean corpuscular hemoglobin. Lastly, the mean corpuscular hemoglobin concentration was constant during the gestation; a linear increase of the platelet count and the nucleated cells was also evidenced. We suggest that each fetal medicine unit should have its own reference ranges. It will permit to accurately diagnose fetal infection, fetal anemia, or any fetal disease where alterations of hematopoiesis have been described.