Fetal haemoglobin concentration and mean red cell volume are not related to the maternal values at 18-25 weeks' gestation.

A cross-sectional study of 64 women and their fetuses undergoing cordocentesis at 18-25 weeks showed no significant correlation between maternal and fetal Hb or MCV and no relationship between these measurements and fetal abdominal circumference. We found no evidence for a nutritional or physiological association between maternal and fetal haematological status.