Megakaryocytes in the foetal circulation and in cubital venous blood in the mother before and after delivery.
22 newborn infants delivered by Caesarean section were investigated in order to ascertain the number and morphology of megakaryocytes in the umbilical artery and vein. Averages of 65.5 and 47 MK per ml blood were found, respectively. 25% of MK in the artery and 8% in the vein had copious cytoplasm. Thus there was a significantly higher total number of MK and number of MK with copious cytoplasm in blood from the artery than from the vein (P less than 0.05). In blood from the aorta in 16 newborn infants we found an average of 28 MK per ml blood, 8% had copious cytoplasm. There was a significantly smaller number of MK in the aorta than in both the artery and the vein of the umbilical cord (P less than 0.05). There was the same percentage of MK with copious cytoplasm in the aorta as in the umbilical vein. The number of MK in cubital venous blood from the mother prior to delivery was 17.5 MK per ml and was significantly higher than about 3 months after delivery when it was 5 MK per ml blood, which is a normal value (P less than 0.05). In both series, 1.5% of MK had copious cytoplasm, as in a normal material.
D001011:Aorta; D002452:Cell Count; D002585:Cesarean Section; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008533:Megakaryocytes / Q000166:cytology; D011247:Pregnancy; D014469:Umbilical Arteries; D014471:Umbilical Veins