The concentration of hemoglobin in the plasma of normal human subjects has recently been reexamined in our laboratory, employing modified methods for blood sampling and for hemoglobin measurement.1,2 Study of 25 ambulatory adults revealed a mean value for plasma hemoglobin concentration (PHgbC) of 0.31 mg. per 100 ml., with a range of 0.16 to 0.58 mg. per 100 ml.
As part of a broad study of PHgbC in normal subjects, preliminary observations were made on blood samples obtained from 6 women at the time of parturition and from the placental segment of the umbilical vein immediately after separation of the newborn infants. Although PHgbC was within the normal range for the 6 maternal samples, all of the umbilical vein samples yielded elevated values, half of them in the range 10 to 20 times the mean value for normal adults. Since to our knowledge this phenomenon had not been previously
ANDERSON RL, CHAPLIN H. Plasma Hemoglobin Concentration in Umbilical Cord Blood. Am J Dis Child. 1963;105(1):19-26. doi:10.1001/archpedi.1963.02080040021004