Blood volume increase

Gunther (1957) weighed infants for up to 20 minutes after birth, with the umbilical cord intact allowing ongoing placental circulation.  Fluctuations in weight occurred in response to uterine contractions, elevation of the baby above or below the mother's uterus, and pulsations of the cord.

Most interesting of Gunther's findings were the annotations of the weight gain/loss tracings.  In figure 1 (below) postnatal activity and weight profile are shown for a baby who started crying only 9 minutes after birth, and with pulsations of the cord continuing for 19 minutes after birth.

What would have been the Apgar scores and fate of this child had the cord been cut  within the first minute after birth?

Likewise, in figure 3 (left), resuscitation was started within one minute on an infant described as "slow to cry."   Crying began more than 6 minutes after birth following a uterine contraction and additional weight gain from placental blood.  Pulsations of the cord continued throughout the 10 minute interval shown in the graph.   This would surely have been another infant described as severely depressed by Apgar, and with an ominous outcome.

Gunther commented, "These records confirm once more that, if the cord is left untied, a baby will usually increase his blood volume by a significant amount."  She compared her findings to those of Haselhorst (1929) and Allmeling (1930), noting that placental transfusion increased a newborn's weight by by 0.8 to 4.7 percent, which (assuming blood volume is about 10 percent of an infant's weight) amounts to as much or more than 40 percent of the baby's blood volume.