Infants' blood volume in a controlled trial of placental transfusion at preterm delivery

To investigate whether it was possible to promote placental blood transfer to infants at preterm delivery by (1) delaying cord clamping, (2) holding the infant below the placenta, and (3) administering an oxytocic agent to the mother, we measured the infants' blood volumes.

Randomized study.

Forty-six preterm infants (gestational age: 24[0/7] to 32[6/7] weeks) were assigned randomly to either placental blood transfer promotion (delayed cord clamping [DCC] group, ie, > or =30 seconds from moment of delivery) or early cord clamping (ECC) with conventional management (ECC group). Eleven of 23 and 9 of 23 infants assigned randomly to DCC and ECC, respectively, were delivered through the vaginal route. The study was conducted at a tertiary perinatal center, the Queen Mother's Hospital (Glasgow, United Kingdom).

The infants' mean blood volume in the DCC group (74.4 mL/kg) was significantly greater than that in the ECC group (62.7 mL/kg; 95% confidence interval for advantage: 5.8-17.5). The blood volume was significantly increased by DCC for infants delivered vaginally. The infants in the DCC group delivered through cesarean section had greater blood volumes (mean: 70.4 mL/kg; range: 45-83 mL/kg), compared with the ECC group (mean: 64.0 mL/kg; range: 48-77 mL/kg), but this was not significant. Additional analyses confirmed the effect of DCC (at least 30 seconds) to increase average blood volumes across the full range of gestational ages studied.

The blood volume was, on average, increased in the DCC group after at least a 30-second delay for both vaginal and cesarean deliveries. However, on average, euvolemia was not attained with the third stage management methods outlined above.