Role of respiration in effecting transfusion at cesarean section.

The transfer of blood from placenta to baby (placental transfusion) was examined in 29 full-term babies delivered by elective Cesarean Section. Events surrounding the delivery were carefully monitored using a stopwatch. Residual placental blood volume (RPBV) and change in hematocrit (Hct) were measured. In 13 infants held above the level of the placenta, the mean RPBV was significantly greater, and the change in Hct significantly lower, than in 16 infants held below the level of the placenta. Increasing duration of respiration resulted in increasing amounts of placental transfusion, even in those babies held just above the placenta. These results indicate that there are separate effects of gravity and respiration which facilitate a placental transfusion at Cesarean Section.