Role of Respiration in Effecting Placental Transfusion at Cesarean Section

Abstract

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.

Neonatal polycythaemia: critical review and a consensus statement of the Israeli Neonatology Association

“… Onset of respiration . This point is controversial, as onset of respiration (through generating a negative intrathoracic pressure and presumably increasing the placental–foetal transfusion process) has been found to have little (13), or not effect (11) upon blood volume at birth. Presence or not of intrauterine hypoxia . Acute intrapartum and intrauterine asphyxia can be accompanied by an increase in HCT (presumably through increased transcapillary escape of plasma) (14).…”

Infants' Blood Volume in a Controlled Trial of Placental Transfusion at Preterm Delivery

“…All of our infants had their lungs expanded through natural crying or facemask or endotracheal ventilation, as required to facilitate reduction of pulmonary vascular resistance and increase of pulmonary blood flow. 33 Placental transfusion may increase term and preterm infants' hematocrit and hemoglobin concentrations measured at 2 to 4 hours of age, 7,11,17 but some studies did not confirm this. 19,27 There was no significant difference in hematocrit levels between the DCC and ECC groups in our study.…”

Delayed Cord Clamping in Preterm Infants

“…Certainly the transfer of blood from placenta to infant in term infants is influenced strongly by respiration. [14][15][16] When the lungs expand, there is a large vascular bed into which blood may flow. Many of these very preterm infants require endotracheal intubation, not just stabilization.…”