Re: Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomised controlled trial
Concerning the level of the baby relative to the uterus, available research could be summarized to: if the child is held at 20 cm or more under the uterus, the complete transfusion is performed within one minute, at +/- 10 cm of the level of the uterus the transfusion will take about three minutes, at 20 cm above the uterus the transfusion will be decreased to finally be stopped at a level of 40 cm above the uterus. Placing the baby at the mothers abdomen directly will perhaps diminish the transfusion (se ref 3), but there don't seem to be a risk for reverse transfusion.
In our study (1), the children in both clamping groups were held at approx 20 cm under the introitus for 30 seconds, and were then transfered to the mothers chest or abdomen. That is, the delay to "skin-to-skin" was 30 second in both groups. During this 30 seconds the midwife checked the babys vitality and wiped the baby briefly before moving the baby to the mother. This method was designed in collaboration with the staff at the OB department, including both midwives and obstetricians.
The effects of gravity was studied by Yao and Lind (2), I quote the abstract:
"The effect of gravity on placental transfusion was studied by measuring the placental residual blood volume (P.R.B.V.) in one hundred and twelve normal deliveries with the infants kept at different levels above or below the mother's introitus after birth. The results demonstrated that hydrostatic pressure, brought about by keeping the infant 40 cm. below the introitus, hastened placental transfusion to almost completion at about 30 seconds. In the presence of this effect of gravity, prolonging the time of cord clamping to 3 minutes did not result in a significantly larger amount of placental transfusion. Whereas, the effect of hydrostatic pressure created by having the infants held above the level of the mother's introitus lessened or prevented placental transfusion by partially or completely obliterating the pressure generated by uterine contraction."
Nelle et al (3) compared early cord clamping with delayed cord clamping after delivery according to the Leboyer method (directly placing the baby on the mothers abdomen) and concluded that about 20 ml/kg of extra blood was suggested to be transfered from the placenta to the child.
1. Andersson O, Hellström-Westas L, Andersson D, Domellöf M. Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomised controlled trial. BMJ 201; 343: d7157. doi:10.1136/bmj.d7157
2. Yao AC, Lind J. Effect of gravity on placental transfusion. Lancet. 1969 Sep 6;2(7619):505-8
3. Nelle M, Zilow EP, Kraus M, Bastert G, Linderkamp O. The effect of Leboyer delivery on blood viscosity and other hemorheologic parameters in term neonates. Am J Obstet Gynecol. 1993 Jul;169(1):189-93.
Competing interests: No competing interests