Does Cord Drainage of Placental Blood Facilitate Delivery of the Placenta?

EDITORIAL COMMENT: Most busy practitioners hold strong opinions, based on clinical experience they will say, of the preferred regimen for management of common clinical problems. This study shows that strongly held beliefs may be falacious. The authors have shown that drainage of placental blood from the cord does not affect the rates of retained placenta and postpartum haemorrhage. The editor has always taught that releasing the cord clamp and allowing drainage of placental blood minimizes fetomatemal haemorrhage and assists placental delivery ‐ he stands corrected. However, draining the cord does no harm, and the reviewer of this paper commented that at least it minimizes the mess if the cord breaks during delivery of the placenta by controlled cord traction! Our common clinical regimes should be scrutinized more often, especially when clinical results or community costs are involved. This study did not attempt to assess the value to the fetus of early versus late clamping of the cord. However, the volume of cord blood drained by release of the clamp (mean 54ml; range 0–185ml) suggests that the practice of early versus late clamping of the cord should be reevaluated to assess the volume of blood denied to the infant and the clinical implications of withholding this blood infusion. Summary: A series of 1,908 women delivering vaginally, and actively managed in stage 3 of labour, were randomly assigned to 2 groups to study if cord drainage of placental blood facilitated delivery of the placenta. Prophylactic oxytocics were given with the birth of the anterior shoulder. In both groups, early cord clamping was practised, timing being at the midwives' discretion. In the control group the cord remained clamped; in the drainage group the cord was undamped and the volume of placental blood measured. Controlled cord traction completed active management at evidence of separation/descent of the placenta. Rates for retained placenta, postpartum haemorrhage and transfusion were similar. It was concluded that when the third stage of labour is actively managed, placental drainage of cord blood confers no extra benefits. Pre‐ and post‐delivery Kleihauer tests were performed on blood from 20 women in each group. All tests were negative. Contrary to previous work, this does not suggest that cord drainage reduces the fetomatemal transfusion rate. The well known association of prolonged duration of stage 3 of labour and the risk of haemorrhage was strongly confirmed.