Does cord drainage of placental blood facilitate delivery of the placenta?

Abstract

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 unclamped 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 fetomaternal transfusion rate. The well known association of prolonged duration of stage 3 of labour and the risk of haemorrhage was strongly confirmed.