The third stage of labour begins immediately after the birth of the baby and ends with the expulsion of the placenta and fetal membranes. It is preceded by contraction and retraction of the uterus to reduce uterine size and expel the placenta with minimal haemorrhage. The third stage of labour can be managed actively or by expectant management, where the umbilical cord remains attached to the baby until after delivery of the placenta; blood within the placental compartment drains into the baby. Placental cord drainage involves clamping and cutting of the umbilical cord after the birth of a baby and then, immediately unclamping the maternal side of the cord so the blood can drain freely into a container. This may or may not, be used together with other interventions such as routine administration of an oxytocic drug (to contract the womb), controlled cord traction (applying traction to the cord with counter-pressure on the womb to deliver the placenta) or maternal effort.
This review included three studies involving 1257 birthing women. The findings showed that placental cord drainage in the management of third stage of labour reduced the length of third stage of labour by a mean of about three minutes and reduced blood loss by average of 77 ml. There was no clear difference in the manual removal of placenta or the risk of postpartum haemorrhage or incidence of blood transfusion. The trials did not report on maternal pain or discomfort during the third stage of labour. Some of the outcomes were not reported in the same way in all trials, limiting the amount of information available for analysis. Other desired outcomes were either not reported or were not reported in an appropriate way for statistical analysis (e.g. placenta not delivered within 30 minutes after birth, maternal haemoglobin changes). Further investigation of the effect of placental cord drainage on maternal outcomes would be useful although it is not a priority area for maternity research.
阅读完整摘要
Cord drainage in the third stage of labour involves unclamping the previously clamped and divided umbilical cord and allowing the blood from the placenta to drain freely into an appropriate receptacle.
研究目的
The objective of this review was to assess the specific effects of placental cord drainage on the third stage of labour following vaginal birth, with or without prophylactic use of uterotonics in the management of the third stage of labour.
检索策略
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (February 2010).
纳入排除标准
Randomised controlled trials comparing placental cord draining with no placental cord drainage as part of the management of the third stage of labour.
资料收集与分析
Two review authors independently assessed the quality of trials and extracted data. This was then verified by the third review author who then entered the agreed outcomes to the review.
主要结果
Three studies involving 1257 women met our inclusion criteria. Cord drainage reduced the length of the third stage of labour (mean difference (MD) -2.85 minutes, 95% confidence interval (CI) -4.04 to -1.66; three trials, 1257 women (heterogeneity: T² = 0.87; Chi²P=17.19, I² = 88%)) and reduced the average amount of blood loss (MD -77.00 ml, 95% CI -113.73 to -40.27; one trial, 200 women).
No incidence of retained placenta at 30 minutes after birth was observed in the included studies, therefore, it was not possible to compare this outcome. The differences between the cord drainage and the control group were not statistically significant for postpartum haemorrhage or manual removal of the placenta. None of the included studies reported fetomaternal transfusion outcomes and there were no data relating to maternal pain or discomfort during the third stage of labour.
作者结论
There was a small reduction in the length of the third stage of labour and also in the amount of blood loss when cord drainage was applied compared with no cord drainage. The clinical importance of such observed statistically significant reductions, is open to debate. There is no clear difference in the need for manual removal of placenta, blood transfusion or the risk of postpartum haemorrhage. Due to small trials with medium risk of bias, the results should be interpreted with caution.
