Significant blood loss after birth is the most common cause of maternal death in the developed world, and is also a major cause of reduced post-natal health. Postpartum haemorrhage refers to the loss of more than 500 ml of blood following a vaginal delivery or 1000 ml of blood following a caesarean.
While in some cases, significant blood loss can be attributed to a known and high risk condition, such as placenta previa, there has been much debate about the factors which may contribute to the risk of significant blood loss in otherwise low risk births. Among these, both place of birth and the effect of medical interventions have perhaps been the most scrutinised.
A recent New Zealand-based study sought to determine whether place of birth impacts on the risk of significant bleeding after birth. The study examined data from 16,210 low-risk births in 2006 and 2007 taking place at home and in hospitals of varying sizes and specialities. But despite expectations to the contrary, the study established that place of birth appeared to have no impact on the risk of postpartum blood loss greater than 1000 ml.
However the study did make a startling discovery in relation to the role of intervention in blood loss. Of the low-risk births examined, more women experienced significant blood loss where active management of labour was employed. More specifically women experiencing active management of their third stage (the delivery of the placenta) experienced a twofold increase in the likelihood of blood loss greater than 1000 ml, over women expelling their placenta physiologically.
Active management of the third stage is defined as the use of drugs to stimulate separation of the placenta (such as Syntocinon), prompt clamping and cutting of the umbilical cord, and controlled cord traction (pulling off the umbilical cord to draw out the placenta). By comparison physiological management of the third stage avoids the use of drugs and cord traction, promotes delayed clamping and cutting of the cord, and places the focus on allowing the placenta to be birthed naturally through maternal effort (pushing).
While this statistic was not primarily influenced by place of birth, it is important to keep in mind that women birthing at home or in a birth unit are statistically more likely to choose a physiologically third stage. Oxytocin is important to the third stage of labour as it stimulates uterine contractions. A birth following a physiological labour, where skin-to-skin contact and breastfeeding is encouraged, floods a women’s body with Oxytocin. Anything which disrupts this delicate balance has the potential to significantly impact the outcome for mother and child.
A managed third stage is largely a managed third stage, no matter where it occurs, although some consideration perhaps needs to be given to the level of skill of caregivers. However the likelihood of a managed third stage increases along the scale from homebirth, to birth unit, to public hospital with the highest rates of intervention seen in the private health care system. As such, while place of birth may not affect the chance of postpartum haemorrhage, a women’s knowledge of available choices and her decisions in regards to a managed or physiological labour, birth and third stage would appear to impact greatly on the potential for significant blood loss.
Apart from the obvious risk of death as a result of postpartum haemorrhage, significant blood loss slows a women’s recovery after birth, can impact on her ability to breastfeed, and has the potential to create significant financial and emotional strain on families. Given the connection between intervention and blood loss, it is important that any intervention in labour and birth is carefully considered based on its value to mother and baby. It is important too that caregivers in all birth settings are well versed, skilled in supporting and proactive in recommending a physiological labour, birth and third stage in order to minimise the risk of postpartum haemorrhage.