Our culture’s prioritisation of biomedical models of health, outcome-focused research, and risk-based protocols has led to some curious anomalies of thinking. In systems of maternity care, intervention is sometimes deemed the default approach, and—even more astonishingly—the measure by which the value of physiological processes is assessed. In some situations in maternity care, natural processes and simple comfort measures have to be proven safe and beneficial, while interventions known to carry risk as well as benefit are readily accessible.
The need to prove safety can be problematic, because the very ideology that underpins scientific research makes safety very difficult to prove. But in one area of maternity care that has received a lot of attention over the past few years, an increasing volume of research is demonstrating that it is both safe and beneficial to wait. We are referring to the question of optimal cord clamping: being patient before rushing to cut the baby’s umbilical cord, unless there is a problem which necessitates a speedier approach. We gathered data on this area when we were updating our book, Birthing Your Placenta, and we are delighted to share some excerpts from the book with Midwifery Today readers (below) as evidence—should it be needed—of the value of patience and watchful waiting at this time.
Evidence of the Advantages of Patience
The transfer of the blood that has been circulating in the placenta in the moments after birth is the main reason that it is important to allow time before clamping and cutting the baby’s cord. Many practitioners are aware that the baby needs to be able to access its full complement of blood in order to support lung expansion and additional blood volume requirements from the placenta, which occur as the first breaths of air are taken. If the cord is clamped immediately at birth, blood from the placenta cannot flow through it and this blood therefore cannot be used to support the process of lung expansion and respiration. Blood then has to be “borrowed” from the rest of the baby’s circulation in order for its lungs to become fully functioning, even though the baby’s other vital organs also need blood to function fully and optimally (Mercer, Skovgaard, and Erickson-Owens 2008; Mercer and Erickson-Owens 2010).
We are only really beginning to discover the myriad reasons why babies need to be able to access their full complement of blood before we interfere with the supply by clamping and cutting the cord. Our knowledge of this area has increased fairly rapidly over the past few years, although we still have a lot to learn. In 1974, Yao and Lind found that when a baby received its full quota of blood it was better able to maintain its haematocrit levels (ratio of red blood cells to total volume of blood). In the past, commentators knew that this quota of blood was important (Inch 1983) but it is only more recently that we have come to understand the implications of early cord clamping more fully.
The research in this area has now become more widely known and incorporated into practice. A number of studies have shown that allowing the cord to remain intact for a period of time confers significant advantages to the baby (McDonald et al. 2013; Mercer and Erickson-Owens 2014; Hooper, Polglase, and te Pas 2015). Our current understanding is that allowing the cord to remain intact helps a baby to establish breathing and circulation, which is particularly advantageous for babies who are compromised or born prematurely (Mercer and Erickson-Owens 2010). Allowing the cord to remain intact can lead to a reduction in breathing difficulties and less need for supplemental oxygen, ventilation, and blood transfusion (Mercer 2001). Other benefits include an improvement in cardiac (heart) function (Bhatt et al. 2013; Hooper, Polglase, and te Pas 2015), an increase in the baby’s iron stores (Chaparro et al. 2006; Andersson et al. 2011), and neurological advantages (Hutchon and Wepster 2014).
We know that later cord clamping can lead to a baby receiving almost a billion more stem cells (which have healing qualities) than if the cord is clamped and cut early (Mercer and Erickson-Owens 2010). Later cord clamping can also reduce the likelihood of severe infection (also known as sepsis) in pre-term babies (Mercer and Erickson-Owens 2006; Mercer and Erickson-Owens 2010). Hutchon (2016) suggested that the intervention of immediate cord clamping may cause some babies to need to be resuscitated. Other studies show that babies whose cords are clamped earlier experience disadvantages. Mercer Skovgaard, and Erickson-Owens (2008) note that babies who experience immediate cord clamping are likely to have hypovolaemia (too little blood volume) and suggest that this can lead to the release of substances called inflammatory cytokines, which are associated with cerebral palsy.
While severing the baby’s blood supply quickly and suddenly can have notable effects on some full-term babies, the effects can be even more detrimental in babies who are premature (particularly if born by caesarean) or who are slow to breathe at birth (Mercer 2001; Mercer, Skovgaard, and Erickson-Owens 2008; Mercer and Erickson-Owens 2010, 2014). In addition to all the impacts of a reduced circulating blood volume, red blood cells, and stem cells that we have previously noted, preterm babies are more likely than full-term babies to need additional oxygen, ventilation, and blood transfusions and are more likely to suffer from intraventricular haemorrhage (a bleed in their brain), breathing difficulties, and sepsis.
Brocato et al. (2016) showed that premature babies have less chance of needing a blood transfusion or of having an intraventricular haemorrhage if they are given time to access their full complement of blood. A number of hospitals are now buying and using equipment which enables staff to provide additional help (resuscitation) to premature or compromised babies while they remain alongside their mothers with their umbilical cords intact.
These benefits are summarised in systematic reviews and acknowledged in reviews looking at the “management” of the birth of the placenta. In 2010, the Cochrane review comparing active management with physiological placental birth noted that about 20% of a baby’s blood volume is lost when the cord is clamped early (Begley et al. 2010). This is also acknowledged in reviews on cord clamping, for instance where McDonald et al. (2013) note Mercer’s (2001) revelation that “placental transfusion can provide the infant with an additional 30% more blood volume and up to 60% more red blood cells.” The benefits of higher iron stores are experienced for several months after birth, even if the cord remains intact for only one to three minutes after birth (McDonald et al. 2013). In both early and more recent studies, there is a bit of inconsistency in the actual amount of blood volume that babies are estimated to receive if the cord is left pulsating. We don’t know why this is, although it is possible that this is a normal and natural variation in what happens if babies’ bodies are allowed to determine their own needs.
The Social Benefits of Waiting
As we have seen, there are numerous physiological benefits of a more patient approach to cord clamping for healthy term babies, “with virtually no risk of harm to mother and baby” (Muza 2013).
Beyond the physical benefits of leaving the cord intact for a short while after birth, researchers have discussed the way in which early cord clamping leads to less “protected” time for the mother and her baby (Mercer and Erickson-Owens 2010). Some people feel that there are social and psychological advantages for the mother and baby having undisturbed time before the cord is clamped and cut. This undisturbed time can enhance the relationship which begins to develop between the mother, her baby, and her partner, if present. Any siblings or other family members present will also be meeting the baby for the first time.
The first hour or so after birth is a particularly awesome, miraculous, important, delicate, and intense time of transition for mother, baby, and family. If undisturbed, both mother and baby will continue to produce hormones that help them to form a strong, loving connection. This helps the woman to feel protective of her baby and, according to physiologist and midwife Verena Schmid (2005), it contributes to ongoing attachment patterns between mother and baby, between family and baby, and in the baby’s ongoing relationships as it moves through childhood into adulthood.
In a more relaxed setting where cord clamping and cutting are delayed, the mother and baby may be more likely to have skin-to-skin contact and the baby may nuzzle and begin to suckle at its mother’s breast. This improves the baby’s oxygen levels and lowers its heart rate (Mercer and Erickson-Owens 2010). Skin-to-skin cuddling also increases the flow of the hormone oxytocin, which helps the separation of the woman’s placenta and is the main hormone of love (which Foureur  notes was a term first used by Niles Newton) and bonding (Odent 1999; Schmid 2005). Babies nurtured this way have been shown to breastfeed for 10–12 days longer than those with early cord clamping (Mercer 2001).
Other Benefits of Waiting
A large systematic review found that healthy women who have a physiological birth of their placenta are less likely to experience afterpains, less likely to experience vomiting, less likely to need analgesia (pain relief) in the first hours after birth, and less likely to need to return to hospital because they are bleeding heavily in the days or weeks after birth. They are also less likely to have high blood pressure than women who had an actively managed third stage which includes uterotonics containing ergot compounds (Begley et al. 2015). Furthermore, the woman’s sense of confidence in her own body may be enhanced.
Some people have theorised that, particularly where a woman is having a physiological birth of her placenta, a more relaxed approach to cord clamping may also confer physical benefits in relation to the birth of the placenta itself. Dunn, Frazer, and Raper (1966) raised the possibility of the placenta being bulkier when fetal blood is prevented from passing to the baby. At the time of this research, it was suggested that early cord clamping might prolong placental separation due to fetal blood remaining in the placenta, which may delay contraction of the woman’s uterus. Botha (1968) suggested that clamping the maternal end of the cord may interfere with placental separation and predispose a woman to greater blood loss, an idea which was noted by Levy (1990) and Rogers and Wood (1999). To our knowledge, none of these ideas has ever been the main focus of research.
A few researchers have also speculated about the possibility of feto-maternal transfusion (mixing of the baby’s and mother’s blood) because of a larger volume of blood remaining in the placenta. One theory is that, as the uterus attempts to contract to expel the placenta, the pressure exerted can cause placental vessels to rupture, allowing fetal cells into the maternal system. This may be significant if the mother is Rhesus negative and her baby is positive (Ladipo 1972; Prendiville and Elbourne 1989; Wickham 2001). Rogers et al. (1998) considered this in their research but did not confirm an association.
Some of these ideas are fascinating, and it would be great to see them become the subject of studies in their own right. The sources of knowledge that we have cited here range from Cochrane Collaboration systematic reviews and meta-analyses to the careful sharing of individual professional expertise and wisdom. All of these sources of knowledge are valuable, even while some will be more readily accepted by proponents of the obstetric paradigm. What is important is that these ideas are being shared and that, in this area at least, the value of patience and the benefits of waiting are being accepted by proponents of the obstetric paradigm and within systems of maternity care. We can hope that this is the beginning of a wider acceptance of advantages of taking a position which is more respectful of physiology and less focused on the notion that there is anything to be gained from rushing in and interfering without good reason to do so.
Parts of this article have been excerpted from Birthing Your Placenta: the third stage of labour, authored by Nadine Edwards and Sara Wickham and published in 2018. More details about the book can be found at sarawickham.com/byp/.
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