Updated: September 2019
The common practice of premature cord clamping has been challenged in recent years due to a greater understanding of how this intervention disrupts the physiology of placental transfusion (Mercer & Skovgaard 2002). Premature cord clamping results in hypovolemia (reduced blood volume) and is associated with poorer short-term and long-term outcomes (Kresch 2017):
- Short-term (first 24 hours): lower blood volume, lower systolic blood pressure, decreased renal flow, and decreased urine output ie. major organs are not optimally functioning.
- Long-term: lower serum ferritin levels and higher rates of iron deficiency anaemia at 6 months of age; and reduced fine motor function and social development at four years of age.
Awareness about ‘optimal cord clamping’ is increasing amongst parents and care providers (thanks to campaigns such as Wait for White). However, cord clamping during resuscitation is still an area of controversy. This post explores the the practice of premature cord clamping when a baby is perceived to need resuscitation. A recent study found that 29.1% of babies had their cord cut prematurely due to concerns for their wellbeing, either to obtain cord blood gases (13.4%), or to initiate resuscitation (15.7%) (Kearney et al. 2019). Whilst the rates of ‘concerns’ are very high in this study – the practice of cutting the cord in these circumstances is not surprising. In hospital-based newborn resuscitation workshops practitioners are taught to 1. assess the baby, 2. summon help 3. clamp and the cut cord, 4. take the baby to resuscitaire…. etc. However, this approach makes no sense if you consider the physiology of transition to extrauterine life, or the importance of the mother and the placenta in the baby’s transition and any necessary resuscitation.
The physiology of newborn transition
This is extremely complex and probably very boring for those not interested in science/physiology. If you want a full scientific version please see the article by Mercer and Skovgaard (2002). Here’s the simple version…
The baby/placenta has a separate blood system from the mother. The placenta does the job of the lungs by exchanging gas (oxygen and carbon dioxide) via the intervillous space between the baby’s and the mother’s blood system. Before birth, a third of the baby/placenta blood volume is in the placenta at any given time to facilitate this gas exchange. After birth the ‘placental’ blood volume is transferred through the pulsing cord into the baby increasing the baby’s circulating blood volume. This has two major effects:
- Provides the extra blood volume needed for the heart to direct 50% of it’s output to the lungs (8% before birth). This extra blood fills the capillaries in the lungs making them expand to provide support for the alveoli to open. It also aids lung fluid clearance from the alveoli. These changes allow the baby to breath effectively.
- Increases the number of circulating red blood cells which carry oxygen. This increases the baby’s capacity to send oxygen around the body.
The pattern and timing of the blood transfer from placenta to baby is influenced by a number of factors – in particular the baby’s breathing and/or crying (Boere et al. 2015). Textbooks and guidelines suggest the transfer takes 1-5 minutes, but some individual babies take longer. While the transfer takes place, oxygen continues to be provided by the placenta until the baby has established their breathing. Stem cells are also transferred into the baby during this time. There is a theory, and some evidence that these stem cells play an important role in repairing any damage caused during birth. They may actually protect against cerebral palsy! Dr Mercer discusses this in more detail here. You can read my opinion on ‘cord’ blood collection in this post.
A study found that healthy self-breathing newborns are more likely to die or be admitted to SCN if cord clamping occurs before or immediately after the onset of spontaneous breathing (Ersdal et al. 2014). However, most babies are able to compensate for their lack of blood volume by readjusting their circulation to direct their blood to their major organs. The effects of reduced blood volume will be subtle but present (and long-term). If you get a chance to hear Karen Strange speak about neonatal transition to extrauterine life – take it. She shows photos of the heel capillaries of a baby who has had premature cord clamping compared to a baby who has not. The small blood capillaries are collapsed – they have shut down in order to send the reduced blood volume to the important organs.
Reasons for resuscitating a baby at birth
There are two reasons that caregivers decide to prematurely cut a cord in order to resuscitate a baby. In both cases this action creates difficulties for the baby. In the first it can actually create the need to resuscitate.
1. Lack of knowledge, patience (and a bit of panic)
This often happens when a baby is slower to initiate breathing. The baby is still being oxygenated by the placenta but is waiting while the effects of an increased blood volume kick in. This is particularly common with waterbirth babies. These babies have good tone and slowly turn from bluish to pink. It can be difficult to even notice them begin to breathe. Their colour change may be the only obvious indication that they are making the transition. The cord pulses at the same rate as the baby’s heart, so feeling (or watching) it will reassure you that all is well. Unfortunately the usual response to this situation is to clamp and cut the cord in order to resuscitate the baby. The likely outcome will be that the baby responds to the interruption of placental flow and the stressful journey away from mother by crying. A worse outcome is that without the placental circulation the baby is unable to complete their transition and becomes a compromised baby requiring resuscitation.
2. A compromised baby
This is a baby who has had a rough time during birth and might require a little external support to make the transition. This situation is often a result of interventions during birth such as directed pushing, artificial rupture of membranes, syntocinon/pitocin. It may also be a result of a tight nuchal cord reducing blood flow just before birth (a loose one does not do this). A compromised baby is floppy and a blue/white colour. They may also have passed meconium during the birth, and their heart rate is slow and/or dropping. This baby could probably do with a bit of help, but most importantly they need their placental circulation. While the cord is intact the baby is still receiving some oxygen, which is better than none. In addition, the extra blood volume and red blood cells will help to circulate any oxygen the baby gets via resuscitation. You can see a very compromised baby being resuscitation with ongoing placental circulation in this movie:
Here is another film of Rixa Freeze’s unplanned unassisted birth where she resuscitates her own baby. You can read the full birth story and see part 1 on her blog. Rixa had learned newborn resuscitation:
Woman-centred, baby-centred, evidence-based resuscitation
Involvement of the mother and family
It is important that the mother, her partner and/or family members are involved in the resuscitation of a compromised baby.
For Baby: The baby has spent months inside their mother and learned her voice and smell. The baby has also learned the voice of those close to the mother ie. partner and/or other family members. To be held close, spoken to and stroked is often enough to initiate breathing. Even if further measures are needed, being held skin-to-skin with mother is less stressful than being put on a resuscitaire.
For mother and other family members: Being able to see and touch your baby is important in minimising stress. Assisting with the baby’s transition reinforces the power of the parents rather than that of the care provider. Seeing what is happening is less stressful than ‘not knowing’ what is going on. In addition, mothers often instinctively know how to help their baby. I remember one mother telling me she felt her baby needed to be in a certain position on her chest. When she moved him his breathing regulated perfectly.
Practical suggestions for resuscitation
Research is beginning to emerge in support of physiology and common sense. A recent randomised controlled trial concluded that resuscitation with an intact umbilical cord results in improved oxygen saturations and higher Apgar scores, with no negative consequences (Andersson et al. 2019). The discussion section of this article also cites research demonstrating that an intact cord improves resuscitation and reduces post-resuscitation complications.
However, most guidelines (and care providers) continue to recommend premature cord clamping for resuscitation. In contrast to most guidelines, WHO guidance on ‘delayed cord clamping’ state that “if the clinician has experience in providing effective positive-pressure ventilation without cutting the cord, ventilation can be initiated at the perineum with the cord intact to allow for delayed cord clamping.” Unfortunately this is contradicted in the WHO guidelines on resuscitation of the newborn which state that “the cord should be clamped and cut to allow effective ventilation to be performed.” As usual it will likely take many years to change a practice that was initially implemented without evidence.
Care providers often tell me they are unable to perform resuscitation without cutting the cord in a hospital setting because of how the equipment is set up (ie. fixed to a wall). However, paramedics in Queensland now resuscitate newborns without cutting their umbilical cord. If paramedics can do this in less than ideal settings, why can’t hospital staff? Hospitals need to start making equipment/staff fit around the needs of the baby and mother – not the other way around.
Another issue care providers bring up is blood gas analysis. This procedure is carried out if the baby has shown signs of distress during or immediately after birth (although some hospitals do this routinely!). It involves taking a small sample of the baby’s blood from the umbilical cord to measure the pH and other elements to determine if the baby was/is hypoxic. This is largely for litigation purposes – it does not alter the care of the baby or the outcome. Many care providers are under the impression that taking this sample requires cord clamping. This results in carrying out an intervention (clamping) known to compromise a baby, so that you can do a test to see how compromised that baby is – which is nonsense. However… if you really want to take a blood sample clamping is unnecessary.
“Sampling of cord blood for gas analysis may be performed on the unclamped cord right after birth without reducing the accuracy of the analysis.” (Thomasso et al. 2014)
I think that the next evolution of newborn resuscitation will be based around working with the placental circulation; and the following is my suggested approach to resuscitation – regardless of setting:
- Try and ensure that the baby does not arrive compromised by minimising unnecessary interventions.
- Do not clamp or cut the cord.
- Give the baby time to transition – if the cord is pulsing the placenta is providing oxygen… relax and reassure the mother if she needs reassurance. Keep observing the baby for signs of circulation and respiration.
- Do not clamp or cut the cord.
- If the baby requires assistance, start small – gentle stimulation, talking, blowing in their face (all can be done by a parent).
- Do not clamp or cut the cord.
- If further measures are needed, take the resuscitation equipment to the baby and resuscitate them in their mother’s arms.
- Did I mention – Do not clamp or cut the cord.
Note: Routine suctioning of the baby is totally unnecessary, invasive and could potentially create problems by stimulating a vagal response (a drop in the heart rate).
Babies are born with their own resuscitation equipment. The placenta not only helps the baby to transition, but assists with resuscitation if needed. There is no reason to clamp and cut the cord of a baby who needs help. Doing so will create more problems for the baby and mother. Anything that needs to be done can be done with back-up from the placenta, and the involvement of the mother.
- Mercer and Erickson-Owens (2014) – ‘Is it time to rethink management when resuscitation is needed?’ Journal article
- On Nuturing Hearts Birth Services’ website you can see a sequence of amazing photos taken of a cord after birth as it finished transferring blood.
- Nicholas Fogelson (Obstetrician) gives a very clear presentation of the research regarding premature clamping in a lecture. The ethics of the research is questionable but hopefully the findings will help to inform a change in practice.
- Very interesting and thought provoking interview with Dr Mercer