Knowledge about the short-term and long-term benefits of ‘delayed cord clamping’ is finally making it into practice. Midwives and in some cases obstetricians are realising the importance of allowing the placenta to finish circulating blood before intervening. I personally don’t like the term ‘delayed cord clamping’ and prefer the term ‘premature clamping’ to describe the alternative practice. However, whatever you choose to call it, the good news is that babies are benefitting from the practice. The main physiological benefits are summed up in a Cochrane review:
“The suggested neonatal benefits associated with this increased placental transfusion include higher haemoglobin levels (Prendiville 1989), additional iron stores and less anaemia later in infancy (Chaparro 2006; WHO 1998b), higher red blood cell flow to vital organs, better cardiopulmonary adaptation, and increased duration of early breastfeeding (Mercer 2001; Mercer 2006). There is growing evidence that delaying cord clamping confers improved iron status in infants up to six months post birth (Chaparro 2006; Mercer 2006; van Rheenen 2004).”
The review also notes that ‘delayed clamping’ is associated with an increased risk of jaundice in the newborn. In contrast Mercer and Skovgaard (2002) cite research findings that dispute this link. I also wonder whether giving an injection of syntocinon/syntometrine while the placenta is still circulating blood to the baby may influence the risk of jaundice. IV syntocinon/pitocin in labour has been linked to jaundice since the 1974s (do a google search for more research). All the studies in the Cochrane review were carried out in hospitals where the vast majority of women have an oxytocic injection for management of the third stage. I very rarely come across anything more than mild jaundice following a physiological birth. Anyone need a research topic?
Resuscitation and premature cord clamping
This post explores the the practice of premature clamping when a baby is perceived to need resuscitation. I often hear birth stories which include “They (or I) had to cut the cord because the baby needed resuscitation”. In hospital-based neonatal 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. For obvious reasons resuscitating a baby is stressful, and I understand the benefits for midwives and doctors of doing it on a nice neat, ‘clean’ area without worried parents watching and/or asking questions. However, this approach makes no sense if you consider the physiology of transition to extrauterine life, or the importance of the mother 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. So, 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 this ‘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.
This transfer of blood volume from placenta to lungs takes place over a number of minutes following birth. Textbooks will tell you 3-7 minutes, but I have felt cords pulse for longer than that. While these changes take place, oxygen continues to be provided by the placenta until the baby is ready to begin breathing. Stem cells are also transferred into the baby during this time. There is a theory, and some evidence that these 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.
Most babies will initiate breathing quickly after birth and premature clamping of the cord will not have any immediately noticeably effects. The baby’s circulation will adjust to direct the smaller blood volume to the important organs. The effects of a reduced blood volume will be subtle but present (see the above Cochrane review).
The need for resuscitation
There are two reasons that caregivers decide to abandon ‘delayed cord clamping’ and clamp/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 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 chilling out 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 blue 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 outcome will be that 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 (see below).
This film is of an outdoor birth (the mother didn’t make it to her birth tent). The baby makes an unhurried transition supported by placenta circulation:
This baby is also able to make a gentle transition to breathing:
Whereas this baby is being hurried to cry (also see birth from the baby’s perspective)
2. A compromised baby
This is a baby who has had a rough time during birth and might appreciate 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 heading from a blue colour to a 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 into the lungs via external methods of resuscitation. You can see a very compromised baby being resuscitation with the placental circulation in this movie:
Here is another film of Rixa Freeze’s surprise unassisted birth where she resuscitates her own baby. You can read the full birth story and see part1 on her blog. Rixa had learned newborn resuscitation:
Here is a film of an unassisted birth where a mother instinctively resuscitates her own baby:
The importance of the mother and family in resuscitation
It is important that the mother, father or any other significant person is involved in the resuscitation of a compromised baby.
A baby has spent months inside his mother and learned her voice and smell. She has also learned the voice of her father 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 by her mother skin to skin, rather than being put on a flat resuscitaire has got to be nicer.
For mother, father and/or other family members
Being able to see and touch your baby is probably less stressful than having her ‘worked on’ over the other side of the room. Being involved in assisting the baby’s transition reinforces the power of the parents. Fathers are often very proud to be the one who encourages baby’s first breath by blowing gently in her face. 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.
- 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.
- Do not clamp or cut the cord.
- If the baby requires assistance, start small – gentle stimulation, talking, blowing in his face (all can be done by a parent).
- Do not clamp or cut the cord.
- Milk the cord firmly towards the baby. This shunt of blood into baby is often enough to initiate breathing.
- Do not clamp or cut the cord.
- If further measures are needed, take the resuscitation equipment to the baby and resuscitate him in his 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).
You can find some photos of a baby being resuscitated in his mother’s arms here.
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, Skovgaard and Erickson-Owens (2008) have written a great chapter about the transition from placental circulation to breathing in this book.
More information about the third stage of labour and ‘delayed cord clamping’ can be found in an online article by Sarah Buckley.
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
George M Morley has a written a very in-depth article about the physiology of neonatal transition to breathing, and resuscitation.
This post is also available in French here.