Why do obstetricians and midwives still rush to clamp the cord?BMJ 2010; 341 doi: http://dx.doi.org/10.1136/bmj.c5447 (Published 11 November 2010) Cite this as: BMJ 2010;341:c5447
- David J R Hutchon, retired consultant obstetrician, Darlington
In 2007 an editorial by Andrew Weeks advised that it was better for the baby not to rush to clamp and cut the cord at birth (BMJ 2007;335:312, doi:10.1136/bmj.39282.440787.80). He believed that it was time for us to follow the World Health Organization and the International Federation of Gynecology and Obstetrics and that other guidelines should remove the need for early cord clamping as part of active management of the third stage of labour. In the three years since this editorial there has been no significant change in practice and no change in the guidelines of the UK National Institute for Health and Clinical Excellence (NICE). Why are obstetricians so reluctant to change?
All mammals must transfer from placental to pulmonary respiration at birth; and, as with all our functions, Darwinian principles have ensured that this can usually occur without outside intervention. Transition involves ventilation of the lungs, which opens the pulmonary circulation, and this is followed by closure of the placental circulation. During these first few minutes the neonate remains at roughly the level of the placenta. In nature no clamp is involved, and constriction of the arteries (followed by the veins) is caused by vasospasm.
I have always argued that applying a clamp to the cord is clearly an intervention, having the greatest effect when it is done quickly after birth. Cord clamping has become the accepted norm so much so that delayed clamping is generally considered a new or unproved intervention. Thus, showing that immediate or early cord clamping offers no advantage to the baby is not enough; it has to be proved beyond reasonable doubt that it is harmful. Other interventions such as routine episiotomy were quickly abandoned when it was shown that they gave no advantage.
Could our basic teaching of physiology be a factor? Most textbooks with physiological descriptions of transition at birth state or imply that the cord circulation closes because of the application of the cord clamp. (Gray’s Anatomy is an exception.) Physiology is a description of the normal functioning of the body. Whether or not the timing of cord clamping has any effect on the health of the baby or the mother is irrelevant as to what constitutes a true physiological description. Such a distorted teaching of “physiology” may well account for the entrenched belief that delayed cord clamping is the intervention and may explain the apparent resistance of clinicians to follow the evidence.
The messages are mixed, and information is inconsistent. The Royal College of Obstetricians and Gynaecologists’ scientific advisory committee advised that there was no evidence that the timing of cord clamping affected postpartum bleeding yet still includes early cord clamping in its Green-top Guideline 52 (www.rcog.org.uk/files/rcog-corp/Green-top52PostpartumHaemorrhage.pdf). Michael Weindling, in a recent article in the Archives of Disease in Childhood (Fetal and Neonatal Edition) (2010;95:F59-63, doi:10.1136/adc.2006.115063), puzzled over the failure of paediatricians to act on the evidence for the benefit of delayed cord clamping; and James Neilson, in a recent BMJ editorial, said that delayed clamping should be practised (BMJ 2010;340:c1720, doi:10.1136/bmj.c1720). The UK Resuscitation Council’s Newborn Life Support: Provider Course Manual states in chapter 4 that “the cord can usually be clamped about a minute after birth, the baby being kept at approximately the same level as the mother’s uterus until this time.” The same paragraph warns that very early clamping and clamping while the baby is held above the level of the placenta can cause hypovolaemia. This recommendation has been reinforced by changes in the latest guideline from the council (www.resus.org.uk/pages/nls.pdf). Two popular pregnancy information books, The Day-by-Day Pregnancy Book by Maggie Blott and Your Pregnancy Week by Week by Lesley Regan, both describe delayed cord clamping as the norm and explain the advantage to the baby of delayed clamping.
Yet NICE’s guideline on intrapartum care, a powerful influence on practice, still advises early cord clamping as part of the active management of the third stage of labour (www.nice.org.uk/nicemedia/live/11837/36275/36275.pdf). If the need for early cord clamping was removed as an element of active management of the third stage of labour from this guideline, and its removal was publicised, there could be an overnight change in practice so, at least, we would have equipoise in the research question about the timing of cord clamping.
More research is needed. We need to know how delayed cord clamping can be incorporated effectively into neonatal resuscitation. This is likely to require technological developments in resuscitation equipment to allow the paediatrician to access the baby while it remains close to the perineum. How can we safely incorporate resuscitation during caesarean section? We need to know whether there are any situations, such as bleeding from vasa praevia, where clamping the cord may be beneficial to the baby. We need to know how to extract the maximum amount of the blood remaining in the placenta after delayed clamping to be available for cord blood banking. Observational research is not possible until the timing of cord clamping is routinely recorded.
Clamping the functioning umbilical cord at birth is an unproved intervention. Lack of awareness of current evidence, pragmatism, and conflicting guidelines are all preventing change. To prevent further injury to babies we would be better to rush to change.
Cite this as: BMJ 2010;341:c5447
Competing interests: DJRH organised a meeting, hosted at Worcester Royal Infirmary by Andrew Gallagher, to discuss how resuscitation with the cord intact could be initiated at the different modes of delivery, spontaneous delivery, assisted vaginal delivery, and caesarean section. This meeting coined the acronym BASICS to describe the concepts of a trolley that could be developed to provide the resuscitation equipment. DJRH and others at the meeting signed up to ownership of this intellectual property, but DJRH doesn’t expect any financial or other gain from this ownership.