This is the first meta-analysis presenting evidence of the mortality benefit of KMC. We report a large cause-specific decrease of 51% (95% CI 18–71% reduction) in neonatal deaths with birth weight of <2000 g based on three RCTs (988 babies). A meta-analysis of three observational studies estimated a somewhat smaller effect (32% reduction), although these data are of lower quality and were in usual health system implementation settings. It is evident that KMC has a substantial mortality effect compared with conventional neonatal care, and it is also evident that this mortality benefit is possible even at large scale.27
Our analysis underestimates the overall health benefits as we did not include non-fatal outcomes or effects beyond the neonatal period. The Cochrane review for KMC assessed other outcomes in addition to mortality and morbidity including weight gain, breastfeeding and psycho-social outcomes such as bonding and maternal satisfaction and length of hospital stay. We have not reported on these here given our purpose of estimating mortality effects, but it is clear that there are other positive outcomes for the baby, mother and also the health system in terms of reduced work load for nurses and early discharge from hospital care.
This mortality estimate has a high evidence grade with the three RCTs from low and middle-income countries showing extremely consistent results, with only a slight reduction in quality as assessment was not blinded (). The meta-analysis of observational trials provides supportive evidence of a substantial mortality reduction, although largely driven by one large study using before and after audit data. We undertook two sensitivity analyses examining the exclusions made but still only applied for babies <2000 g. In both analysis significant evidence of large mortality effects remained (RR 0.60 and 0.62). However if all the normal birthweight babies in the Bangladesh community-based study were included, the uncertainty bounds were so wide that the result was no longer significant.
Quality assessment grade table of studies by outcome, as well as results from corresponding meta-analyses
There were several aspects of the studies we examined which mean that the mortality effect we have obtained may be an ‘underestimation’ of the benefit possible in many low-income settings (Box 1
). First, the control group in most studies was routine incubator care whereas currently for most of the more than one million neonatal deaths from preterm birth complications, there is often no medical care at all. Secondly, in the earlier trials there was a tendency towards later initiation of KMC with strict restrictions regarding age, weight or clinical status of babies. The practice now is to start KMC earlier as soon as the baby is clinically stable and this should result in a higher impact since the majority of neonatal deaths especially for small babies occur in the first few days of life. Finally, some of the studies only tracked pre-discharge mortality and did not cover the whole neonatal period, giving rise to the possibility of an under-estimation of post-discharge neonatal deaths. However there are also important potential biases that may result in an ‘overestimation’ of effect size, notably the selection basis for starting KMC in that only clinically stable preterm infants qualify to start KMC hence this effect size may not be reflect the reduction possible for all preterm deaths. Only one study specified a lower birth weight limit for starting KMC (1000 g).27
It may be that in settings with no medical care at all for the smallest babies, KMC may be better than nothing—this requires further evaluation.
Box 1 Cause specific mortality effect and quality grade of the estimate for the effect of facility-based KMC
Cause specific mortality to act on:
Preterm direct complications (within neonatal period)
Cause specific effect and range:
51% reduction (18–71%)
Quality of input evidence:
High (Three RCTS in low/middle-income countries), Mortality and morbidity data consistent
Observational data from large scale implementation trials are consistent
Proximity of the data to cause specific mortality effect:
High (cause specific mortality)
Limitations of the evidence:
Several systematic biases resulting in underestimation of mortality effect
- The control group in all these studies is routine incubator care, whereas the group of interest for policy/programmes are babies currently receiving no medical care
- Late initiation of KMC/strict restriction to older, stable babies, whereas practice now is to start KMC earlier. Early initiation of KMC for stable babies is likely to be higher impact since up to 50% of neonatal deaths occur on the first day of life
- Several studies track pre-discharge mortality only so some underestimation of neonatal mortality reduction
One important bias that may lead to over estimation is survival bias—the sickest babies may die before meeting criteria to commence KMC, or may not meet criteria of being clinically stable.
Where as this review establishes a clear and major impact on neonatal mortality, many questions remain around how to implement. Despite the high impact and apparent feasibility of KMC, few preterm babies in low-income countries currently have access to this intervention. No systematic data on global coverage are available. It appears that, in addition to Colombia, a number of countries in Latin America have made progress in scaling up KMC.17
In Asia there are many units now in Indonesia and some in India and Bangladesh but population coverage remains very low in these large countries. Within Africa, South Africa has multiple sites in almost every province27
and has employed a low cost model for lower levels in the health system which does not require special units. Malawi has a number of units but all at referral level.29
In most other African countries there are few if any units and these are mainly in capital cities and their presence has depended heavily on local champions to overcome initial resistance. A few countries notably Malawi,29
Tanzania and Ghana now have plans in place to scale up KMC to district hospital or even health centre level. To inform this process it is crucial to understand the constraints to scale up. These constraints may be due to lack of information about effectiveness, or is there reluctance to change current practice even if there are multiple babies per incubator, or perhaps a lack of trust in mothers and letting them onto neonatal units? Is KMC seen as a ‘poor country only’ solution? Formative work around these constraints as well as analyses of cost and potential cost savings on nursing time and length of in-patient stay are needed.
A priority research question concerns community KMC. There is only one study examining KMC initiation at home, in a challenging setting in rural Bangladesh.14
This study demonstrated a substantial mortality benefit for babies <2000 g (or modelled birth weight based on adjusted first weight after birth) but not for normal birthweight babies. At this stage, community initiation of KMC cannot be recommended based on the evidence from this one trial and larger trials in different settings are required. There are ethical concerns regarding increasing care for small babies at home without effective referral care as more babies will be identified who cannot be managed at home. It is important that KMC is not confused with routine skin-to-skin care alone, which is recommended at birth for all babies, whether in facility or at home, although the definitions for this practice and mortality effect data are lacking.
In addition there are no studies in low-income countries of KMC initiation at facility level with effective links to home after discharge. Given the inpatient stay of weeks or even months for very preterm babies, early discharge with effective links to the home would be of benefit to family and facility, but how would this work in practice in weaker health systems and is there a risk of increasing mortality post-discharge?