Life preserver, early babies are extra vulnerable to cold (Image: Eric Fefeberg/AFP/Getty Images)

The tide is turning on child mortality. For the first time, infectious diseases like measles, malaria and diarrhoea are no longer the leading killers of young children around the world. That position is now taken by complications resulting from premature birth, a problem for both wealthy and low-income countries.

While deaths from infectious diseases have been steadily declining as a result of research and medical intervention, preterm birth has remained a much more difficult problem, say the authors of a recent study that collated child mortality rates and their associated causes between 2000 and 2013. For the purposes of their research, preterm birth was defined as any child born at less than 32 weeks.

Of the 6.3 million children around the world who died before the age of 5 last year, 1.1 million died from complications associated with being born early. This was more than those who lost their lives to any single infectious disease. The next biggest killers were pneumonia, complications during delivery such as a lack of oxygen and congenital abnormalities. Taken together, the number of deaths from all infections is still higher than the combined number of neonatal problems, but only by 6 per cent. “This really marks a tipping point,” says Joy Lawn, a perinatal epidemiologist at the London School of Hygiene and Tropical Medicine, who was part of the team that collated the data. “It shows where people have invested.”


The countries where the highest numbers of children die this way each year were India, Nigeria, Pakistan, Democratic Republic of the Congo, and China.

Back to basics

Preterm birth complications are a problem worldwide but the causes are different, as are the ways the problem will likely be tackled.

“One of the main messages here is that, particularly in low-income countries, preterm babies are dying of very simple things: being too cold, not being able to suck or not feeding properly,” says Lawn. “These are things that don’t necessarily involve machines and intensive care.”

So the emphasis in poorer countries needs to be on improving basic treatments that can have a big impact. Simple measures like improved feeding, infection prevention and antibiotics could go a long way to reducing these neonatal deaths, says Lawn.

In more developed nations, doctors are trying to prevent babies being born early in the first place. Contributing factors include women giving birth later in life, high blood pressure, obesity, smoking and the increased rates of elective caesarean sections which can result in preterm birth if there is ambiguity about the date of conception. But Lawn estimates that these factors only account for half the picture in developed countries, and even less in low-income countries.

Mysterious phenomenon

“Probably the biggest research gap is actually for the places where preterm birth is highest, which is southern Africa, but where the risks are different – there we have almost no C-section, no smoking, no big problems with diabetes and obesity,” she says. “There are actually things that we might be able to do more about, but there’s very little research into them.”

And that’s the problem. We know very little about what triggers full term labour, let alone preterm. Since last year, over $250 million in funding has been announced to investigate the causes of preterm birth. But Lawn points out that all of the initiatives are US-based, and over half the funding is coming from the Bill & Melinda Gates Foundation alone. If the research is going to have any real global impact, it will have to look beyond the causes and measures required in wealthy nations like the US, she says.

“There are some aspects of childhood death that are quite easy to reduce if you have the interventions: things like pneumonia, malaria, and diarrhoea,” says Cesar Victora, an epidemiologist at the Federal University of Pelotas in Rio Grande do Sul, Brazil. “But preterm birth is very complex – it’s not one disease. That makes it harder to prevent. I think a lot of people have not realised how big this problem really is until now.”

Journal reference: The Lancet, DOI: 10.1016/S0140-6736(14)61698-6