P

remature birth is defined as birth before

37 completed weeks of gestation. It is now identi-

fied by the World Health Organisation as the

number one global killer of children under 5 years

of age, with a high prevalence in Australia (8%)

and even higher rates in many developing countries and the

US, where up to 12% of babies are preterm. Every year around

the world, 15 million babies are born prematurely and one

million of those will die.

The proportion of pregnancies ending prematurely is esca-

lating annually. Large cohort studies point to environmental

causes such as infection, pollution, poor diet, stress and socio-

economic status, but the underlying causes and the specific

factors accounting for this rise in prevalence are unknown.

Modern post-natal health care now enables the survival of

most preterm babies born after 32 weeks, but they are at higher

risk of developmental problems and complications. Infants

born early, especially those born less than 34 weeks gestation,

are prone to cerebral palsy, mental retardation, visual impair-

ment, hearing loss and less obvious central nervous system

disorders, including language and learning disabilities, attention-

deficit hyperactivity disorder and behavioural problems.

The average cost of neonatal care is estimated at more than

A$50,000 for each preterm infant. The life-long economic

health, psychological and social costs to the child, his family

and society are considerably higher.

The major culprit is spontaneous preterm labour, which is

often linked with bacterial or viral infection of the placental

membranes. However non-infectious insults such as multiple

pregnancy, blood supply issues to the placenta or immune

imbalance can also cause preterm labour. All of these causes

operate through a converging pathway leading to delivery.

JAN/FEB 2016|| 29

Born Too Soon

SARAH ROBERTSON & MARK HUTCHINSON

Each year a million babies die after premature birth, but researchers have now identified a

potential treatment.

MichaelDeLeoniStockphoto