Scientists have developed a new method to estimate a newborn's gestational age just using a drop of blood, an advance that may help improve medical care for babies in developing countries.
Knowing if an infant was born on time or prematurely can make all the difference in deciding what medical care the baby needs, researchers said.
In developing countries, scarcity of technology, inadequate prenatal care and lack of early ultrasounds leave little more than birth weight to determine a newborn's gestational age.
Researchers at the University of Iowa in US have found that a metabolic profile derived from routine newborn screenings is a reliable method of estimating an infant's gestational age. All it takes is a drop of blood.
"It's important to know whether a baby is small because it is simply small in size but born on time or is small because it was born early," said lead author Kelli Ryckman, assistant professor of the UI College of Public Health.
"It helps determine how doctors should move forward with that baby and what kinds of health issues they should watch for," said Ryckman.
Premature - also known as preterm - birth refers to when a baby is born before 37 weeks of pregnancy.
According to the World Health Organisation (WHO), about 15 million babies are born preterm each year; that is more than 1 in 10 babies worldwide. Some 60 per cent of them are born in sub-Saharan Africa and South Asia, the researchers said.
The study analysed five years of data - about 300,000 records - from the Iowa neonatal newborn-screening programme.
The screening is a routine part of care for every baby born in the US and tests for mostly rare conditions that, if caught early, can be treated to reduce the likely damaging health effects to the child.
The researchers found metabolic markers measured during the newborn screening could build a first-ever metabolic gestational-dating algorithm, that could be used at the time of birth when there is no early ultrasound.
Researchers will conduct a metabolic-testing trial on 800 newborns in Uganda and Malawi. They will also apply a similar model to samples of the mothers' blood to see if they can determine which mothers may deliver early.
According to the WHO, in low-income settings, half of babies born at or earlier than 32 weeks die because of a lack of cost-effective care, such as warmth, breastfeeding support, and basic care for infections and breathing difficulties.
The researchers hope their metabolic gestational-dating algorithm can be used in developing countries to actively examine the rates of preterm births and then target at-risk areas with interventions and prevention programmes.
The study was published in the American Journal of Obstetrics and Gynecology.
