Blood test could pinpoint cause of brain injury in newborn babies – study

A blood test could pinpoint the cause of brain injury in newborn babies, and help identify the best treatment for them, a new study suggests.

The research looked at babies with a type of brain injury caused by hypoxia – a lack of oxygen.

It found that signals which are detectable in the blood can point to the cause of the injury and tell doctors if the baby is likely to respond to cooling treatment – commonly used to treat brain injury.

The findings could eventually lead to a simple test to quickly diagnose brain injury in newborns and help with treatment decisions, the Imperial College London researchers suggested.

The study included babies from low and middle-income countries (LMICs) as well as high-income countries (HICs).

It found a notable difference in gene expression – the process by which specific genes are activated to produce a required protein – between the two groups, suggesting a different underlying cause of brain injury.

According to the researchers, the findings indicate that newborn brain injury in poorer countries could be a result of multiple factors such as poor nutrition or infection.

While in wealthier countries, it was more likely to be a single cause such as complications during birth.

Lead investigator Professor Sudhin Thayyil from the department of brain sciences at Imperial said: “The gene expression patterns we saw in babies from LMICs were similar to what you would see in people with sleep apnoea, suggesting that they experienced intermittent hypoxia in the womb and at birth.

“We believe this is brought on by multiple chronic stresses during pregnancy such as poor nutrition or infection, as well as the normal labour process and uterine contractions, which leads to further hypoxia and ultimately injury to the baby’s brain.

“On the other hand, gene expression patterns in babies from HICs suggested a single, acute cause of brain injury, for example complications during birth like maternal bleeding, leading to a sudden drop in blood oxygen levels in the foetus.”

Professor Thayyil added: “The key for clinicians, anywhere in the world, is to be able to identify which type of brain injury they are dealing with as soon as possible – and that’s something we’re currently working on.”

Hypoxic-Ischemic Encephalopathy (HIE) is a type of brain injury sometimes referred to as birth asphyxia, which occurs when a baby’s brain does not get enough oxygen before or shortly after birth.

Experts say that across the world it is a leading cause of death and disabilities – including cerebral palsy, epilepsy, deafness or blindness – among babies born at full-term, affecting around three million babies every year.

South Asia, and particularly India, has the most cases in the world.

Previous research in low and middle-income countries suggested that whole-body cooling, which is used to treat the condition, actually worsened the condition in babies with HIE and might have even increased the risk of death.

The new study helps explain why there is a difference in response between the two groups of babies.

The research, led by Imperial and its South Asian partners, included 35 babies born with HIE in Italy (a HIC), and 99 babies from LMICs in South Asia (India, Sri Lanka and Bangladesh).

Blood samples were taken shortly after birth and the babies were assessed at 18 months of age.

Around half the babies in the South Asian group died or developed severe disabilities, while a quarter died or developed severe disabilities in the Italian group.

Study co-author Professor Swati Manerkar, from Lokmanya Tilak Municipal Medical College in Mumbai, India, said: “We were expecting to see some differences in gene expression between babies in the cohorts – but not such a dramatic divergence.

“It clearly shows that what we are seeing are very different causes of brain injury between the two groups, with different characteristics, which also helps to explain why some babies respond to cooling and others are harmed by it.”

The researchers stressed that the differences were not related to ethnicity, but rather socioeconomic factors.

The findings are published in the journal JAMA Network Open.