Hot debate about cool babies: Neonatal Encephalopathy’s tricky definition
Dr Shabina Ariff of AKU represents Pakistan in group trying to achieve consensus
It is rare for Paediatricians to fight like Linguists. But in the case of “Neonatal Encephalopathy” or newborn baby brain damage, a global debate is being duked out—politely and academically—on the haloed pages of eminent journals such as Nature.
The question: Are the medical mouthfuls ‘Neonatal Encephalopathy’ and ‘Hypoxic–Ischemic Encephalopathy’ interchangeable? One group of researchers, including Dr Shabina Ariff from Aga Khan University, believe they are not. They argue that HIE is a subset of NE and not the same thing. If we use these terms interchangeably we confuse families and stymie agreements on diagnosis and treatment.
But first, what is Neonatal Encephalopathy? Neonates are newborn babies. Encephalopathy means ‘brain injury’. As you may have heard, if a baby does not get enough oxygen, their brain can be damaged.
A timeline of the Paediatric Research, Nature published articles:
A newborn baby with Neonatal Encephalopathy (NE) becomes lethargic and comatose. “So, you have a floppy baby who is breathing well with a normal heart rate but is sluggish and shows no response like a normal, active, vigorous baby,” explains Dr Shabina Ariff. “The baby becomes lethargic because their brain has been affected.”
The brain is affected by oxygen starvation (hypoxia). When not enough oxygen goes to the brain when a baby is being born, it is called birth asphyxia as well.
This can happen in, for example, obstructed labor, if the baby is not in the correct position, or is lying sideways. If the healthcare provider does not catch this and perform a C-section, then the baby is put at risk of hypoxia. Hypoxia can lead to neurodevelopmental delay, cerebral palsy.
Sometimes, when a baby is being born, the placenta may fall off, which is known as abruption. Suddenly the baby loses its blood supply and contact with the mother. As a result, no oxygen flows into its blood and the baby suffers hypoxia. When the baby is born, it is limp and we need to resuscitate it.
Any trauma around the perinatal period (during pregnancy and a year after giving birth) can lead to NE (metabolic conditions, strokes, or any condition in the mother such as in utero infections).
In Pakistan, hypoxic injury or birth asphyxia is one of the three major causes of death in newborn babies. (The other two are sepsis and being born premature.)
Can doctors intervene to treat NE?
Over the years, scientists have tried to come up with ways or interventions to improve babies with NE, no matter why they developed it. They compared interventions to the usual standard and found that therapeutic hypothermia or cooling seems to work the best.
But there are few conditions. In therapeutic hypothermia, the body is cooled and then brought back to its normal temperature within 72 hours of birth. This has to be done within the first six hours of the brain injury if you want the maximum effect. And you have to be sure from their history that the baby has indeed suffered hypoxic injury to qualify for the treatment.
Unfortunately, the research trials have had very different outcomes for the same treatment. The problem is that different scientists have taken different outcomes. Some were looking at deaths being reduced. Others were looking at better neurodevelopmental conditions or better cognitive skills.
“Because we can't compare and the outcomes are not similar, this research is going to waste,” says Dr Shabina Ariff. AKU then collaborated with the University of Ireland to form the Cohesion Group to come up with a core set of outcomes in babies who develop NE.
Compared to sepsis and prematurity, there is still a lot that we do not know about NE. Because we know very little, it is difficult for scientists to agree on one definition. There is also a lack of agreement on how we should define NE and hypoxic ischemic encephalopathy. The COHESION Group is, therefore, trying to reach consensus on what should be labeled Neonatal Encephalopathy.
COHESION realized that when the group looked at the literature, the outcomes mentioned were not the same even if the intervention was the same.
“We felt the need—as neonatologists, scientists, research specialists—to come together with evidence and then share it with the global academia,” she says. “We published what we found in Nature and received a strong response. However, one critique was that they wanted us to change the terminology of ‘Neonatal Encephalopathy’ to ‘hypoxic ischemic encephalopathy’.”
“We feel that there's a significant heterogeneity (diversity) in the etiology (causes) of encephalopathy,” says Dr Shabina Ariff. “We do not have enough evidence to call it hypoxic ischemic encephalopathy. We have not done molecular studies, genetic testing on the mothers. We have not tested the fetal amniotic fluid…”
