World-first clinical trials have started in Victoria after Australian researchers discovered that melatonin, a naturally occurring hormone, may prevent brain injuries in unborn babies.
The injuries, which can be caused during pregnancy or labour, can lead to such conditions as intellectual disabilities, epilepsy, and learning and behavioural problems. It can also lead to cerebral palsy, which is the most common physical disability in childhood, with an Australian baby born with the condition every 15 hours.
The trials, being conducted at Southern Health’s Monash Medical Centre and The Ritchie Centre at the Monash Institute of Medical Research, are being offered to women carrying growth restricted babies, which occurs in approximately 1 in 20 pregnancies.
“Women are identified when they are seen clinically and thought to have a small baby on board,” says leading obstetrician and Director of the Ritchie Centre, Professor Euan Wallace. “They are then referred to us for an ultrasound scan. If this confirms a small baby then we offer the treatment.”
The cause of these brain injuries during pregnancy is an excess in free radicals, which leads to oxidative stress. For growth-restricted babies, Wallace says that the most common cause is a placenta that hasn’t developed properly, and therefore doesn’t provide the baby with enough oxygen.
If successful, the melatonin supplements are something that may become a routine part of pregnancy care
“This happens from the very beginning of pregnancy and is not usually related to anything the women has or has not done,” he explains.
Although melatonin is mostly known for regulating our body clock to assist with sleep, it is also a powerful natural antioxidant which is able to change the dangerous free radicals into a form that isn’t harmful to our bodies.
“We believe, based on our research to date, that melatonin prevents oxidative stress in the developing baby's brain at a critical stage of brain development or at the time of birth,” Wallace says.
Based on this research, the current trials involve expectant mothers taking melatonin tablets in order to provide the antioxidant to their unborn babies. Each pregnancy is then monitored carefully and cord blood and placenta is taken for testing after the birth of the baby. As the level of free radicals has shown to be higher in the umbilical cord blood in growth restricted babies, this will provide researchers with indicative results of the trials. Experiments have already been conducted with sheep, with the melatonin supplements successfully correcting the oxidative stress in foetal lambs.
In a linked study by the Ritchie Centre, research has indicated that melatonin can also prevent these brain injuries in babies who are asphyxiated during labour, most commonly caused by obstruction of the umbilical cord. This affects more than 1 million babies worldwide each year, even those whose mothers have the healthiest pregnancies.
In this case, the melatonin would be given directly to the baby shortly after birth. This study is still in the experimental phase, in which researchers have been administering the melatonin to newborn lambs for approximately the last 18 months, but Wallace says the team hopes to move to clinical trials with humans in 2013.
An added benefit to these trials is that they have also shown an improvement in the lambs’ ability to feed. This is due to the protection the melatonin gives the brain, which Wallace hopes will also be true in human babies.
Another advantage is that there are no adverse side effects, as melatonin is produced naturally by our bodies.
This ground-breaking research is a collaborative effort involving the work of scientists, obstetricians, paediatricians, radiologists, and midwives, work which Professor Wallace says is very exciting.
“It is hard work - trying to unravel the mysteries of human brain development, how this can go wrong and how we can prevent that. The thought of preventing even one child developing cerebral palsy is thrilling,” he says.
If successful, the melatonin supplements are something that may become a routine part of pregnancy care, the way that many women now take folic acid to help prevent spina bifida. If this is the case, however, Wallace says it is still further down the track as there is still so much to be learned.