WA researchers teach babies day from night

Rebecca Gredley

Whether health outcomes for premature babies can be improved by restoring their natural sleep-wake cycle, could be determined as part of a West Australian study.

Although a circadian rhythm only fully develops a few months after birth, it begins in-utero with information about the time of day passing from mother to baby late in the third trimester of pregnancy.

"In pre-term babies however, exposure to these important maternal circadian signals is cut short by the delivery of the baby," University of Western Australia reproductive biologist Peter Mark said.

"The babies' chances of establishing circadian rhythm are then further challenged by the continuous noise and bright lighting of the neonatal intensive care units into which they are invariably placed."

The researchers will teach pre-term babies day from night by putting them in regular light and dark periods, using tiny blindfolds and earmuffs to simulate night-time, and will also provide them with small doses of cortisol and melatonin, which regulates the circadian rhythm.

It will be seen if this can improve growth, enable earlier hospital discharge and enhance brain development.

It is well documented that people with disrupted circadian rhythms have an increased risk of obesity, cancer and disease, with shift-working mothers delivering higher rates of small babies at full-term than non-shiftworking mothers, Dr Mark says.

The study will use babies of between 28 weeks and 32 weeks gestation, with recruitment expected to begin at the end of the year.