"For example, at 35 weeks a baby’s brain weighs only two-thirds of what it will weigh at 40 weeks."
The research reveals babies born early are more likely to:
need help with their breathing
be admitted to a neonatal intensive care unit
spend longer in hospital; and
be readmitted to hospital in the first year of life.
"And in the longer term, early births are linked to an increased risk of developmental problems, such as poorer school performance," Prof Morris said.
"If a woman has a healthy pregnancy and there is no clinical need for earlier delivery, waiting until approximately 39 weeks is best for baby.
"This is in line with recommendations from the Royal Australian and New Zealand College of Obstetricians and Gynaecologists."