A new study has found that very small babies delivered early, because they were not growing well in the womb, are at a higher risk of respiratory problems if they are delivered by caesarean section, versus induced vaginal delivery.

Johns Hopkins researchers looked at more than 2,500 small babies delivered between 25 and 34 weeks of pregnancy and found those delivered by c-section were 30 per cent more likely to develop respiratory distress syndrome.

The study’s lead author says this challenges conventional thinking that caesarean’s are less traumatic for extremely small babies.