WOMEN who choose to give birth by Caesarean section should be warned it could almost double their baby's chance of developing asthma, researchers said today.
Surgical deliveries alter the way the immune system develops by delaying exposure to gut bacteria, making infants more vulnerable to allergies.
A study of 2,917 births found Caesarean section babies were nearly 80 per cent more likely to be diagno
sed with asthma. The risk almost trebled for those with two allergic parents, giving them a genetic predisposition to the condition.
Dr Caroline Roduit, of the University Children's Hospital, Zurich, said: "The increased rate of Caesarean section is partly due to maternal demand without medical reason. In this situation, the mother should be informed of the risk of asthma for her child, especially when the parents have a history of allergy or asthma."
Her team monitored the respiratory health of the children until age eight, by which time 362 were asthmatic and prescribed inhaled steroids.
Even though only 247 (8.5 per cent) of the children had been born by Caesarean section, they were 79 per cent more likely to have asthma.
Latest figures show 23 per cent of all babies delivered in Britain's hospitals in 2005-6 were by C-section – more than twice the figure 15 years ago.
