Caesarean babies 'linked to asthma'

Babies born by caesarean section are more prone to developing childhood asthma, according to new research. The Dutch study of almost 3,000 children found that birth by caesarean was linked with an 80 per cent higher risk of developing the respiratory disease asthma by age eight compared with a natural birth. Children whose parents had allergies were even more likely to develop asthma, according to the study published in Thorax. The research has been used as fresh evidence to dissuade mothers from giving birth by caesarean section unless necessary.

Rates of childhood asthma have soared in industrialised countries in recent years.

Study leader Dr Caroline Roduit, now based at the Children's Hospital of Zurich, Switzerland, says the rate has risen in parallel with the Caesarean section births, which have increased from five per cent in the 1970s to more than 30 per cent in 2000.

She suggested that one reason for the increased risk could be the priming of the immune system after birth with a natural delivery as the baby is immediately exposed to microbes.

"The increased rate of caesarean section is partly due to maternal demand without medical reason," said Dr Roduit.

"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."