Babies delivered by Caesarean section have a 20 percent higher risk than normal deliveries of developing type 1 diabetes in childhood, according to a study by a team of researchers from  Queen's University Belfast

The team, led by Dr. Chris Cardwell and Dr. Chris Patterson, examined 20 published studies from 16 countries, including around 10,000 children with type 1 diabetes and over a million control children.

In children born by Caesarean section, they found a 20 per cent increase in the risk of developing the disease. The increase could not be explained by birth weight, the age of the mother, order of birth, gestational diabetes in the mother, or whether the baby was breast-fed or not, all factors associated with childhood diabetes in previous studies.

Dr Cardwell, from the School of Medicine, Dentistry and Biomedical Sciences, said: "This study revealed a consistent 20 percent increase in the risk of type 1 diabetes. It is important to stress that the reason for this is still not understood. It is possible that children born by Caesarean section differ from other children with respect to some unknown characteristic which consequently increases their risk of diabetes, but it is also possible that Cesarean section itself is responsible.

"Type 1 diabetes occurs when the immune system destroys the insulin-producing cells in the pancreas, and one theory suggests that being born by Caesarean section may affect the development of the immune system because babies are first exposed to bacteria originating from the hospital environment rather than to maternal bacteria."

Around one in four babies in Northern Ireland is delivered by Caesarean section, which is significantly higher that the World Health Organization's recommended rate of 15 percent.

Iain Foster, Director of Diabetes UK Northern Ireland, said: "Not all women have the choice of whether to have a Caesarean section or not, but those who do may wish to take this risk into consideration before choosing to give birth this way.

"We already know that genetics and childhood infections play a vital role in the development of type 1 diabetes in children, but the findings of this study indicate that the way a baby is delivered could affect how likely it is to develop this condition later in life. Diabetes UK Northern Ireland would welcome more research in this area."

Source: Queen's University, Belfast, Ireland, and EurekaAlert!