Researchers link Caesarean section births to genetic changes

Stockholm - Swedish researchers have detected a possible link between babies born by planned Caesarean section and the increased risk of developing diseases like diabetes, cancer and asthma in later life, according to a study published in the July edition of Acta Paediatrica. Babies delivered with planned Caesarean section had changes to the DNA pool in their white blood cells, possibly connected to altered stress levels, the study conducted at the Karolinska Institute said. 'Our results provide the first pieces of evidence that early so- called epigenetic programming of the immune system during birth may have a role to play,' Professor Mikael Norman of the Department of Clinical Science, Intervention and Technology said. The findings are interesting as Caesarean section delivery is on the rise worldwide. At present it is the most common surgical procedure among women of child-bearing age. The team took blood samples from umbilical cords from 37 newborn infants just after delivery, and collected new samples three to five days after birth. The blood samples were analyzed to study the degree of DNA- methylation, or chemical altering of the DNA, in the white blood cells. These cells are a key part of the immune system. The analysis indicated higher DNA-methylation rates among the 16 babies born by Caesarean section immediately after birth compared to 21 babies born by vaginal delivery. Three to five days after birth, DNA-methylation levels had dropped in infants delivered by Caesarean section so that there were no longer significant differences between the two groups. More research was necessary to determine why DNA-methylation was higher after Caesarean section deliveries, the researchers said. 'We believe that our findings open up a new area of important clinical research,' lead author Titus Schlinzig, research fellow at Karolinska Institutet, said. Full details available in Acta Paediatrica 2009, 98, 1096-99.