(RxWiki News) Could the birth process have a role in immune disease development? A common birthing method may raise babies' risk of immune diseases later, a new study found.
A Danish research team found that people born by cesarean section (C-section), rather than vaginal delivery, faced a higher risk for several immune diseases later.
Those immune diseases were asthma, juvenile arthritis, inflammatory bowel disease, immune deficiencies and connective tissue disorders. People born by C-section also faced a higher risk of developing leukemia as adults.
“Our findings also support the hypothesis that [the time just before and after birth] is important for later development of chronic diseases,” the authors of this recent study wrote.
Hans Bisgaard, MD, DMSc, of the University of Copenhagen and Danish Pediatric Asthma Center in Denmark, led the research team.
The immune system protects the body from disease. If this system does not work properly, it can play a role in the development of certain diseases.
Dr. Bisgaard and colleagues studied 1.9 million children. They collected data from a Danish national database on whether these children were born by C-section or vaginal delivery. The team also noted the diseases these people developed between 1977 and 2012.
In a C-section, the baby is born during surgery where an incision is made in the mother's stomach.
Dr. Bisgaard and team found an increase in the chance of developing several diseases of the immune system in people born by C-section — compared to those born by vaginal delivery. The odds of developing diseases of the immune system itself — such as immune deficiencies — increased by 46 percent. The risk for asthma in these patients went up 23 percent, and inflammatory bowel disease risk jumped by 20 percent.
Asthma is a chronic respiratory disorder. In inflammatory bowel disease, the digestive tract is inflamed. Ulcerative colitis and Crohn's disease are both types of inflammatory bowel disease.
People who were born by C-section were 17 percent more likely to develop leukemia, 11 percent more likely to develop connective tissue disorders and 10 percent more likely to develop juvenile arthritis than those who were born vaginally.
Leukemia is a type of blood cancer that begins in the bone marrow. Connective tissue disorders include many diseases of parts of the body like the bones, cartilage and joints. Juvenile arthritis refers to arthritis — marked by chronic joint pain, swelling and stiffness — in patients younger than 17.
Since one risk factor — C-section birth — was tied to several immune diseases, Dr. Bisgaard and team suggested that those diseases may have a common trigger. They said that trigger could be in the birth environment itself.
Exposure to germs strengthens the immune system. Antibiotics — medications that fight bacteria — given to women who have C-sections might reduce the number of germs a newborn is exposed to, Dr. Bisgaard and team said. A baby born vaginally is exposed to many germs.
This study was published online Dec. 1 in Pediatrics.
The research was funded by the Danish Council for Strategic Research and the Danish Medical Research Council, among others. The authors disclosed no conflicts of interest.