Antibiotic Exposure Before Age 2 Tied to Increased Risk of Pediatric IBD

ORLANDO -- Exposure to antibiotics before 2 years of age appeared to increase the risk of developing pediatric inflammatory bowel disease (IBD), according to a Norwegian nationwide study.

Overall, children exposed to antibiotics -- even in utero -- had a 1.4-fold increased risk of developing IBD, reported Svend Andersen, MD, of the University of Oslo in Norway, during the Advances in Inflammatory Bowel Diseases annual meeting.

After adjusting for variables, including maternal smoking and other factors, Andersen and team found that risk of IBD was increased with antibiotic exposure during the last trimester of pregnancy (adjusted OR 1.24, 95% CI 1.01-1.51, P=0.01) and before 2 years of age (aOR 1.40, 95% CI 1.21-1.61, P<0.001), as well as with two or more courses of antibiotics at 0 to 2 years of age (aOR 1.51, 95% CI 1.27-1.79, P=0.007) and with use of broad-spectrum antibiotics (aOR 2.36, 95% CI 1.45-3.83, P=0.001).

This study aimed to try to clean up the controversy concerning early antibiotic exposure, Andersen said. "There have been studies that showed a fivefold [increased] risk of developing inflammatory bowel disease and other studies that have found no risk."

Co-author Tomm Bernklev, PhD, of Oslo University Hospital, told MedPage Today that "many of these antibiotics are prescribed for children who develop things like ear infections, but in Norway, we have strict regulations regarding prescription of antibiotics, while other areas of Europe have more relaxed rules. But in some of these countries, they have less inflammatory bowel disease. So there is some X factor that may be in play."

Andersen noted that when immigrants from countries in Asia come to Norway, their risk of IBD compared with that of the general Norwegian population is low. However, their grandchildren living in Norway have the same risk as the rest of the population.

Commenting on the study, Svein-Oskar Frigstad, MD, PhD, of Vestre Viken Bærum Hospital and the University of Oslo, pointed out that "this is a registry study, and it indicates that antibiotics before birth and at very young ages may influence the microbiome of the gut, and that may increase the risk of developing inflammatory bowel disease."

"But this is an epidemiological study that includes a large population, and there are a lot of things we don't know about the individuals in the study," he told MedPage Today. "But if the child is in front of you and has an infection, you need to treat that, regardless of the risk of developing inflammatory bowel disease later in life."

"It is always important to remember that, in the big picture, the use of antibiotics is only one risk factor, and there will never be just one factor that will fix everything," he added. "It is important that this is discussed with the parents when considering treatment."

Frigstad also noted that antibiotics are over-used worldwide, especially in countries where they can be purchased without prescriptions. "Antibiotics help if there is actually an infection that will respond to it, but may not be warranted for everything else," he said.

For this study, Andersen and colleagues used data from the Norwegian Patient Registry, the Norwegian Prescription Database, the Medical Birth Registry of Norway, and Statistics Norway on 536,821 children and adolescents born from 2004 through 2012, 758 of whom had pediatric IBD. They were followed through 2020.

Of those diagnosed, 44% were girls; 403 had Crohn's disease, 243 had ulcerative colitis, and 112 had undefined IBD.

Comment