Research in Germany linked higher infection risks, especially for diarrhea, to babies who swam in pools during their first year of life.

However, the study, published in the International Journal of Hygiene and Environmental Health, found no increased risks for atopic diseases -- which is when the immune system is dysregulated, resulting in allergic inflammation.

"In this way, the study shows that allowing babies to swim is possibly not as harmless with regard to infections as has been presumed till now," study co-author, Dr. Joachim Heinrich, said in a statement. He leads the research unit environmental epidemiology at the GSF Institute for Epidemiology.

The study looked at 2,191 babies who were re-examined at age 6. Besides keeping track of swimming-pool attendances during infancy, the researchers also used parental interviews to determine information about the children's health and lifestyle.

Those babies that had not taken part in swimming as infants showed a much lower infection rate, especially in the cases of diarrhea and otitis media in the first year of life.