Testicular changes in newborn rats exposed to phototherapy.

In this study we investigated the long-term effects of 72-h continuous phototherapy on the reproductive system of newborn rats. The animals' weight, fertilization rates, and number of newborn and histopathological changes in the gonads in a normal group not exposed to phototherapy and in the test animals were compared. At the age of 24 weeks there were no significant differences between the two groups, apart from the histology of the testicles of the male rats who were exposed to the phototherapy. The study group showed a significantly reduced diameter of the seminiferous tubules when compared to the controls (P < 0.001). It can be postulated that phototherapy may cause histological degenerative changes in the structure of the rat's testes, even though there were no changes in fertilization rates. Further studies are necessary to reveal the effects of phototherapy on humans and to determine the effects, if any, on fertility.