The relation of the HBsAg carrier state with fertility parameters and the sex ratio of offspring was studied in 1129 married women in 12 villages from different areas in Greece, in whom blood samples were tested for HBsAg. The results were compared between the group of HBsAg asymptomatic carriers and the HBsAg-negative group. An increase of the sex ratio was found in the group of HBsAg carriers. Furthermore, a decrease in the live births and a reduction in the number of female children were observed. It is concluded that a fertility disturbance in the HBsAg-positive group is probably responsible for the alteration of the sex ratio. An immunological mechanism may be the cause of the fertility disturbance found in the HBsAg carriers.
