a1 Department of Population Dynamics, Johns Hopkins University, Baltimore
a2 Institute for Cancer Research, Philadelphia, USA
The relationship between hepatitis B infection in parents and the sex ratio at birth of their offspring is examined in four populations. The hepatitis B carrier state in parents may increase the sex ratio of their offspring, but it seems that immunization against hepatitis B is unlikely to affect the sex ratio at birth of future generations.
(Received June 09 1987)