Published online by Cambridge University Press: 31 July 2008
Birth records in Birmingham were examined for evidence of reproductive compensation following a fetal or infant death. Mothers with a stillbirth, a neonatal death, or a post-neonatal death in 1964 were identified, controls were selected, and subsequent reproductive patterns up to 1969 were compared. There was substantial reproductive compensation following the post-neonatal deaths and a lesser degree after neonatal deaths. Stillbirths were followed by compensation in the first year but this was not maintained and there was a net reduction of effective fertility over the whole 5-year period. Within this pattern, the extent of compensation varied according to the number of older surviving children. Both fetal and neonatal deaths tended to recur. There is evidence that reproductive compensation is partly attributable to pre-existing fertility differentials, but also to eventdetermined modifications of reproductive behaviour. With respect to haemolytic disease of the newborn the data provide some evidence in support of the theory that gene frequency stability depends upon reproductive compensation, but the interpretation of the data in this respect is not completely reliable.