The object of this paper is to assess how far developments in the labour market can help to explain the fluctuations in births which have been recorded in England and Wales between 1952 and 1980. We examine separately the period rate of women from each of the first four parities proceeding to another birth. Our analysis shows that different birth orders respond differently to economic variables, and that women of different ages but the same parity respond differently. We have found that growing real wages for both men and women tend to deter older parents from adding to existing families. During the early stages of family building, births are inhibited by labour markets favourable to women. But conditions in the labour market for men have the opposite effect on early breeding.