Workshop recommendations for the preconception cohort of the National Children's Study.

This paper summarises discussions on incorporating preconception recruitment in the National Children's Study (NCS); these were part of the workshop on Expanding Methodologies for Capturing Day-Specific Probabilities of Conception. Four key issues were discussed in relation to the NCS: (1) differences between pregnancy 'planners' and 'non-planners'; (2) a tiered approach to preconception data collection; (3) data gaps in preconception studies; and (4) assessment of early pregnancy in subsequent pregnancies for women with a child already in the study. Practical recommendations were developed for each theme, which have relevance for other prospective studies of conception, pregnancy and human development.