We plan to use UK Biobank data to better understand the molecular basis of reproductive traits and disorders in men and women. This will cover genetic factors governing the start of reproductive ageing (puberty timing) through to the end (menopause age in women), in addition to reproductive disorders and traits such as sex hormone levels, fertility and polycystic ovary syndrome. Better understanding of the molecular basis of reproductive traits may lead to improvements in the prediction, identification and prevention of reproductive disorders. We plan to identify genetic variants associated with a broad range of reproductive parameters and disorders. This will include traits such as biochemical measures of sex hormones, self-reported disease status and other proxy measures of fertility such as number of children. We plan to use the entire dataset of both males and females to maximise statistical power.