Deposited in DRO : 17 March 2016 Version of attached le : Accepted Version Peer-review status of attached

Objective: To assess whether the quality of early childhood environments among different groups of Bangladeshi women, including migrants to the UK, contributes to variation in ovarian reserve and the rate of reproductive ageing in later life. Design: Cross-sectional study. Setting: London (UK) and Sylhet town, NE Bangladesh. Patients: 179 healthy women volunteers aged 35-59 divided into four groups: 1) 36 Bangladeshis living in Sylhet, Bangladesh; 2) 53 Bangladeshis who migrated to the UK as adults; 3) 40 Bangladeshis who migrated to the UK as children aged 0-16; and 4) a reference group of 50 women of European origin living in London.