The Raine Study was commenced in 1990 as a long term follow up of children who underwent serial ultrasound examinations in-utero. These children have been followed-up as part of the Generation 2 Raine cohort. The men underwent a full reproductive assessment at aged 21 years of age and are currently undergoing a reproductive assessment at 33-35 years of age. This data will not be available for presentation as data collection is not complete. The focus of this talk will be the early life influences on male reproductive function when they were assessed at 21 years of age. They underwent hormone assessment, testicular ultrasound examination and a detailed semen analysis.