The aims of this study are the following: to describe the female population of reproductive age having bariatric surgery in the UK, to assess the age and ethnicity of women accessing surgery, and to assess the effect of bariatric surgery on factors that underlie fertility and pregnancy outcomes. Methods Demographic details, comorbidities, and operative type of women aged 18–45 years were extracted from the National Bariatric Surgery Registry (NBSR). A comparison was made with non-operative cases (aged 18–45 and BMI ≥40 kg/m2) from the Health Survey for England (HSE, 2007–2013). Analyses were performed using BR^ software. Results Data were extracted on 15,222 women from NBSR and 1073 from HSE. Women aged 18–45 comprised 53 % of operations. Non-Caucasians were under-represented in NBSR compared to HSE (10 vs 16 % respectively, p