HFEA BMI analysis
Research type
Research Study
Full title
Study Title: Association between the body mass index of women undergoing in vitro fertilisation treatment and treatment outcomes: a population-based study of the Human Fertilisation and Embryology Authority database
IRAS ID
263524
Contact name
Moscho Michalopoulou
Contact email
Sponsor organisation
University of Oxford / Research Governance, Ethics & Assurance Team
Duration of Study in the UK
3 years, 0 months, 31 days
Research summary
Carrying excess weight is associated with increased risk of infertility. Numerous studies have reported lower success and higher risk of complications during in vitro fertilisation (IVF) in women with higher body mass index (BMI), compared to women with BMI in the healthy category. These studies have informed UK clinical guidelines which state that women with higher BMI should be advised to lose weight before IVF to increase their chances of getting pregnant. NHS fertility clinics have also set upper BMI cut-offs for accessing IVF. As a result, many women who need IVF are unable to access it because of their high BMI, yet NHS support to help these women lose weight is limited, and many are unable to afford private support. However, the evidence base for the guidelines is limited. No study has investigated the association between BMI and IVF outcomes using a large number of women representative of the UK population, and most studies have analysed a limited number of treatments from single fertility centres. In addition, fertility decreases and BMI increases with age, and women from certain ethnicities are more likely to have higher BMI, but the influence of these factors on the relationship of BMI with IVF outcomes is unclear. We will analyse whether and how the BMI of women undergoing IVF treatment in the UK is associated with treatment outcomes using data from the UK Human Fertilisation and Embryology Authority. We will also present results separately by whether IVF treatment was NHS- or privately-funded, and we will examine whether the association varies by age and ethnic group. The results will clarify the association of BMI with IVF outcomes, and develop the evidence base on which to make decisions to achieve good and equitable outcomes in the treatment of women who need IVF.
REC name
South Central - Berkshire B Research Ethics Committee
REC reference
24/SC/0359
Date of REC Opinion
29 Oct 2024
REC opinion
Favourable Opinion