Research

Hormonal

Obesity reduces oocyte quality and maturity, leading to lower fertilization rates and increased miscarriage, independent of the number of follicles developed.

If you are obese, your eggs may be less mature and fertilize less efficiently, even if you produce many follicles during IVF. This increases the risk of miscarriage. Losing weight before IVF can improve egg quality and increase your chances of a successful pregnancy.

ModerateSupportsMEDIUM confidence
In a study done to assess the impact of isolated obesity upon ICSI outcome, it was observed that obese women (BMI >30 kg/m2) required higher total doses of gonadotrophin stimulation, despite significantly fewer oocyte–cumulus complexes and metaphase II oocytes being retrieved, suggesting that obesity may independently be a risk factor for impaired oocyte maturation.
Christopher Brewer et al. · Reproduction · 2010

Why this rating

The paper notes heterogeneity in studies, with some showing reduced oocyte quality and others not, suggesting the effect may be context-dependent.

Source

The adverse effects of obesity on conception and implantation

Christopher Brewer et al. · Reproduction · 2010

DOI 10.1530/rep-09-0568

narrative_reviewCited 492×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →