Research

Hormonal

Obesity (BMI > 30 kg/m2) significantly impairs female fertility by causing insulin resistance, altering adipokine profiles (high leptin, low adiponectin), and disrupting the hypothalamic-pituitary-gonadal axis, leading to ovulatory disorders and reduced spontaneous conception rates.

If you have a BMI over 30, your risk of infertility increases by 5% for every point above 29. This is driven by hormonal imbalances like insulin resistance and altered leptin levels. Weight loss is recommended to improve fertility outcomes, as it can restore hormonal balance and improve oocyte quality.

GoodRefutesHIGH confidence
In ovulatory but subfertile women the chance of spontaneous conception decreases by 5% for each unit increase in the BMI (body mass index) exceeding 29 kg/m2... the increased risk of subfecundity and infertility in overweight and obese women is associated with not only impairment at the level of the HPG axis, but also oocyte quality and uterine receptivity
Roberta Fontana et al. · Nutrients · 2016

Why this rating

The paper is a review citing multiple observational and mechanistic studies, establishing a strong correlation and plausible biological mechanism, though it lacks a single definitive RCT.

Source

The Deep Correlation between Energy Metabolism and Reproduction: A View on the Effects of Nutrition for Women Fertility

Roberta Fontana et al. · Nutrients · 2016

DOI 10.3390/nu8020087

narrative_reviewCited 212×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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