The Effect of Weight Loss Before In Vitro Fertilization on Reproductive Outcomes in Women With Obesity : A Systematic Review and Meta-analysis
Abstract
Background: It is unclear whether weight loss before in vitro fertilization (IVF) improves reproductive outcomes in women with obesity.
Purpose: To assess whether weight loss interventions before IVF improve reproductive outcomes.
Data sources: Five electronic databases through 27 May 2025.
Study selection: Randomized controlled trials (RCTs) in women with obesity who were offered a weight loss intervention before planned IVF.
Data extraction: Dual independent screening, data extraction, and assessment of risk of bias (RoB) and certainty of evidence. Primary outcomes were pregnancy and live birth rates. Where appropriate, studies were pooled using random-effects meta-analyses.
Data synthesis: Twelve RCTs (1921 randomly assigned participants) were included, 7 of which had high RoB. There was moderate certainty that pre-IVF weight loss interventions were associated with an increase in total pregnancy rates (risk ratio [RR], 1.21 [95% CI, 1.02 to 1.44]; 11 studies) and pregnancies resulting from unassisted conception (RR, 1.47 [CI, 1.26 to 1.73]; 10 studies), whereas the effect on pregnancies resulting solely from IVF was uncertain. Weight loss interventions were not associated with pregnancy loss rates (RR, 1.05 [CI, 0.98 to 1.13]; 8 studies; moderate certainty), but their effect on live birth rates was unclear (RR, 1.15 [CI, 0.95 to 1.40]; 9 studies; very low certainty).
Limitations: Studies were small, had high RoB, and often did not report important outcomes, such as live…
How strong is the evidence?
Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 1,921 participants or records.
Read the paper
Related studies
- Increased expression of circulating miRNA-93 in women with polycystic ovary syndrome may represent a novel, non-invasive biomarker for diagnosis
- Identification of key genes associated with polycystic ovary syndrome (PCOS) and ovarian cancer using an integrated bioinformatics analysis
- Identification of key pathways and genes in polycystic ovary syndrome via integrated bioinformatics analysis and prediction of small therapeutic molecules
- Regulation of Androgen Receptor Expression Alters AMPK Phosphorylation in the Endometrium: In Vivo and In Vitro Studies in Women with Polycystic Ovary Syndrome
- Effect of oral administration of low-dose follicle stimulating hormone on hyperandrogenized mice as a model of polycystic ovary syndrome
- Systems pharmacology to investigate the interaction of berberine and other drugs in treating polycystic ovary syndrome
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.