Association between preconception body mass index and fertility in adult female: A systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational studies (CEBM Level 3 for etiology/prognosis).
PubMed 39054661 · doi:10.1111/obr.13804
What was done
A systematic review and meta-analysis of literature indexed up to September 2023 was conducted across Web of Science, PubMed, Wiley, and ScienceDirect. The authors pooled data from 18 studies examining the association between female preconception body mass index (BMI) categories (underweight, overweight, obesity) and fertility outcomes, specifically time-to-pregnancy (TTP), subfecundity, and infertility.
What was found
Preconception obesity (fecundability odds ratio [FOR] = 0.76; 95% CI: 0.69, 0.83), overweight (FOR = 0.93; 95% CI: 0.88, 0.99), and combined overweight/obesity (FOR = 0.85; 95% CI: 0.80, 0.90) were significantly associated with prolonged TTP (reduced fecundability). Underweight was also modestly associated with prolonged TTP (FOR = 0.95; 95% CI: 0.91, 0.99). Overweight/obesity was associated with higher odds of subfecundity (OR = 1.44; 95% CI: 1.20, 1.72) and infertility (OR = 1.60; 95% CI: 1.31, 1.94).
Why it matters
This review synthesizes observational evidence showing that both extremes of preconception BMI, particularly obesity, correlate with reduced fecundity, reinforcing the clinical relevance of preconception weight management.
Limits
The total number of participants across the 18 studies is not stated in the abstract. Inter-study heterogeneity, confounding factors (e.g., age, coital frequency, male factor subfertility, polycystic ovary syndrome), and the specific designs of the included studies are not reported in the abstract. The underlying observational evidence limits causal inference.
Cited by
- supports Being either significantly underweight or significantly overweight reduces a woman's likelihood of getting pregnant.