Abstract

Obesity has become one of the most significant public health challenges of the 21st century and is increasingly 
recognized as a major determinant of reproductive health. This narrative review synthesizes current evidence on 
the effects of obesity on both female and male fertility, highlighting the complex physiological, metabolic, and 
endocrine pathways through which excess adiposity impairs reproductive outcomes. In women, obesity disrupts 
the hypothalamic–pituitary gonadal axis, contributes to anovulation, prolongs time to pregnancy, increases 
miscarriage risk, and reduces the success of assisted reproductive technologies (ART). In men, obesity is associated 
with compromised semen parameters, hormonal imbalance, delayed conception, and potential adverse effects on 
embryonic development. Central adiposity, metabolic syndrome, and obesity-mediated comorbidities further 
contribute to subfertility in both sexes. Pregnancy complications, including gestational diabetes, hypertensive 
disorders, preterm birth, and cesarean delivery, occur in a dose-dependent relationship with rising maternal BMI. 
The review also evaluates current interventions, including lifestyle modification, pharmacotherapy, and bariatric 
surgery, and explores their respective impacts on fertility outcomes. Despite growing evidence, significant 
methodological limitations and heterogeneity in definitions of obesity and fertility hinder comparability across 
studies. Strengthening standardized measures, improving long-term population studies, and enhancing integrated 
clinical and public health strategies are essential for reducing obesity-related reproductive burdens. Overall, 
obesity substantially influences reproductive physiology and outcomes, underscoring the need for early preventive 
care and targeted interventions in reproductive-age populations.