ABSTRACT
Background: Obesity is a state of the excess buildup of fats where it leads to chronic low-grade inflammation, lipotoxicity, deranged endocrine system and the female sex hormones. It is speculated that each of these aspects plays a contributory role to infertility in obese. So, this review aims to look into changes in the endocrine system and the hypothalamic-pituitary-ovarian (HPO) axis in obese women that affect the female reproductive system and the correlation between each mechanism leading to infertility. Results and Discussion: Obese women are associated with higher levels of androgens and insulin, where the latter can further potentiate levels of the former. These two changes contribute the most to infertility, where effects include poor follicular growth, premature luteinization, atresia of ovarian cells and follicles, as well as poor endometrial development. Changes are also seen in levels of growth hormones (GH), adipokines like leptin and adiponectin, inflammatory mediators and ghrelin, which altogether alter the HPO axis, either through potentiating or inhibiting one another, leading to effects like ovulatory dysfunction, irregular menstruation, increased risks of miscarriages and greater failure rates in artificial reproductive technology (ART). In terms of management, this review will be focusing mainly on non-pharmacological approaches which include weight loss, dietary modification and physical activities, as well as exploring surgical approaches to weight loss. Weight reduction is the gold standard as it can reverse the changes in the HPO axis by improving insulin sensitivity, regulating sex hormones, and restoring balances to the adipokines and inflammatory mediators. Conclusion: Obesity is a state of excess in metabolically active adipose tissue, which causes changes in the HPO axis and subsequently damages the female reproductive system. The correlated mechanisms only partly explain how obesity leads to female infertility. Thus, different aspects of obesity would need to be explored and correlated to fully realize how it leads to female infertility.