Abstract and Introduction
Obesity exacerbates the phenotype of polycystic ovarian syndrome (PCOS) including infertility as well as reducing the efficacy and access to fertility treatments. Weight management is, therefore, a key component of treatment for women with PCOS and coexistent obesity. Many women with PCOS describe significant difficulty losing weight and treatment options are limited. The first-line treatment is lifestyle interventions though the weight loss and any impact on fertility are limited. No one dietary strategy can be preferentially recommended based on current evidence. While very low energy diets can result in significant weight loss the evidence for impact on fertility is limited. Pharmacotherapy, including a range of treatments can result in marked weight loss and there is some evidence of improved rates of conception including spontaneous and in response to assisted reproduction treatment. As with pharmacotherapy, data regarding bariatric surgery is largely from nonrandomized studies and though the significant weight loss is anticipated to improve fertility the available data prevents firm conclusions. Clinicians and patients must consider the magnitude of weight loss to be targeted as well as the anticipated fertility treatment required and the timeline of treatment when deciding upon the personalized weight loss strategy. Clinicians and patients should be confident in targeting the most appropriate treatment early in the patient's management to avoid unnecessary delays.
Polycystic ovarian syndrome (PCOS) affects 6%–10% of women of reproductive age. Obesity is a major contributor to subfertility in PCOS via its impact on hyperandrogenism, hyperinsulinaemia, inflammation, insulin resistance and the interplay between the hypothalamic–pituitary–ovarian axis, follicle development, oocyte quality and endometrial receptivity (Figure 1).
An overview of the mechanisms linking PCOS and obesity that contribute to subfertility. PCOS and obesity can contribute to a proinflammatory, hyperinsulinaemic, insulin-resistant state that can drive subfertility both by the effects of the resulting hyperandrogenaemia as well as effects on the developing oocytes and the endometrium. IR, insulin resistance; LH, luteinizing hormone; PCOS, polycystic ovarian syndrome; SHBG, sex hormone-binding globulin
Obesity is associated with reduced reproductive outcomes regardless of the mode of conception (unassisted, ovulation induction, in vitro fertilization, intracytoplasmic sperm injection), a barrier for accessing assisted conception and is associated with adverse maternal and foetal outcomes.
Weight loss is an important treatment target in women with PCOS and obesity that are seeking fertility especially given that women with PCOS can lose similar amounts of weight to women without PCOS regardless of treatment modality despite earlier reports to the contrary.
Here, we provide a narrative review to support clinicians managing obesity in women with PCOS, obesity and subfertility. We have conducted a Medline search using a combination of specific search terms: obesity, weight loss, fertility, polycystic ovaries (or ovarian or ovary) syndrome, maternal outcomes, pregnancy outcomes, lifestyle interventions, low energy diet, low carbohydrate diet, low-fat diet, weight loss pharmacotherapy, antiobesity medication, bariatric surgery and the names of individual bariatric procedures in the title or abstract. We did not incorporate a body mass index (BMI) cut-off within the identified literature. We prioritized the reporting based on evidence hierarchy giving preference to systematic reviews (SRs), and randomized controlled trials (RCTs). While a multitude of studies have examined pharmacotherapy in PCOS we highlighted studies aimed at targeting weight loss that reported any fertility-related outcome.
Clin Endocrinol. 2022;97(2):208-216. © 2022 Blackwell Publishing