Obesity & Infertility

Obesity & Infertility

The global prevalence of obesity and overweight is steadily increasing and has reached epidemic proportions. 
Obesity rates in developed nations have risen due to lifestyle changes such as less physical activity, changes in eating choices, and increased calorie consumption.

Fat women are three times more likely to experience infertility than non-obese women. 

Obesity has a negative impact on all physiological systems, including reproductive health.

Obesity is common among infertile women, and it is commonly acknowledged that there is a link between obesity and failure to conceive. 

Overweight women are more likely to experience menstrual disorders, miscarriage, and anovulation.

Obesity-related infertility is caused by a variety of factors, including impaired ovarian follicular development, decreased qualitative and quantitative egg development, less fertilization, improper embryo development, and less chance of implantion. 

Obese women are less likely to have a healthy infant due to impaired implantation and conception rates, higher miscarriage rates, and increased maternal and fetal issues throughout pregnancy. 

Obese women's increased peripheral aromatization of androgens to estrogens disrupts gonadotropin synthesis. 

Insulin resistance and hyperinsulinemia in obese women result in hyperandrogenemia. 

Lower levels of sex hormone-binding globulin, growth hormone, and insulin-like growth factor-binding proteins are associated with higher levels of leptin. 

Adipokines are cytokines primarily produced by adipocytes. Leptin is one of several adipokines. Adipokines are hormones that serve as signaling molecules. Deviation from normal adipokine levels can cause inflammation and abnormal cell communication, leading to a reduction in cellular metabolism and function. Excess or deficiency of white adipose tissue is known to induce sexual development disorders, pubertal illnesses, and fertility problems. 

Leptin also influences reproductive processes by controlling embryo cleavage and development. This issue may contribute to obese women's poor reproductive outcomes. 

Adipose tissue buildup in women worsens polycystic ovarian syndrome (PCOS), anovulation, and can result in hypothalamic hypogonadism. Individuals with polycystic ovarian syndrome (PCOS) have elevated amounts of deleterious adipokines, including tumor necrosis factor-alfa (TNF-α), and reduced levels of helpful adipokines, such as adiponectin, due to adipose tissue failure. 

Adiponectin is the primary protein produced by adipose tissue and circulates throughout the body. Unlike other hormones related with adipose tissue, adiponectin levels in obese women exhibit a distinct pattern of fluctuation with weight loss. Adiponectin increases glucose absorption in the liver and muscle while decreasing glucose metabolism in the liver. As a result, insulin sensitivity is decreased. 

Polycystic Ovarian Syndrome

Polycystic Ovarian Syndrome (PCOD) is a medical disease in which the ovaries overproduce immature or partially developed eggs. Poor lifestyle choices, obesity, stress, and hormonal imbalances are common causes of this illness. 

Polycystic ovaries are larger than normal ovaries and contain double number of follicles. 

Polycystic ovarian syndrome (PCOS) is a medical disorder that predominantly affects the menstrual cycle, fertility, hormone levels, and physical appearance. 

Endocrine problems in PCOS cause the ovaries to produce an excess of androgens, increasing the likelihood of cyst formation in eggs. 

PCOS is a metabolic disease characterized by elevated levels of androgens. Previously, PCOS was only categorized as a hyperandrogenic condition that can cause infertility. PCOS is related with an increased risk of metabolic illnesses such as insulin resistance, hyperinsulinism, impaired glucose tolerance, and obesity. 

Insulin resistance and hyperandrogenemia are significantly more common in obese women, particularly those with central obesity. 

Elevated androgen levels generated by high insulin levels promote granulosa cell death, which can impair ovarian function. 

Obesity and its influence in IVF treatment

Higher BMI status is linked to an increased risk of spontaneous miscarriage in patients who have received various forms of assisted reproductive technology (ART), including embryo transfer using donor oocytes. The likelihood of miscarriage in obese women was found to be 38.1%, while in patients with a normal BMI, the rate was 13.3%. 

Treating anovulatory infertility in obese women is difficult due to their lower chances of conceiving after assisted reproductive technology (ART). This is linked to their requirement for a higher dose of gonadotropin, a poor response to ovarian stimulation, and a greater chance of miscarriage.