The prevalence of obesity and overweight is increasing worldwide. Obesity has detrimental influences on all systems of the body including the reproductive health. Several studies have shown that the risk of infertility is three times higher in obese women when compared to non-obese women. Overweight women have a higher incidence of menstrual dysfunction and anovulation leading to higher risk of infertility, low conception rate, higher miscarriage rates and pregnancy complications. Obese women have poor reproductive outcomes in natural as well as assisted conception. Weight loss has significant beneficial effects on the reproductive outcomes in these individuals.
According to WHO, Body Mass Index (BMI) in the range of 25-39.9 is considered as overweight and the person is considered obese when the BMI is more than or equal to 40.
[BMI is calculated by the simple formula BMI = Weight (in kg) divided by Height (in metre)2]
How does being overweight affect my fertility?
A fine hormonal balance regulates the menstrual cycle. Overweight and obese women have higher levels of a hormone called Leptin, which is produced in fatty tissue. This can disrupt the hormone balance and lead to reduced fertility.
Excess weight, particularly excess abdominal fat, is linked to insulin resistance (the body has to produce more insulin to keep blood sugar levels normal) and decreased levels of Sex Hormone Binding Globulin (SHBG), a protein that is involved in the regulation of the sex- hormones androgen and oestrogen. This increases the risk of irregular menstrual cycles, which in turn reduces fertility. Increased weight also increases the risk of PCOD and anovulation making obese women difficult to conceive. Even if there is ovulation, the quality of eggs produced is reduced reducing the chance of achieving a pregnancy. And when couples use IVF to conceive, the chance of a live birth is lower for women who are over- weight or obese than for women with normal BMI.
OBESITY AND MALE INFERTILITY
Excess weight also lowers fertility in men and this is due to a combination of factors. These include hormonal imbalance, sexual dysfunction and other health conditions linked to obesity such as type 2 diabetes and sleep apnoea ( which are both associated with lowered testosterone levels and erectile problems). Obesity also interferes with sperm concentration and the sperms ability to swim well
OBESITY AND TREATMENT IN INFERTILITY
Sometimes treatment for fertility issues starts with getting to a healthy weight. Losing weight is a simple concept, but in practice, it’s not always easy. Studies have shown that even a small weight loss in anovulatory obese infertile women resulted in improvements in ovulation, pregnancy rate and pregnancy outcome. Overweight and obese individuals should be encouraged to start losing weight before starting the infertility treatment to reduce the obesity related poor obstetrical outcomes. Although weight loss is the gold standard of treatment in women with high BMI, ART (Assisted Reproductive Treatment) should not be delayed too much because of increasing age. There are many other ways of reducing body fat including following a healthy diet, administrating diet pills, increasing energy expenditure by exercise and workouts, or surgically removing abdominal fat/ surgical fitting of a gastric band in order to decrease abdominal weight. Even in obese males, losing excess weight has shown to increase sperm concentration and improve erectile dysfunction. Testosterone therapy may also be used to improve hormonal imbalances and fertility.
Making simple lifestyle changes will make a difference to your overall health, even if they don’t lead to weight loss. Begin making these changes before you start trying to conceive, and keep them up throughout your pregnancy and beyond.
