Weighing heavy on fertility

The pandemic has added to the obesity burden and as a result, the challenge of managing weight is another task as it can impair reproduction, writes Dr Sumana Gurunath

Globally, an overweight population and obesity, in particular, have become emerging epidemics and a major public health concern along with the dual nutrition burden. While our country has been fraught with malnutrition for many centuries, rapid urbanisation, industrialisation, a sedentary lifestyle and consumption of energy-dense processed foods have seen a rapid surge in the prevalence of obesity. The pandemic has added to the obesity burden and as a result, the challenge of managing weight is another task. During the pandemic, fitness centres have been shut down, our activity may be decreasing, or we may be working from home and not moving as much. The trends are alarming as the number of overweight people has more than doubled in the last two decades. Besides all this, did you know, obesity not only increases the risk of developing increased cholesterol, hypertension, diabetes and heart disease; but also has a negative impact on male and female fertility? It can impair reproduction in both men and women, leading to infertility, and can result in subsequent complications in pregnancy. Obesity is correctable and weight loss is achievable with discipline and lifestyle changes. Let’s bust some common myths surrounding weight:

I weigh 65 kgs and I am not overweight: Obesity is defined by certain measurements such as BMI, waist circumference and waist-hip ratio. BMI is a ratio of weight (kg)/Height (m). BMI between 25–29.9 is defined as overweight and >30 is obese. Asians have been found to be more prone to heart disease at lower BMI and so the Asian definition for overweight is 23-24.9 and obese is >25. Waist circumference is a better indicator of central or abdominal obesity which is more dangerous. A value of >90 cms for men and >80 cms for women is high. Greater deposition of abdominal fat increases insulin resistance and has higher morbidity. Hence instead of just measuring one’s weight, calculation of these indices gives us a better perspective of the problem.

I see so many women who are overweight but get pregnant. I should not have a problem: Many obese men and women are fertile. However, obese women are more likely to have irregular periods due to disturbed ovulation. Even in women with regular periods, obese women take longer to conceive as compared to normal-weight women. Obesity is also known to worsen the hormone imbalance in polycystic ovarian syndrome (PCOS). So, if you are having a problem conceiving, obesity is likely to worsen it.

Obesity does not have any impact on the success of infertility treatments: If you are obese, you are more likely to need higher doses of medications to induce ovulation, less likely to respond to oral agents and need more cycles of treatment to conceive. Several large studies on women undergoing IVF confirm that obesity reduces the response to hormone stimulation (need higher doses of injections, increase in the duration of stimulation, increased cost), reduces the number of eggs retrieved, lowers egg quality and pregnancy rates of treatment. Studies have found a 2% decrease in the live birth rate for every 1 unit increase in BMI. Obesity reduces the ability to conceive naturally and the success of fertility treatment.

Being obese has nothing to do with low sperm counts: Not all obese men have infertility. But those who do may have erectile dysfunction, low sperm counts and motility. Obesity, especially abdominal obesity is associated with a greater chance of having abnormal semen parameters and infertility. The peripheral fat brings about the conversion of circulating male hormone or testosterone into the female hormone/estrogen. This lowers the testosterone levels in the body which is essential for sperm production and hence, impacts semen quality.

I am going to have an uncomplicated and comfortable pregnancy. Weight has no effect on pregnancy and the baby: Obese women are more likely to develop complications in pregnancy. Obesity is associated with a greater risk of miscarriage, developing gestational diabetes, hypertension, pre-term delivery and stillbirth. Delivery can be more difficult and complicated requiring caesarean section or instrumental delivery. Babies born to obese mothers can have a mildly increased risk of abnormalities and are more likely to be obese themselves.

To improve my fertility, I have to reach my ideal body weight: Improvement in fertility is observed even with a small weight loss of 5-10%. It is not mandatory to reach one’s ideal weight which may be an arduous task for many. This makes the goal easier and more attainable. Weight reduction regularises periods, resumes ovulation and facilitates early conception.

(The author is a consultant in infertility & reproductive medicine.)