How Weight Affects Fertility

Before couples even start thinking about having a baby, they should first consider their health. Both men and women’s health are fundamental priorities for overall wellness, and getting pregnant is no exception at all. Simply put, healthy people make healthy babies.

The Role of Fat

Discrepancies in body fat can disrupt the delicate balance between hormones. More body fat increases estrogen, and excess amounts of this hormone can throw off other hormones essential to female reproduction. Obesity is closely linked with Type II Non-insulin Dependent Diabetes, which can also adversely affect the normal menstruation process, and can make other illnesses more severe.

Less-than-normal levels of body fat are not healthy either, since this can result in anovulation, or the cessation of the normal ovulation process in the menstrual cycle. It turns out that being as little as 10 percent underweight can lead to a detrimental shift in hormone production. Low estrogen levels can cause reduced production of cervical mucus, which makes fertilization more difficult. Women who suffer from anorexia nervosa have irregular menstrual cycles.

Moreover, female athletes who engage in very intense exercise tend to have lower levels of FSH, and their exercise sessions tend to break down muscle by design, often leading to the muscles releasing ammonia, a chemical known for inhibiting pregnancy.

Weight vs. Fat – which is a more accurate (and useful) measurement?

BMI is one of the most widely used parameters for determining weight. Women whose BMI range is between 18.5 and 24.9 are defined as being normal. Twelve percent of infertility cases are women who are underweight, and 25% are overweight women. Weight tends to be problematic for fertility because being overweight usually means having a higher proportion of body fat.

But BMI measures body mass, not body fat. Women who exercise regularly generally have a greater muscle mass, which raises BMI, merely suggesting an increase in fat. Muscle weighs more than fat, so some women who have a healthy proportion of body fat, between 12 and 35 percent may be incorrectly diagnosed as overweight or even obese, even when their physiques suggest the opposite.

What You Can Do

Sedentary women with increased body fat (and their partners) who are trying to conceive should exercise regularly to maintain a healthy level of body fat. Exercise for them improves metabolism and circulation, promoting egg production. Also, exercise is an excellent way to relieve stress, another factor that undermines fertility. Women who have a lower percentage of body fat should try to gain weight, not just by eating more, but moreover by eating right while maintaining a reasonable level of activity. Gaining as little as two or three pounds can make all the difference.

During their normal menstrual cycle, women who find it difficult to conceive should keep a thermometer handy to measure their basal body temperature, as body temp is correlated with normal ovulation. These steps are very easy to do and can improve one’s chances of getting pregnant.