The Relationship Between Weight and Fertility

Being overweight or obese is known to lead to health consequences, which is bad news considering the increasing number of Australians who are above the healthy weight. The unfortunate thing is, not only will affect the individual’s health but it can also lower the chances of having a child.

How Excess Weight Affects A Woman’s Fertility

In order to have a regular menstrual cycle, hormonal balance is necessary. When a woman is overweight or obese, her body produces more leptin, a hormone that is produced in fatty tissue. It can lead to issues with hormone balance and affect her fertility.

Plus when there is more fat and when the body fat is distributed in the wrong places, it can disrupt the body’s hormonal mechanisms. Thus, the more excess weight and abdominal fat you have, the higher your risk of fertility problems.

This extra weight and abdominal fat will also lead to the body’s decreasing resistance to insulin, meaning the body will need to produce more so that the blood sugar levels stay normal.

It can reduce the body’s production of SHBG (the sex-hormone-binding globulin), which is a protein required to regulate the levels of the 2 sex hormones estrogen and androgen.

Moreover, women who are obese or overweight are more likely to have irregular menstrual cycles, which directly influences fertility. In fact, a study has concluded that women who are obese have lower success rates in conceiving one year after they stop taking contraception. Compared with the 81.4% success rate of normal-weight women, only 66.4% of obese women got pregnant.

At times, when the hormonal balance is disrupted by being overweight or obese, the risk of anovulation (when the ovaries do not release an egg) also increases.

Naturally, when a woman does not ovulate, it is not possible to conceive. Unfortunately, when a woman has a body mass index (BMI) of over 27, they are three times less likely to conceive because they have not ovulated.

Even when they do produce eggs, the quality of these eggs is lower compared to the eggs produced by women of healthy weight. This means they are less likely to turn into a viable pregnancy. Every single unit increase in BMI, especially above 29, will reduce a woman’s chances of getting pregnant within a year by about 4%.

If a woman has a BMI of 35, this means she has a 26% lower chance of conceiving, and when she has a 40 BMI, the chances go down by 43% compared to women with normal BMIs. Even if they try out IVF, overweight or obese women have lower chances of live birth. Overweight women have 9% fewer chances of live birth while obese women have 20% less.

How Excess Weight Affects A Man’s Fertility

Not many people realize that in men, being overweight or obese can also lead to lower fertility because of a combination of factors. These include problems with hormones, sexual dysfunction, as well as health conditions that are caused by obesity.

For example, they are more likely to have type 2 diabetes and sleep apnoea, which leads to lower testosterone levels and erectile issues. In fact, health professionals estimate that an extra 10 kilos will reduce their fertility by 10%.

Studies have also shown that obese men who are infertile or are having problems conceiving still suffer lower success rates of conceiving even if they go through IVF or other assisted reproduction technologies (ART).

Experts believe that obesity does not only lead to lower sperm quality but it also alters the sperm cell’s physical and molecular structure.

How To Improve Chances Of Conception

Despite these, couples, whether one or both is overweight and obese, can still improve their chances of having children. By embarking on a weight-loss journey, through exercise and diet, women can regulate their menstrual cycle and improve their chances of conceiving.

In fact, obese women who have anovulatory infertility (or do not produce eggs), they improve their fertility and increase their chances of conceiving even if they only lost 5 to 10% of the weight.

One of the lesser-known disadvantages of obesity is the impact it has on fertility. Simply put, overweight and obese individuals will find it harder to get pregnant, though they can easily improve their chances.

Experts recommend losing at least 7% of their body weight and adding 150 minutes of moderate exercise every week to promote good health and fertility. Couples who are both overweight are more likely to lose weight together and together can increase their chances of getting pregnant.

Related posts