Effect of Body Weight on Fertility

Understanding the Impact of Body Weight on Fertility

Globally, 2.1 billion adults are overweight – accounting for almost 30% of the world’s population. In 2017-2018, reports indicate that 2 in 3 Australian adults were overweight or obese.

To determine a healthy weight, the healthcare industry often refers to the BMI or Body Mass Index. BMI is the routine measure used to assess whether a person is under or over the ideal body weight. The BMI is calculated as weight (kg) divided by height (m).

A person’s body weight can have a profound impact on their fertility. Men and women who are either under or over their ideal weight have a higher risk of experiencing infertility. Research has shown that excess body weight can lead to problems with the menstrual cycle, infertility, an increased risk of miscarriage and reduced chance of success using fertility treatments such as IVF.

The Impact of Weight on Female Reproduction

Excess body weight can lead to the following conditions:

• Menstrual cycle irregularity
• Infertility
• Increased risk of miscarriage
• Polycystic Ovary Syndrome (PCOS)
• Difficulty achieving a good response to reproductive procedures.

It has been estimated that the chance of pregnancy is 30% less in overweight or obese women. Just a weight reduction of 5%, however, can regulate the female menstrual cycle in over 60% of women.

Obese women who become pregnant are more likely to suffer from

• Hypertension
• Pregnancy induced diabetes
• Urinary infections
• Caesarean section deliveries or assisted deliveries.

Incidence of miscarriage is also higher in obese women.
Conversely, being underweight can also lead to disruptions in the normal menstrual cycle and subsequent fertility problems.

The Impact of Weight on Male Fertility

Excess body weight can lower the levels of testosterone in men which reduces the sperm count. In addition, an apron of fat around the testicles can increase the temperature in this genital area and can also potentially reduce the sperm count.

Stress and Weight Loss

Whilst being in a healthy weight range is proven to increase fertility, it is important to ensure that there is a healthy balance. Excessive exercise and strict calorie counting to facilitate weight loss can put the body under enormous stress. Having high levels of stress can also be a factor for fertility problems.

If you are concerned that your weight could be impacting your fertility, please speak to your GP or make an appointment with Concept Fertility at 08 9382 2388 to discuss this with one of our Fertility Specialists.