Fertility and a man’s weight
Being overweight, especially significantly so, can affect a man’s fertility. So if you’re a guy, you’re overweight and planning to have a baby in the next year or few years, you might want to act now to lose weight. Start a healthy eating and exercise plan now to increase the odds of your partner (or surrogate) getting pregnant and having a healthy baby.
Being overweight or obese can also have a negative effect on a woman’s fertility, including the time it takes to get pregnant. It can also cause complications for pregnancy and birth.
How can I tell if I’m overweight or obese?
The usual way to find out if you are ‘overweight’ or ‘obese’ is by calculating your body mass index or BMI. This is a weight to height ratio where your weight in kilograms is divided by the square of your height in metres. A BMI calculator – and more information about BMI – are available at the Better Health Channel. A healthy BMI is considered to be between 18.5 and 25. A BMI between 26 and 30 is classified as ‘overweight’ and over 30 as ‘obese’.
The facts about men, weight and fertility
Overweight and obese men have worse sperm quality than men of healthy weight. Being overweight or obese can also cause hormonal changes that reduce fertility and make men less interested in sex. Men who are very overweight are also more likely to have problems getting an erection. Together, these factors reduce the chances of men who are overweight or obese fathering a child.
How can I lose weight?
With a healthy eating plan and regular exercise, you’ll be on your way. The Dieticians Association of Australia website has some excellent information about creating your own healthy diet plan. Visit the Australian Government’s Healthy Weight website for more information about a ‘balanced diet’ and guidelines for how much exercise you need to do to both lose weight and maintain a healthy weight.
Being underweight can also reduce a man’s sperm quality and therefore his fertility. A BMI under 18.5 is classified as ‘underweight’.
Fertility and a woman’s weight
Fertility and being overweight
If you’re trying to get pregnant, or intend to start trying, know that being overweight – especially significantly so – can affect your chances of conceiving and having a healthy baby. If you are overweight and planning to get pregnant in the next year or few years, you might commit to a healthy eating and regular exercise plan. Losing even a few kilos can make a difference. The father’s weight can also affect your chances of getting pregnant and your child’s future health.
How can I tell if I’m ‘overweight’ or ‘obese’?
One common measure of whether a person is ‘overweight’ or ‘obese’ is the body mass index or BMI. You calculate your BMI by dividing your weight in kilograms by the square of your height in metres. The Better Health Channel has a BMI calculator and further information about BMI. A healthy BMI is considered to be between 18.5 and 25. Having a BMI between 26 and 30 is considered ‘overweight’ and over 30 is considered ‘obese’.
The facts about women, weight and fertility
Obesity can affect fertility by causing hormonal imbalances and problems with ovulation, particularly for obese women having their first baby. Obesity is associated with poly-cystic ovary syndrome (PCOS), a common cause of infertility.
If a mother is obese, it increases the risk of pregnancy complications and health problems for the baby. Risks associated with obesity in pregnancy include hypertension, pre-eclampsia , gestational diabetes, infection, thromboembolic disease, need for induction of labour, Caesarean birth and stillbirth.
Babies born to overweight or obese mothers are more likely than those born to healthy-weight mothers to become obese children and adults, and to have more health problems. There is also a higher risk of miscarriage or the baby being stillborn.
The figures about women, weight and fertility
- Women who are overweight or obese have less chance of getting pregnant overall. They are also more likely than women of healthy weight to take more than a year to get pregnant.
- . The risk of pre-eclampsia doubles in overweight women and triples in obese women. Overweight women have twice the risk of gestational (pregnancy-related) diabetes and obese women eight times the risk, compared with women of healthy weight.
- A woman who is obese is more than twice as likely to have a miscarriage as a woman of healthy weight. There is twice the risk that her baby will not survive.
- Infants born to obese women are more likely to be large for their age, need neonatal intensive care or have a congenital abnormality.
How can I lose weight?
With a healthy eating plan and regular exercise, you’ll be on your way to a healthy weight.
The Dieticians Association of Australia website has some excellent information about creating your own healthy diet plan. You can also visit the Australian Government’s Healthy Weight website for more information on a ‘balanced diet’ and guidelines for how much exercise you need to do to both lose weight and maintain a healthy weight.
Being underweight and fertility
Being underweight can also reduce a woman’s fertility. It can cause hormone imbalances that affect ovulation and therefore a woman’s chance of getting pregnant. Compared to healthy weight women, underweight women are more than twice as likely to take more than a year to get pregnant. Having a BMI under 18.5 is considered ‘underweight’.