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. Being underweight can also reduce a woman’s fertility. If you are planning to get pregnant in the next year or few years, healthy eating and regular exercise can boost your fertility.
Being overweight affects your chances of conceiving and having a healthy baby.
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.
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 24.9. Having a BMI between 25 and 29.9 is considered ‘overweight’ and a BMI over 30 is considered ‘obese’.
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 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’.
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. PCOS is a common hormonal condition especially in infertile women, affecting up to one in five women of reproductive age. Early diagnosis, living a healthy lifestyle and treatment can help optimise fertility.
Find out more about PCOS
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 miscarriage, hypertension, pre-eclampsia , gestational diabetes, infection, blood clotting, 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.
For women with diabetes, it is especially important to plan for pregnancy. If possible, it is recommended to review your diabetes and your general health with your doctor, at least three to six months before trying to conceive. For more information on how to manage diabetes before and during pregnancy visit the National Diabetes Services Scheme (NDSS) Pregnancy & Diabetes website.
"Obesity doesn’t affect a woman’s chances of getting pregnant."
Obesity reduces a woman’s chances of conceiving and having a healthy baby.
Obesity can cause hormonal imbalances that trigger problems with ovulation and the menstrual cycle. Obese women take longer to conceive than women in the healthy weight range and when they do conceive they have a higher risk of pregnancy complications such as miscarriage, diabetes and premature birth.
Introducing ‘Leanne’ and ‘Tom’, the couple in this Fertility Coalition’s Fertility Factors video. Leanne and Tom were couch potatoes whose love life left a lot to be desired.
These fertility fact sheets have been developed by the Fertility Coalition in association with the Fertility Society of Australia’s Preconception Health Special Interest Group. They are aimed at health professionals so they are only to be read by those keen on the science of it all!