How excess weight reduces the chance of pregnancy
Being overweight can significantly reduce a woman’s ability to conceive. When BMI rises above 40, the likelihood of becoming pregnant decreases sharply. Fat tissue is not just a passive storage organ, as it produces hormones that disrupt the body’s natural hormonal balance.
This can lead to irregular or even absent menstrual periods, making ovulation unpredictable and lowering fertility. Research shows that overweight women have three times the risk of infertility compared with women of a healthy weight.
PCOS: a major cause of infertility in overweight women
One of the most common reasons for fertility problems is polycystic ovary syndrome (PCOS). Around one in ten women is affected. PCOS causes a hormonal imbalance that interferes with ovulation.
Typical signs include enlarged ovaries with multiple small follicles, raised androgen levels and irregular menstrual periods. Excess body fat makes these symptoms worse, because fat tissue increases the production of hormones such as testosterone, which can further disrupt the cycle.
Reaching a healthy weight before pregnancy also lowers the risk of complications such as gestational diabetes and high blood pressure.
Improving fertility through lifestyle changes
Although PCOS cannot be cured, its symptoms can be managed. Weight loss and regular physical activity often help restore hormonal balance and improve fertility. Losing just 5 to 10% of your body weight can be enough to restore ovulation in many women.
For women with severe obesity (BMI over 35), long-term and stable weight loss is often achieved through weight loss surgery. Many studies show that after losing weight, menstrual periods often return to normal and fertility improves significantly.
Planning a pregnancy after surgery
If you are planning a pregnancy, doctors usually advise waiting 12 to 18 months after weight loss surgery. This gives your weight time to stabilise and your body time to recover, which supports a healthier pregnancy.
Protecting fertility through early action
Excess weight has a clear and measurable effect on female fertility and plays a major role in conditions like PCOS. Young women living with obesity should be encouraged and supported to lose weight to preserve or improve their fertility.
A gynaecological assessment before surgery helps plan for a healthy future pregnancy, including the vitamin and nutritional support your body will need.
