Can Excess Weight Cause Infertility?
Excess weight can affect ovulation in women and sperm quality in men. Even a modest weight loss can improve the chance of pregnancy for many couples.
In this article 5 sections
Yes, excess weight or obesity can be an important cause of infertility. Extra body fat changes the balance of hormones, which can interfere with regular ovulation. However, being overweight does not mean you cannot have a baby; many women conceive naturally. The good news is that even a modest weight loss often improves the chance of pregnancy. In the video, Dr. Sharmin Afroz briefly explains this topic.
01How to tell if your weight is too high
Weight is usually assessed using the body mass index (BMI), which relates weight to height. For South Asian people, health risks can begin at a lower BMI than in some other populations. Waist size also matters, because fat stored around the abdomen has a greater effect on hormones and on how insulin works. Ask your doctor what a healthy weight range is for you.
02How excess weight affects female fertility
- Ovulation problems: fat cells produce extra oestrogen and the body becomes less responsive to insulin (insulin resistance). This disrupts the hormone signals between the brain and the ovaries, so ovulation may become irregular or stop.
- Irregular periods: when ovulation is irregular, periods also become late or irregular.
- Polycystic ovary syndrome (PCOS): excess weight can worsen PCOS symptoms, and PCOS itself makes weight gain more likely.
- Treatment response: with very high weight, fertility treatments such as ovulation medicines or IVF may work less well.
- Miscarriage risk: obesity is linked with a somewhat higher risk of miscarriage.
03A man’s weight matters too
Infertility is not only a woman’s problem. Excess weight in men can lower testosterone and affect sperm count, movement and quality. So when planning a baby, both partners should try to reach and keep a healthy weight.
04The benefits of weight loss and how to start
Studies show that losing just 5 to 10 percent of body weight can make periods more regular in many women and may allow ovulation to return on its own. It also lowers the risk of diabetes, high blood pressure and complications during pregnancy and birth. You can start like this:
- Eat smaller portions of rice, bread and sweets, and more vegetables, lentils, fish and eggs.
- Avoid sugary drinks, fried food and fast food.
- Aim for at least 150 minutes of moderate exercise a week, such as brisk walking.
- Get enough sleep and manage stress.
- Avoid skipping meals or crash diets; make gradual, lasting changes.
Do not take weight-loss medicines or supplements on your own; seek advice from a doctor or dietitian if needed.
When to see a doctor
Alongside weight loss, timely assessment is important, especially as fertility declines with age. See a doctor without delay if:
- You have not conceived after one year of regular intercourse (or six months if you are over 35)
- Your periods are very irregular or have stopped for several months
- You notice excess facial or body hair, acne or dark patches on the neck
- You have diabetes, thyroid disease or high blood pressure
Q & A
Frequently asked questions
There is no fixed number, but losing 5 to 10 percent of body weight helps many women. Your doctor can help you set a realistic target.
Yes, treatment is possible. Weight loss may improve results and reduce pregnancy risks, so doctors often recommend both together.
Yes, excess weight in men can affect hormones and sperm quality. A healthy lifestyle matters for both partners.
Yes, very low body weight can also make ovulation and periods irregular. The aim is a weight within the healthy range.
Article & video by
Dr. Sharmin Afroz
Obstetrics, Gynaecology & Infertility Specialist and Laparoscopic Surgeon
Assistant Professor, Department of Obstetrics & Gynaecology, Anwer Khan Modern Medical College & Hospital.
