Skip to main content

For most people, pregnancy and having babies is ‘women’s business’. Messages about how important it is for pregnant women to stay healthy and avoid things like smoking and alcohol during pregnancy have been around for a long time. But the more we learn about the miracle of having a healthy baby, the more we understand that the health of both women and men before pregnancy is critical for this to happen.

With our focus on men this month, here is what research tells us about how the male partner’s weight can affect the chance of pregnancy happening and the health of the baby.

Most of us know that being overweight or obese is bad for our general health and linked to medical conditions such as diabetes and heart disease. But many are unaware that obesity can lower a man’s fertility. This is likely due to a combination of factors including hormone problems, problems with erections and/or other health conditions linked to obesity.

New research shows that male obesity reduces the chance of the female partner getting pregnant and can affect the future health of the baby. Hot off the press is also evidence that for couples who have IVF treatment, the chance of success is lower for couples where the male partner is obese.

While that’s all very gloomy, the good news is that getting into the healthy weight rage will improve both general health and sperm health. It’s also important to know that men and women are twice as likely to take action to improve their health if their partner does too.

So, a joint approach to eating healthy, losing weight and increasing physical activity by partners who want to have a baby will improve their chances of reaching their goals. Getting support, setting realistic goals and giving yourself enough time to achieve them, learning about nutrition and healthy eating, and exercising regularly increases your chance of losing weight and keeping it off.



Craig, J.R., et al., Obesity, male infertility, and the sperm epigenome. Fertility and Sterility, 2017. 107(4): p. 848-859.

Mushtaq, R., et al., Effect of male body mass index on assisted reproduction treatment outcome: an updated systematic review and meta-analysis. Reproductive BioMedicine Online, 2018. 36(4): p. 459-471.

Weight Men Health Fertility Sperm Conceiving