Protecting your fertility

For both women and men, there are steps to take to protect fertility. Below, we will take a look at at few different factors and how they may impact fertility.

Fertility and sexually transferred infections

Some sexually transmitted infections (STI:s) can decrease a person’s fertility. Chlamydia and gonorrhea are for instance both capable of damaging a woman’s fallopian tubes. In men, the same diseases can lead to low sperm count, especially if they cause an infection of the prostate gland.

To protect your fertility, practice safe sex and get tested for sexually transmitted infections. The risk of long-term fertility problems decreases if the infection is diagnosed and treated early.


Smoking can decrease fertility in both women and men. This includes passive smoking.

Toxins in tobacco can lower the age of menopause by reducing circulating estrogen.

There is a link between smoking and lower quality sperm.


Women who are trying to get pregnant are recommended to refrain from drinking alcohol.

For a man, drinking too much alcohol can lower the quality of his sperm. He is recommended to not drink more than 14 units per week, and those units should be spread evenly over at least three days.

One unit of alcohol equals 10 ml (8 grams) of pure alcohol.


There is no clear evidence of a link between caffeine and fertility problems.


Being underweight or overweight can decrease a woman’s chances of conceiving, especially if her BMI is below 19 or above 30.

Too much or too little body fat can make her periods irregular or stop them completely.

Polycystic ovary syndrome (PCOS) – one cause of infertility in women – is made worse by being overweight.

Being overweight can have a negative impact on the quality and quantity of a man’s sperm, especially if his BMI is above 30.


Being malnourished can decrease a woman’s chances of conceiving.

Being malnourished can decrease the quality of a man’s sperm.


A man’s testicles should ideally be cooler than his core temperature. The ideal temperature for testicles is 34.5 degrees C. If the testicles become warmer than this, it can slow down sperm producing or lead to low-quality sperm.

Examples of things that can make it difficult for the testicles to remain cool enough:

  • Tight underwear
  • Hot baths & showers
  • Sauna
  • Working in a hot environment

Chemicals such as glycol esters

Exposure to certain chemicals, such as the glycol esters found in certain paints, can harm a person’s fertility. Always follow applicable safety procedures in situations that may otherwise subject you to harmful levels of fertility-decreasing chemicals.

Medical treatments

A number of prescription and over-the-counter drugs can interfere with the fertility of men and women. Some treatments will only impact fertility short-term while others may have more long-lasting effects. Radiation, including radiation therapy, can for instance harm a person’s fertility short-term and long-term. The same is true for chemotherapy.

Consult with your physician to find out more about medical treatments and their possible effects on your fertility.

Don’t wait too long

While we can’t change our age, we can take age into account when planning and, if circumstances allow, not wait too long to start the process of trying to get pregnant.

Both women and men are at their most fertile in their early twenties. Still, that doesn’t mean that it is statistically difficult to get pregnant in your late twenties or in your thirties. For heterosexual couples where the woman is under the age of 40, over 80% will conceive naturally within on 12 months of having regular unprotected sex every two to three days.


A woman’s fertility begins to drop sharply after the age of 35, particularly due to a decline in the quality of the eggs released. Around one-third of couples where the woman is over the age of 35 will experience fertility problems if they try to conceive. For a couple where the woman is 40 years or older, it rises to two-thirds.

Many women over the age of 35 can be helped with fertility treatments, but fertility treatments for women aged 35 or older are statistically less likely to result in a live birth as compared to fertility treatments where the woman is younger. Women over the age of 35 are less likely to become pregnant as a result of fertility treatments and if they get pregnant they are more likely to have a miscarriage.


Men’s fertility began to decline gradually from the age of 40. Still, most men are able to father a child without fertility treatment well into their 50s and beyond.