STIs, pollution, and social attitudes: the hidden causes of infertility

“Having a baby is probably the most important event in most people’s lives and fertility problems cause an immense deal of distress,” says Professor Adam Balen, chairman of the Fertility Education Initiative. Without doubt, infertility can exact a terrible psychological toll on men and women desperate to be parents, resulting in lifelong disappointment. That’s why the news yesterday that a relatively unknown infection that can cause infertility, mycoplasma genitalium (MG), could be the next superbug, has resulted in consternation among healthcare professionals and the public.

But there are a number of other lesser-known causes of infertility that those looking to start a family should be aware of, which can perhaps be divided into infectious, environmental and social causes.

MG often has no symptoms but can lead to pelvic inflammatory disease, which can can cause infertility in women by inflaming the womb and fallopian tubes and its growing resistance to antibiotics is worrying to many sexual and reproductive health doctors. It’s not the only bacterial infection with an increasing immunity to antibiotics that can cause infertility, however.

For the past decade doctors have been warning that tuberculosis is back with a vengeance. Once written off as a disease of the Victorian slums, it has re-emerged in drug-resistant strains which can render women unable to conceive in a similar way to MG.

“Tuberculosis can prevent implantation of the embryo,” explains Professor Simon Fishel, founder of CARE Fertility. “The fallopian tubes have tiny little hairs on them that move the embryo down into the womb. Tuberculosis infection can damage them and the lining of the womb, preventing implantation.”

Chlamydia, one of the most common sexually transmitted infections, is known to cause infertility in women via inflammation of the reproductive organs, but not so well known is it can do the same in men. “It can bind to the sperm and prevent it penetrating the egg and thereby causing a different type of infertility - lack of fertilisation rather than lack of implantation,” explains Fishel. With each episode of chlamydia there’s a one in six chance it will block your tubes and someone with the disease may have no symptoms at all.

Beyond infectious diseases, environmental factors such as pollution can also lead to infertility. Heavy metals, such as lead, can build up in human tissue and cause problems for sperm and egg production, according to Fishel: “Pollutants, whether they’re heavy metals; or endocrine-disruptive [affecting human hormones] chemicals compounds which are prevalent in things like cling-film; or massive amount of oestrogen being flushed down the toilet from women taking the pill are everywhere around us affecting fertility. And they can be very insidious - some of them aren’t flushed out the system very well so they build up to increasingly toxic levels. There is little reason to doubt we live in a toxic environment.”

Not all harmful chemicals that we ingest come to us in the form of pollution, however. Many of them we pay money for due to social pressures - illegal drug use can cause problems, says Professor Balen. “A lot of young men use anabolic steroids for body-building, which enhances their muscles but shrivels their testicles. And cannabis may have a negative effect by causing damage to the genetic integrity of sperm,” he says.

Dr Virginia Beckett, a spokeswoman for the Royal College of Obstetricians and Gynaecologists, says our attitudes to when we can have babies should probably change too.

“I don’t think the fertility community has done itself any favours with promoting egg-freezing to women in the 30+ age bracket,” she says. “We’re giving the impression you can put making a family on hold and if you just freeze your eggs it will be OK. The data suggests egg-freezing is successful for women in their twenties but once you get to your thirties the yield of eggs that you get and the success rates of having a baby delivered are quite low. We need to get across to employers, men and women that if you want to have a family and a reasonable-sized family then you need to start in your twenties.”

And there’s a very simple social reason for low baby counts. We just aren’t going through the process of making them naturally. “The number of people I see who aren’t having sex is growing. Among the professional class it’s worse. I see a lot of other doctors in fertility clinics as patients - undoubtedly one of the factors is that they’re not having sex three or four times a week, which is what you need to give yourself a good chance, because people are working really long hours.

“And they’re getting emails at all times because they're on their smartphone at night instead of having sex with their partner, which is what people used to do. The impact of social media and work bleeding into your home life has been very detrimental for fertility in the western world.”