Fertility is unique to every individual’s body and is affected by a variety of different elements. Dr Lizle Oosthuizen, a specialist in gynaecology and reproductive medicine at Cape Fertility, describes it as fluid and multifactorial, as it changes as bodies move through life.

For example, “a woman’s fertility at 20 years old is not the same as 30 or 40 years old”, Oosthuizen tells Daily Maverick. 

Oosthuizen also notes how pop culture and media often depict older celebrities falling pregnant, seemingly easily, without any explanation of the process. 

“We see celebrities in their mid-forties falling pregnant and think this is normal, without questioning how. Most women above the age of 43 are going to need egg donation to conceive. Most women after the age of 40 don’t have the luxury of time to not consider IVF. We always think that if we are having periods that we can fall pregnant.”

Female bodies

Current research maintains that individuals with a female reproductive system are born with all of the eggs they will have throughout their lives – about one million. However, by the time one reaches puberty, fewer than half remain, and will continue to decrease over the course of each menstrual cycle and as one ages. 

“As women, we carry these eggs with us our entire lives, until we run out of eggs, which happens before menopause. These eggs are constantly exposed to DNA damage, as are all the cells in our body, but they don’t have the ability to repair themselves,” Oosthuizen explains. 

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“This rate of decline speeds up after 35 years old, and even more so after 40. There is no test we can do to determine egg quality, and it is an assumption based on age. Some women might be genetically predisposed to poorer egg quality, and have poorer eggs at a younger age than expected.

“Every month, a woman’s ovaries will recruit a group of eggs to grow in proportion to the remaining egg reserve. When we are young, we often recruit very high numbers of eggs. As we get older and run low on our egg supply, we start to recruit fewer and fewer every month. All of these eggs start to grow, but only one usually goes on to dominate and ovulate – this is not the best egg, just the one that grew the fastest. The others die out.”

What specialists can estimate, though, is a person’s egg reserve through an ultrasound and a blood test, to determine how ovaries would respond to in vitro fertilisation (IVF), Oosthuizen notes.

However, the test cannot speak to the quality of a person’s eggs, which Oosthuizen explains is the biggest determinant of fertility. 

“We can’t undo or remedy this. With IVF you still have to work with what you have, we can’t magically fix the egg numbers or quality,” she says. 

Genetics are another factor that could influence fertility. This is often linked to genetically inherited medical conditions associated with running out of eggs at a much younger age than expected, Oosthuizen says. For example, being a carrier for a syndrome called Fragile X-associated primary ovarian insufficiency (FXPOI) can cause early menopause or infertility.

A person’s lifestyle can also worsen egg quality and numbers, Oosthuizen says. First, people who smoke experience menopause earlier than non-smokers as ovarian ageing is increased. 

Second, while “you can’t eat your way to better eggs or worse eggs”, weight can also impact fertility. Being overweight can affect hormonal balances in the body, which can make it difficult to conceive, especially with conditions like Polycystic Ovarian Syndrome, Oosthuizen explains, which affects the release of eggs from the ovaries.

A person’s medical history might also affect fertility. 

“Prior ovarian surgery may damage the ovary and reduce the number of eggs [and] any pelvic surgery leaves the risk of scar tissue, which can affect how the tubes function, and therefore if the sperm and egg can actually meet. Chemotherapy and radiation can also severely damage the ovary and may even bring on menopause,” she says. 

Pelvic Inflammatory Disease, caused by untreated sexually transmitted diseases, can also lead to infertility. 

Male bodies

Though people with male reproductive systems do not carry babies, their fertility also plays a role in family planning.

“Men are a bit different to women in that they can continuously produce more sperm. The cycle from start to finish of making sperm takes about three months,” Oosthuizen says. 

“There are some genetic conditions that can result in no sperm, referred to as azoospermia, or very little sperm in the testicles. Chemotherapy or radiation, surgery and injuries (testicular torsion) can result in problems with sperm production. Any man who has a history of undescended testes as a baby is also at risk of some kind of testicular damage.”

There are also lifestyle factors that can play a role in male infertility, as they “damage the DNA integrity in the sperm and contribute to difficult conceiving”, Oosthuizen says. 

She recommends avoiding smoking and drinking, since these can lead to low sperm counts, as well as maintaining a healthy lifestyle, weight and exercise routine. Heat is another consideration, because higher scrotal temperatures can hamper the production of sperm. According to the Mayo Clinic, wearing loose-fitting underwear, sitting less and avoiding saunas and hot tubs can improve sperm count.

“One of the biggest culprits we see is in men who use testosterone supplementation – they will always have problems with their sperm count that can take months to reverse,” Oosthuizen adds

All of these factors together show once again that each body is unique, and therefore no fertility journey is like the other.

“The reason people ask about these things is they always want to know if a certain diet, exercise or supplement will magically improve their fertility. The bottom line is no – there is no magic fix. This is where the assessment comes in,” Oosthuizen says. 

Learning more about one’s own fertility

If a couple or individual is struggling to conceive or would like to conceive, they may approach a fertility specialist to understand how all the above factors come together for them, and what that means for their family planning. 

“The idea is to identify what the potential problems are and to determine the treatment required to get around them,” Oosthuizen explains. 

“[At Cape Fertility] we always start with a full medical and gynaecological history for both partners where a couple presents. We then do a pelvic examination and ultrasound to assess any problems with the uterus or ovaries. We also check for any suggestion of endometriosis (but this is generally not visible on scan), tubal problems, fibroids, or cysts. We count the number of eggs that were told to grow that month, and this is called an antral follicle count.

“We then request blood tests in two groups: the usual pregnancy bloods which are HIV, syphilis, hepatitis screening, rubella immunity and blood group. Then, fertility-related bloods to assess the thyroid function, a few other hormones and the egg reserve blood test, an AMH. 

“We may ask for other tests if we suspect polycystic ovarian syndrome or another medical concern.

“Men will need to do a sperm test, as well as the same infectious blood tests. Once we have all this information we can decide on any extra testing needed, such as checking if the tubes are open or blocked.”

“Once we have a diagnosis, we can then start recommending a course of action for conception.”

Start thinking about family planning young

Even if you’re not ready to have children yet, if you know you will at some point, it is best to start preparing sooner rather than later. 

“My advice to young people would be to use condoms to protect against STIs that cause pelvic damage, to not smoke and to follow as healthy a lifestyle as possible. I would say stay away from drugs and testosterone use,” Oosthuizen recommends. 

“Women should be aware of their declining fertility. It is not fair, but it is the reality. They should consider egg freezing if they are close to 35 and not yet ready for pregnancy. Any couple trying to conceive should know when to seek assistance – within one year if they are under 35 and six months if older than 35. I would also say couples in their forties should act faster.”

All these things considered, each family is unique. 

“There is no magic advice for couples on their journey to baby. Every journey is different with plot twists and unexpected detours,” Oosthuizen says. 

“Build your support network around you, find a doctor who supports and understands you and take it one step at a time. You have to learn to surrender to the process, as we can’t control what the eggs or the ovaries want to do. 

“Most patients are desperate to control something, but the whole fertility journey is out of their hands. All we can do is listen to our patients when they need to be heard, hold their hand when they need the support, and communicate honestly and openly with them.” DM