What causes infertility in women? All your questions answered

Fertility can often feel like a bit of a mystery, and you might not give it much thought until you decide you’re ready to start trying for a baby. But whether or not you’ve made that all-important decision, it can be useful to know the facts when it comes to the causes of female infertility.

Infertility sounds like a daunting word, but it’s a term used to describe having trouble conceiving, which is perhaps more common than you might think. Infertility is thought to affect about 19% of reproductive-aged women and 9% of men in the US. It’s estimated that around 1 in 7 couples could have trouble conceiving, which can be an incredibly difficult and stressful experience. However, it’s important to remember that there are numerous treatment options available to help with fertility, and research shows that every fifth couple diagnosed with infertility will go on to conceive without needing any treatment at all. So try to keep that in mind if you’re struggling to conceive.

But what are some of the risk factors and causes of female infertility specifically? We take a closer look at the research and speak to Dr. Ruth Arumala, obstetrician and gynecologist, Texas, US, for some answers.

What is female infertility?

Before we get started, let’s take a quick biology lesson on what infertility involves. According to the World Health Organization, infertility is “a disease of the male or female reproductive system defined by the failure to achieve a pregnancy after 12 months or more of regular, unprotected sexual intercourse.” 

So essentially, infertility occurs when there is a problem with one (or more) of the stages of the reproductive process. This means that in order for a pregnancy to occur, the following stages all have to happen correctly:

• A mature egg is released from either the left or right ovary. (This is known as ovulation.)
• This egg travels into either the left or right uterine (fallopian) tube.
• A sperm swims through the cervix and uterus and enters the correct uterine tube, and then fertilizes the egg.
• This fertilized egg then moves from the uterine tube into the uterus.
• Finally, the fertilized egg implants in the uterus and grows into a fetus.

In females specifically, there are a number of factors that can affect this process, and we’ll take a closer look at these later on in this article. But it’s important to remember that there are many other causes of infertility — in fact, infertility due to female factors accounts for only one-third of infertile couples. Male factors account for another third, while a combination of male and female factors, or an unknown problem, accounts for the final third. So don’t blame yourself if you initially struggle to conceive, as numerous factors could be at play. And remember, even if your fertility issues are found to be linked specifically to you and your body, try not to be too hard on yourself, as it’s something that’s often totally out of your control.

What are the types of female infertility?

There are two types of female infertility to be aware of: primary infertility and secondary infertility. 

• Primary infertility refers to a struggle to conceive in those who have never been pregnant before. 
• Secondary infertility, on the other hand, applies to those who are struggling to conceive after having had at least one successful pregnancy.

In both cases, infertility is classed as conception not occurring after a year of unprotected sex (without contraception). 

Causes of infertility in women

Fertility problems in women are most commonly linked with ovulation, specifically infrequent ovulation or not ovulating at all. Remember, ovulation is the moment a mature egg is released from one of your ovaries, which is a crucial step for getting pregnant. Let’s take a closer look at the ovulation disorders that can be linked with fertility, as well as the causes of female infertility that don’t occur due to issues with ovulation. And remember, if you’re concerned about your fertility, always speak to your doctor for reassurance and tailored advice.

Ovulation disorders

The following ovulation disorders could affect female fertility:

• Polycystic ovary syndrome (PCOS): An imbalance in hormone levels can cause a number of issues, including less frequent periods and the development of multiple small ovarian cysts, both of which are linked to infertility. 
• Primary ovarian insufficiency, also known as premature ovarian failure: A lack of normal functioning of the ovaries in women under 40 can cause difficulties in getting pregnant. 
• Hypothalamic dysfunction: Follicle-stimulating hormone and luteinizing hormone both work to kick-start ovulation each month. These hormones are produced in the pituitary gland, and if their production is disrupted, this can alter ovulation, affecting the ability to conceive. 
• Too much prolactin: In certain cases, and due to certain conditions, the pituitary gland can also produce too much of another hormone called prolactin, which can also affect infertility.
• Issues with the thyroid gland: If your thyroid gland is either underactive or overactive, it could affect ovulation and make it trickier to conceive.

If you think you might have one of these disorders, be sure to speak to your doctor. They can run some fertility tests to see if an ovulation disorder, or any other disorder or problem, could be contributing to any fertility issues.

Other causes of female infertility

Some of the other causes of female infertility can include the following:

• Endometriosis: It’s thought that tissue growing in the ovaries or fallopian tubes due to endometriosis might cause damage that could lead to infertility.
• Damage to the uterine tubes: If the uterine tubes are damaged or blocked, it can be harder (or not possible) for the sperm to reach the egg or for the fertilized egg to move into the uterus for implantation, meaning that a pregnancy cannot occur. This can be caused by pelvic inflammatory disease (an infection of the uterine tubes and uterus) or any previous surgery you might have had in this area.
• Unexplained infertility: Sometimes, a cause for infertility might not be found. This can be difficult news to hear, but try not to give up hope. Remember that the unknown issue could correct itself in time. In fact, research has found that 13% to 15% of couples with unexplained infertility will conceive without treatment within a year.
• Ovarian cysts: While ovarian cysts don’t technically stop you from getting pregnant, they can be problematic in that they can make it more difficult for you to conceive. If surgery is required, a doctor will take steps to try and preserve your fertility as much as possible.
• Certain drugs: Taking certain drugs, such as long-term use of ibuprofen or aspirin or drugs used in chemotherapy, could have a negative impact on your ability to conceive. If you have any questions or concerns, always reach out to your doctor.

There are also a number of cervical and uterine issues that could cause female infertility. These include: 

• Fibroids (non-cancerous growths that develop in or around the womb): These could block the uterine tubes or affect implantation, but it’s important to note that many women with fibroids can become pregnant without any issues.
• Cervical mucus problems: During ovulation, sperm relies on a thinner consistency of mucus to be able to swim. Without these conditions, it can’t travel to where it needs to go in order to fertilize an egg.
• Cervical stenosis: This is a narrowing of the cervix, which could happen due to damage to the cervix or an inherited genetic issue. A narrow cervix can affect conception and pregnancy.
• Problems with the uterus: There could also be problems with the uterus, such as an unusual shape. 

As we’ve seen, there are a lot of issues that could cause female infertility. If you think you might be affected by one of these issues, try not to panic. Always speak to your doctor in the first instance, and they can check you over and run any necessary tests. Remember that there are also many treatment options available for the above issues and conditions, so try not to give up hope if you are diagnosed with any of them, and seek out any support you need from your loved ones.

Risk factors for infertility

Now that we know the causes of female infertility, what are some of the main risk factors that could slightly increase your chances of fertility issues?

Age

Experts advise that your fertility starts to gradually reduce by the age of 30, with this decline speeding up as you move past your mid-30s.“We have a finite number of eggs that reduce each month, and the quality and quantity of them drop drastically after 35,” explains Dr. Arumala. This might sound frightening if you are past your mid-30s and trying to conceive. But it’s worth keeping in mind that while women in their 20s to early 30s have a 25% chance of getting pregnant each month while trying to conceive, women in their 40s still have a 10% chance of pregnancy each month. And remember that there are treatment options available to help if you do struggle. 

You could also consider the option of egg freezing if you think you might want to get pregnant at a later stage but aren’t ready to do so yet. Many people make this decision for perfectly understandable reasons — after all, having children is a huge commitment. However, it can be worth doing this sooner rather than later if you’re able to. As Dr. Arumala points out: “Planning to use or preserve eggs while they are still present and viable is important.”

Smoking

There is evidence to suggest that smoking can negatively impact a person’s ability to conceive, as well as lead to complications in pregnancy and reproductive function. If you are considering trying to conceive or beginning any kind of fertility treatment, it could be a good idea to seek support in giving it up.

Weight

The links between weight and female infertility are complex, but evidence suggests that being either overweight or underweight can affect fertility. “If your body weight is too low or too high, this puts you at risk of not ovulating,” explains Dr. Arumala. In addition, Dr. Arumala stresses the importance of good nutrition and a balanced diet. “An adequate amount of vitamins and minerals is essential for the proper development and function of the egg and sperm,” she notes. If you think you might need to adjust your diet, always speak to your doctor for advice first.

Alcohol

There is mixed evidence of a relationship between alcohol consumption and fertility, but experts believe that drinking an excessive amount of alcohol could have a negative impact on fertility. So if you think you’re ready to start trying to conceive, you might want to consider cutting down the amount you drink as part of your preparation.

Stress

Researchers aren’t entirely sure whether stress can cause infertility, but it’s clear that infertility itself can cause stress. A 2018 study found that women with a higher level of molecules associated with stress in their bloodstream were less likely to be successful after a cycle of in vitro fertilization (IVF). There’s no doubt that struggling to conceive or going through a procedure like IVF can be stressful in itself, but try to stay calm and relaxed if you can.

Myths about the causes of female infertility

We’ve probably all heard a few myths about female infertility, especially when it comes down to what can cause it to occur. Let’s take a look at some of these and do some handy myth-busting while we’re at it.

• Genetics: While there is no “infertility gene” in women, some conditions linked with infertility do run in families. For example, premature ovarian failure and PCOS are two reproductive disorders that seem to be commonly passed on genetically. 
• Birth control: Thankfully, there is no evidence to suggest that birth control contributes to infertility once a person stops taking it, regardless of how long they were on it. There is also no evidence to suggest it delays fertility in any significant way.

What can be done to lower your risk of infertility?

When asked what people can do to lower their risk of infertility, Dr. Arumala advises that “Addressing any underlying medical issues, managing stress levels, and not smoking are all important things to consider.” Essentially, looking after both your physical and mental health as best you can is a great place to start when looking to boost your fertility. 

But remember: a lot of the causes of infertility can’t be avoided or maintained through lifestyle tweaks alone, so never blame yourself if you do experience infertility.

Treatments for female infertility

As we’ve mentioned, there are numerous treatment options available for female infertility. You can find out more about these options here, but generally, they include:

• Medication
• Surgery
• Reproductive assistance, such as IVF

If you decide to take the step of getting infertility treatment, be sure to take all the time you need to explore your options and choose the one that’s best for you. Ask your doctor any questions that come to mind — after all, they should have all the answers! You can also find out more about female infertility signs here.

When to see a doctor

If you are under the age of 35 and still trying to conceive after a year of regular unprotected sex, it’s best to speak to your doctor to rule out any underlying conditions and make a plan going forward. If you’re over the age of 35, it’s best to speak to your doctor after six months of trying without any luck. If you’re over the age of 40, it’s a good idea to reach out to a doctor before trying to conceive. This may feel like a scary moment, but remember that your doctor is there to help you in any way they can, and they should also have a lot of useful knowledge to share with you.

It could also be a good idea to speak to your doctor if your periods are irregular. “If you’re not experiencing regular periods that are 21 to 35 days apart and lasting three to seven days, this should also be investigated,” adds Dr. Arumala. However, remember that menstrual irregularities can be caused by a number of factors aside from fertility issues, and your periods will also naturally fluctuate throughout your lifetime. So try not to panic if you do notice that your periods are irregular, and speak to your doctor about any tests or investigations that could help. And don’t forget that you can track your periods and keep an eye on any changes using an app like Flo.

The takeaway: What causes infertility in women?

Female infertility refers specifically to difficulty conceiving as a result of an issue with the female reproductive system. Being diagnosed with female infertility can be incredibly difficult news to hear. Try not to blame yourself or your body, as more often than not, female infertility occurs for reasons that are outside of your control.  

The causes of female infertility are most commonly linked with ovulation problems, but there are numerous other reasons why you might struggle to conceive. While this can be an undeniably stressful experience, remember that there are numerous treatment options available. Experts say that even couples diagnosed with infertility can sometimes go on to have children without needing any treatment at all.

If you’re worried you might be experiencing infertility in some way, it’s always best to speak to your doctor so they can help you rule out or manage any underlying conditions with you or your sexual partner. The earlier you address things, the quicker your doctor might be able to help you on your journey to trying to conceive.