Female infertility

There are many factors that can lead to infertility. Factors might be found in a male or female partner. Or both: in over a third of cases, infertility is due to a combination of factors on both sides. This article focuses on factors that affect female infertility.

As a beginners guide to the topic, intersex conditions and possible effects of gender-affirming treatments are not directly discussed in this article.

Vocabulary

Infertility is also known by other names:

The older term sterility isn’t used much any more, because it incorrectly sounds like conception is always impossible. This can lead to upsetting misunderstandings. 

The newer term subfertility is preferred by many doctors, because it makes it clearer that fertility is usually reduced rather than absent.

Sex and Gender: this article uses the words “female” and “male” in their biological sense. To make it as simple as possible to read, it uses “woman” when talking about people with female bodies, and “man” for people with male bodies.  

This article will refer to hormones, organs, and processes which are described in our articles The Menstrual Cycle and Hormones in Pregnancy and Lactation.  It would be useful to read these articles first, or to have them to hand as a useful reference.

Seeking medical help with infertility

Infertility can be caused by many different things, and its causes vary a lot between different couples. When a couple asks for help with infertility, their doctor will first investigate a variety of possible causes.

Sometimes there is a clear reason. For example, if the man does not make sperm, or if the woman has no fallopian tubes. In these examples, the chance of natural conception is extremely low.  

However, it’s more common that a few different factors are identified which combine to create the situation. It is important to realise there may also be unidentified factors. If it’s not possible to work out any clear reasons for the infertility, the term “unexplained infertility” is used.

It’s never possible to be sure that every factor has been identified, and so it is never possible to say that a couple’s infertility is entirely due to one particular factor or person. Instead, the aim is to find identifiable factors (on either or both sides) that can be treated in the hope of conception.

Infertility can be very upsetting for both partners, and so professional advice and counselling is offered to help with the emotional impacts. 

What can cause female infertility?

There are many different conditions women may have that could contribute to a couple’s infertility. And some unknown factors which may lead to a diagnosis of unexplained fertility.

The most common reasons for infertility in women involve problems with the release of the egg, its movement to the uterus, or the embryo’s ability to implant (attach) in the uterus. These are described below.

Doctors also check for normal thyroid function. And to reduce the risk of infertility, it is helpful to avoid excessive stress, have a healthy and stable body weight, avoid smoking and illegal drugs, and to not drink too much alcohol.

Generally, there is a higher risk of female infertility as women get older and approach menopause.

Problems with ovulation (release of the egg)

During a normal menstrual cycle, one mature egg is released from an ovary into the fallopian tube. If eggs are released less often, fertility will be decreased.

If a woman seeking help with infertility is having irregular periods (or none at all), this could be a clue that there is a problem with ovulation. Irregular periods are not at all uncommon, but when combined with known infertility they suggest a possible cause.

Ovulation can be affected by conditions including:

• Polycystic Ovary Syndrome (PCOS), where the ovaries produce too much testosterone
• Hyperprolactinaemia, where the woman has very high levels of the hormone prolactin
• Hypothalamic amenorrhoea, where the woman does not have a menstrual cycle
• Early menopause (before the age of 45 years old), where the ovaries stop producing eggs earlier than they normally would

PCOS is the most common of these. Women with PCOS or early menopause may already know they have a family history of these conditions. If a woman has PCOS, she may also have extra hair growth on her body and face.

If the woman has a low body weight, has been exercising excessively, and suffering from stress, this could be a clue that her infertility is due to hypothalamic amenorrhoea.

How to check ovulation

It’s not possible for a doctor to directly see when an egg is released, but there are clues. These include the levels of hormones in the blood. Hormones are really important in the menstrual cycle and pregnancy.

Follicle Stimulating Hormone (FSH) is an important hormone which helps to regulate the menstrual cycle and can be checked by a blood test. FSH triggers the growth of eggs in the ovaries and gets the eggs ready for ovulation. Follicles (each containing an egg) can also be seen directly by using ultrasound imaging.

Half-way through the menstrual cycle, another hormone is checked: progesterone. If an egg has been released, progesterone levels will be high. This is because after the follicle releases its egg, it changes its function and starts producing progesterone.

Blood is also checked for a hormone called prolactin. Hyperprolactinaemia is a condition where this hormone is found at unexpectedly high levels. High levels of prolactin would normally be a signal that the woman is pregnant (or breastfeeding). The ovaries respond to this signal by slowing or stopping egg maturation and release. Infertility caused by hyperprolactinaemia is usually easy to treat by taking medications to reduce the levels of this hormone. 

Problems with fallopian tubes (movement of the egg)

In a normal menstrual cycle, the egg travels down the fallopian tubes into the uterus. Conception usually happens during this journey. However, if a fallopian tube is missing or blocked, the egg will be less likely (or unable) to become fertilised and reach the uterus.

Fallopian tubes may be blocked by abdominal diseases including Pelvic Inflammatory Disease. Fallopian tubes are also sometimes removed due to complications caused by a fertilised egg attaching somewhere outside the uterus (an ectopic pregnancy). However, there are two ovaries, and two fallopian tubes. Only one set is needed for a pregnancy, so the loss or blockage of one fallopian tube is not a barrier to pregnancy.

Fallopian tubes can be checked in a few different ways.

Firstly, they can be imaged using X-rays or ultrasound. The tubes themselves are hard to see, so a visible dye (for X-ray) or bubbled water (for ultrasound) is squirted into the uterus, from where it flows into the fallopian tubes making them easier to see on the images.  

The area where the fallopian tube enters the uterus can be checked by a camera. Or sometimes keyhole surgery is carried out for a specialist to be able to get a better view of the tubes’ condition.

Women with infertility are also routinely checked for chlamydia, a common sexually transmitted disease. Chlamydia can be treated with antibiotics, but untreated chlamydia is a common cause of Pelvic Inflammatory Disease. Unfortunately, chlamydia usually doesn’t have symptoms itself, so it’s easy to miss an infection. It is found mostly in younger women, and so the NHS recommends that sexually active women under 25 years are tested for it at least once a year. Men can be tested too to help them avoid passing the infection on to their partner. 

Problems in the uterus (implantation of the embryo) 

The fertilised egg (embryo) must attach itself (implant) into the wall of the uterus. If the uterus walls are not in good condition, then it is less likely an embryo will be able to implant.

Conditions that can affect the ability of the embryo to implant include fibroids and endometriosis. Women with these conditions may also have heavy or painful periods, or experience pain during sex.

Fibroids can be diagnosed using ultrasound, by a camera passed up through the vagina, or (less often) keyhole surgery to insert a camera (a laparoscopy).

Endometriosis can be investigated using ultrasound, a camera or MRI scan. But a laparoscopy is needed to confirm a diagnosis.

Treatments for female infertility

Women with infertility are advised to keep as healthy a lifestyle as possible, as this will improve their chances of conception. They should try to keep an ideal body weight, exercise regularly, avoid smoking, and limit how much alcohol they drink.

Other treatments will depend on the contributing causes that have been identified.

Fibroids and endometriosis can be removed or otherwise treated to reduce their effects on fertility.Women with PCOS who are overweight and not ovulating sometimes find that losing even just a bit of weight can help restart ovulation. Medications that reduce their insulin resistance may also help.

If a woman is still not ovulating by herself, hormones including Follicle Stimulating Hormone (FSH) can be given to help encourage her ovaries to produce eggs. This type of treatment is called ovulation induction. It has to be used carefully because it can increase the risk of more than one egg being released, which might result in twins or triplets. Multiple pregnancies carry more risk of complications.

If this doesn’t work, in vitro fertilisation (IVF) might be an option. IVF is a complicated treatment that takes a long time but helps many people conceive. In IVF, a mixed treatment with follicle stimulating hormone and other drugs is given to make more eggs develop than usual. The mature eggs are collected from the woman’s ovaries and fertilised with sperm in a dish in the laboratory. The fertilised eggs develop into tiny balls of cells (embryos), one or two of which are then placed into the woman’s uterus.

IVF can also help if the fallopian tubes are missing or blocked, or there are problems with the man’s sperm. It can be used with donor eggs or sperm, and with surrogates. It can also be used in cases where the causes of infertility are not well understood. You can find out more about IVF in our article In Vitro Fertilisation (IVF).

Despite these many treatment options, couples should always be made aware that - even when there appear to be clear causes for infertility - these treatments don’t always work. It is very difficult to predict the chances of success for any one individual. 

Difficulties and side-effects from treatment

Stimulating the ovaries with hormones like Follicle Stimulating Hormone can sometimes cause the ovaries to become enlarge and leak fluid into the abdomen. This is called ovarian hyperstimulation syndrome, and can cause pain, swelling, nausea and vomiting. These symptoms usually go away without treatment, but in particularly bad cases it might be necessary to drain fluid from the body.

A very significant difficulty of fertility treatment is the complex emotional rollercoaster that couples can experience. Infertility can have long term impacts on the mental health of women and their partner, and on their relationship. IVF especially can be very emotionally stressful as it takes a long time to complete (six to eight weeks for each attempt), with no guarantee of success.

Fertility counselling is recommended to people making difficult decisions about what treatments to try, especially if considering the use of donor egg/sperm or surrogates. Counselling can be of help before, during, and after treatment, as emotional impacts can be long-term.