Infertility is when a couple can't get pregnant (conceive), despite having regular unprotected sex.
Around one in seven couples may have difficulty conceiving. This is approximately 3.5 million people in the UK.
About 84% of couples will conceive naturally within one year if they have regular unprotected sex (every two or three days).
For couples who've been trying to conceive for more than three years without success, the likelihood of getting pregnant naturally within the next year is 25% or less.
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Some women get pregnant quickly, but for others it can take longer. It's a good idea to see your GP if you haven't conceived after one year of trying.
Women aged 36 and over, and anyone who's already aware they may have fertility problems, should see their GP sooner. Your GP can check for common causes of fertility problems and suggest treatments that could help.
Infertility is only usually diagnosed when a couple haven't managed to conceive after one year of trying.
There are two types of infertility:
- primary infertility - where someone who's never conceived a child in the past has difficulty conceiving
- secondary infertility - where someone has had one or more pregnancies in the past, but is having difficulty conceiving again
Read more about how infertility is diagnosed.
Fertility treatments include:
- medical treatment - for lack of regular ovulation
- surgical procedures - such as treatment for endometriosis, repair of the fallopian tubes, or removal of scarring (adhesions) within the womb or abdominal cavity
- assisted conception - this may be intrauterine insemination (IUI) or in-vitro fertilisation (IVF)
The treatment offered will depend on what's causing your fertility problems and what's available from your local clinical commissioning group (CCG).
Private treatment is also available, but it can be expensive and there's no guarantee it will be successful.
It's important to choose a private clinic carefully. You can ask your GP for advice, and should make sure you choose a clinic that's licensed by the Human Fertilisation and Embryology Authority (HFEA).
Read more about how infertility is treated.
Some treatments for infertility, such as IVF, can cause complications.
- multiple pregnancy - if more than one embryo is placed in the womb as part of IVF treatment, there's an increased chance of having twins; this may not seem like a bad thing, but it significantly increases the risk of complications for you and your babies
- ectopic pregnancy - the risk of having an ectopic pregnancy is slightly increased if you have IVF
What causes infertility?
There are many possible causes of infertility, and fertility problems can affect either the man or the woman. However, in a quarter of cases it isn't possible to identify the cause.
In women, common causes of infertility include:
- lack of regular ovulation, the monthly release of an egg
- blocked or damaged fallopian tubes
- endometriosis - where tissue that behaves like the lining of the womb (the endometrium) is found outside the womb
In men, the most common cause of infertility is poor-quality semen.
There are also a number of factors that can affect fertility in both men and women.
- age - female fertility and, to a lesser extent, male fertility decline with age; in women, the biggest decrease in fertility begins during the mid-30s
- weight - being overweight or obese (having a body mass index (BMI) of 30 or over) reduces fertility; in women, being overweight or severely underweight can affect ovulation
- sexually transmitted infections (STIs) - several STIs, including chlamydia, can affect fertility
- smoking - can affect fertility in both sexes: smoking (including passive smoking) affects a woman's chance of conceiving, while in men there's an association between smoking and reduced semen quality; read more about quitting smoking
- alcohol - for women planning to get pregnant, the safest approach is not to drink alcohol at all to keep risks to your baby to a minimum; for men, drinking too much alcohol can affect the quality of sperm (the chief medical officers for the UK recommend men and women should drink no more than 14 units of alcohol a week, which should be spread evenly over three days or more)
- environmental factors - exposure to certain pesticides, solvents and metals has been shown to affect fertility, particularly in men
- stress - can affect your relationship with your partner and cause a loss of sex drive; in severe cases, stress may also affect ovulation and sperm production
There's no evidence to suggest caffeinated drinks, such as tea, coffee and colas, are associated with fertility problems.
To find out more about what you can do to protect your fertility, see:
Infertility can be caused by many different things. For 25% of couples, a cause can't be identified.
This page covers the possible causes of infertility in men and women.
In women, causes include:
In men, causes include:
This page also has information about:
Infertility in women
Infertility is most commonly caused by problems with ovulation, the monthly release of an egg. Some problems stop an egg being released at all, while others prevent an egg being released during some cycles but not others.
Ovulation problems can be a result of:
- polycystic ovary syndrome (PCOS)
- thyroid problems - both an overactive thyroid gland and an underactive thyroid gland can prevent ovulation
- premature ovarian failure - where a woman's ovaries stop working before the age of 40
Scarring from surgery
Pelvic surgery can damage and scar the fallopian tubes, which link the ovaries to the womb.
Cervical surgery can also sometimes cause scarring or shorten the neck of the womb (the cervix).
Cervical mucus problems
When you're ovulating, mucus in your cervix becomes thinner so sperm can swim through it more easily. If there's a problem with the mucus, it can make it harder to conceive.
Non-cancerous growths called fibroids in or around the womb can affect fertility. In some cases, they may prevent a fertilised egg attaching itself to the womb, or they may block a fallopian tube.
Endometriosis is a condition where small pieces of the womb lining (the endometrium) start growing in other places, such as the ovaries. This can damage the ovaries or fallopian tubes and cause fertility problems.
Pelvic inflammatory disease
Pelvic inflammatory disease (PID) is an infection of the upper female genital tract, which includes the womb, fallopian tubes and ovaries.
It's often caused by a sexually transmitted infection (STI). PID can damage and scar the fallopian tubes, making it virtually impossible for an egg to travel down into the womb.
Some women choose to be sterilised if they don't want to have any more children.
Sterilisation involves blocking the fallopian tubes to make it impossible for an egg to travel to the womb. It's rarely reversible - if you do have a sterilisation reversed, you won't necessarily become fertile again.
Medicines and drugs
The side effects of some types of medicines and drugs can affect your fertility.
- non-steroidal anti-inflammatory drugs (NSAIDs) - long-term use or a high dosage of NSAIDs, such as ibuprofen or aspirin, can make it more difficult to conceive
- chemotherapy - medicines used for chemotherapy can sometimes cause ovarian failure, which means your ovaries will no longer be able to function properly
- neuroleptic medicines - antipsychotic medicines often used to treat psychosis; they can sometimes cause missed periods or infertility
- spironolactone - a type of medicine used to treat fluid retention (oedema); fertility should recover around two months after you stop taking spironolactone
Illegal drugs, such as marijuana and cocaine, can seriously affect fertility and make ovulation more difficult.
Infertility in men
Semen and sperm
The most common cause of infertility in men is poor quality semen, the fluid containing sperm that's ejaculated during sex.
Possible reasons for abnormal semen include:
- a lack of sperm - you may have a very low sperm count, or no sperm at all
- sperm that aren't moving properly - this will make it harder for sperm to swim to the egg
- abnormal sperm - sperm can sometimes be an abnormal shape, making it harder for them to move and fertilise an egg
Many cases of abnormal semen are unexplained.
There's a link between increased temperature of the scrotum and reduced semen quality, but it's uncertain whether wearing loose-fitting underwear improves fertility.
The testicles produce and store sperm. If they're damaged, it can seriously affect the quality of your semen.
This can happen as a result of:
- an infection of your testicles
- testicular cancer
- testicular surgery
- a problem with your testicles you were born with (a congenital defect)
- when one or both testicles hasn't descended into the scrotum, the loose sac of skin that contains your testicles (undescended testicles)
- injury to your testicles
Some men choose to have a vasectomy if they don't want children or any more children.
It involves cutting and sealing off the tubes that carry sperm out of your testicles (the vas deferens) so your semen will no longer contain any sperm.
A vasectomy can be reversed, but reversals aren't usually successful.
Some men experience ejaculation problems that can make it difficult for them to release semen during sex (ejaculate).
Hypogonadism is an abnormally low level of testosterone, the male sex hormone involved in making sperm.
It could be caused by a tumour, taking illegal drugs, or Klinefelter syndrome, a rare syndrome where a man is born with an extra female chromosome.
Medicines and drugs
Certain types of medicines can sometimes cause infertility problems.
These medicines are listed below:
- sulfasalazine - an anti-inflammatory medicine used to treat conditions such as Crohn's disease and rheumatoid arthritis; sulfasalazine can decrease the number of sperm, but its effects are temporary and your sperm count should return to normal when you stop taking it
- anabolic steroids - are often used illegally to build muscle and improve athletic performance; long-term abuse of anabolic steroids can reduce sperm count and sperm mobility
- chemotherapy - medicines used in chemotherapy can sometimes severely reduce sperm production
- herbal remedies - some herbal remedies, such as root extracts of the Chinese herb Tripterygium wilfordii, can affect the production of sperm or reduce the size of your testicles
Illegal drugs, such as marijuana and cocaine, can also affect semen quality.
In the UK, unexplained infertility accounts for around 25% of cases of infertility. This is where no cause can be identified in either the woman or man.
If a cause for your fertility problems hasn't been identified, talk to your doctor about the next steps.
The National Institute for Health and Care Excellence (NICE) recommends that women with unexplained infertility who haven't conceived after two years of having regular unprotected sex should be offered IVF treatment.
The NICE guidance has more about unexplained infertility.
Find out more about fertility tests and how problems are diagnosed.
More than 80% of couples where the woman is under 40 will conceive naturally within one year of having regular unprotected sex.
Regular unprotected sex means having sex every two to three days without using contraception.
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When to get medical help
See your GP if you haven't conceived after one year of trying.
You should see your GP sooner if you:
- are a woman aged 36 or over - the decline in fertility speeds up when a woman reaches her mid-30s
- have any reason to be concerned about your fertility - for example, if you've had treatment for cancer or you think you might have had a sexually transmitted infection (STI)
Fertility tests can take time and female fertility decreases with age, so it's best to make an appointment early on.
Your GP will be able to carry out an initial assessment to check things that may be causing your fertility problems and advise you about what to do next.
It's always best for both partners to visit their GP as fertility problems can affect a man or a woman, or sometimes both.
Trying to conceive can be an emotional process, so it's important to support each other as much as possible. Stress is just one factor that can affect fertility.
Questions your doctor may ask
Your GP will ask you about your medical and sexual history.
Previous pregnancies and children
If you're a woman, your GP will want to discuss any previous births and any complications with previous pregnancies. They'll also ask about any miscarriages you've had.
If you're a man, you'll be asked whether you've had any children from previous relationships.
Length of time trying to conceive
Your GP will ask how long you've been trying to conceive.
More than 80% of couples will conceive within one year if:
- the woman is under 40 years of age, and
- they don't use contraception and have regular sex (every two to three days)
Of those who don't conceive in the first year, about half will do so in the second year.
If you're young and healthy and you haven't been trying for a baby for very long, you may be advised to keep trying for a little longer.
You'll be asked how often you have sex and whether you have any difficulties during sex.
You may feel uncomfortable or embarrassed discussing your sex life with your GP, but it's best to be open and honest. If the fertility problem is to do with sex, it might be overcome easily.
Length of time since stopping contraception
You'll be asked about the type of contraception you previously used and when you stopped using it. It can sometimes take a while for certain types of contraception to stop working and this may be affecting your fertility.
Medical history and symptoms
Your GP will want to discuss any medical conditions you have or have had in the past, including sexually transmitted infections (STIs).
If you're a woman, your GP may ask how regular your periods are and whether you experience any bleeding between periods or after sex.
Some medications can affect your fertility. Your GP will ask you about any medication you're taking, and might discuss alternative treatments with you.
You should mention any non-prescription medication you're taking, including herbal medicines.
Several lifestyle factors can affect your fertility. Your GP will want to know:
- if you smoke
- how much you weigh
- how much alcohol you drink
- whether you take any illegal drugs
- if you're stressed
They may recommend making changes to your lifestyle to increase your chances of conceiving.
Read more about:
After asking you questions, your GP may carry out a physical examination or refer you for tests.
If you're a woman, your GP may:
- weigh you to see if you have a healthy body mass index (BMI)
- examine your pelvic area to check for infection, lumps or tenderness, which could be a sign of fibroids, ovarian tumours, endometriosis or pelvic inflammatory disease (PID) - see causes of infertility
If you're a man, your GP may check your:
- testicles to look for any lumps or deformities
- penis to look at its shape and structure, and for any obvious abnormalities
After a physical examination, you may be referred to a specialist infertility team at an NHS hospital or fertility clinic for further tests.
Fertility tests for women
Tests to find out the cause of infertility in women include:
A sample of your blood can be tested for a hormone called progesterone to check whether you're ovulating. The timing of the test is based on how regular your periods are.
If you have irregular periods, you'll be offered a test to measure hormones called gonadotrophins, which stimulate the ovaries to produce eggs.
Chlamydia is an STI that can affect fertility. A swab - similar to a cotton bud, but smaller, soft and rounded - is used to collect some cells from your cervix to test for chlamydia. Alternatively, a urine test may be used.
You'll be prescribed antibiotics if you have chlamydia.
An ultrasound scan can be used to check your ovaries, womb and fallopian tubes. Certain conditions that can affect the womb, such as endometriosis and fibroids, can prevent pregnancy.
A scan can also be used to look for signs that your fallopian tubes - the tubes that connect the ovaries and the womb - may be blocked, which may be stopping eggs travelling along the tubes and into the womb.
If the ultrasound suggests a possible blockage, your doctor will refer you to a specialist to discuss further checks, such as a laparoscopy.
During a transvaginal ultrasound scan, a small ultrasound probe is placed in your vagina. The scan can be used to check the health of your womb and ovaries and for any blockages in your fallopian tubes.
A hysterosalpingo-contrast-ultrasonography is a special type of ultrasound scan sometimes used to check the fallopian tubes.
A small amount of fluid is injected into your womb through a tube put into the neck of your womb (the cervix). Ultrasound is used to look at the fluid as it passes through the fallopian tubes to check for any blockages or abnormalities.
Again, if the test suggests a possible blockage, your doctor will refer you to a specialist to discuss further checks, such as laparoscopy.
A hysterosalpingogram is an X-ray of your womb and fallopian tubes after a special dye has been injected.
It can be used to detect blockages in your fallopian tubes, which may be stopping eggs travelling along the tubes and into your womb.
Laparoscopy (keyhole surgery) involves making a small cut in your lower tummy so a thin tube with a camera at the end (a laparoscope) can be inserted to examine your womb, fallopian tubes and ovaries.
Dye may be injected into your fallopian tubes through your cervix to highlight any blockages in them.
Laparoscopy is usually only used if it's likely that you have a problem - for example, if you've had an episode of pelvic inflammatory disease (PID) in the past, or if your scan suggests a possible blockage of one or both of your tubes.
Fertility tests for men
Tests to find out the cause of infertility in men include:
This is to check for sperm problems, such as a low sperm count or sperm that aren't moving properly.
Read about the different treatments for infertility.
If you have fertility problems, the treatment you're offered will depend on what's causing the problem and what's available from your local clinical commissioning group (CCG).
There are three main types of fertility treatment:
- surgical procedures
- assisted conception - including intrauterine insemination (IUI) and in vitro fertilisation (IVF)
This page also covers:
Fertility medicines are usually prescribed to women as they are mostly used to help with ovulation problems. But, in some cases, they may also be prescribed to men.
Common fertility medicines include:
- clomifene - encourages the monthly release of an egg (ovulation) in women who don't ovulate regularly or who can't ovulate at all
- tamoxifen - an alternative to clomifene that may be offered to women with ovulation problems
- metformin - particularly beneficial for women with polycystic ovary syndrome (PCOS)
- gonadotrophins - can help stimulate ovulation in women, and may also improve fertility in men
- gonadotrophin-releasing hormone and dopamine agonists - other types of medication prescribed to encourage ovulation
Some of these medicines may cause side effects, such as nausea, vomiting, headaches and hot flushes. Speak to your doctor for more information about the possible side effects of specific medicines.
Medication that stimulates the ovaries isn't recommended for women with unexplained infertility because it hasn't been found to increase their chances of getting pregnant.
Surgical procedures that may be used to investigate fertility problems and help with fertility are outlined below.
Fallopian tube surgery
If your fallopian tubes have become blocked or scarred, you may need surgery to repair the tubes. Surgery can be used to break up the scar tissue in your fallopian tubes, making it easier for eggs to pass along them.
The success of surgery will depend on the extent of the damage to your fallopian tubes. Possible complications from tubal surgery include an ectopic pregnancy, when the fertilised egg implants outside the womb.
Endometriosis, fibroids and PCOS
Endometriosis is when parts of the womb lining start growing outside the womb. Laparoscopic surgery is often used for women who have endometriosis to destroy or remove fluid-filled sacs called cysts. It may also be used to remove submucosal fibroids, which are small growths in the womb.
In women with PCOS, a minor surgical procedure called laparoscopic ovarian drilling can be used if ovulation medication hasn't worked. This involves using either heat or a laser to destroy part of the ovary.
Read more about laparoscopy.
Correcting an epididymal blockage and surgery to retrieve sperm
The epididymis is a coil-like structure in the testicles that helps store and transport sperm. Sometimes the epididymis becomes blocked, preventing sperm being ejaculated normally. If this is causing infertility, surgery can be used to correct the blockage.
Surgical extraction of sperm may be an option for men:
- with an obstruction that prevents the release of sperm
- born without the tube that drains the sperm from the testicle (vas deferens)
- who've had a vasectomy or a failed vasectomy reversal
Both operations take a few hours and are carried out under local anaesthetic as outpatient procedures. You'll be advised on the same day about the quality of the tissue or sperm collected. Any sperm will be frozen and placed in storage for use at a later stage.
Intrauterine insemination (IUI)
IUI, also known as artificial insemination, involves inserting sperm into the womb via a fine plastic tube passed through the cervix. Sperm is first collected and washed in a fluid. The best-quality specimens - the fastest moving - are selected.
Read more about IUI.
In vitro fertilisation (IVF)
In IVF, the egg is fertilised outside the body. The woman takes fertility medication to encourage her ovaries to produce more eggs than normal. Eggs are removed from her ovaries and fertilised with sperm in a laboratory. A fertilised egg, called an embryo, is then returned to the woman's womb to grow and develop.
Read more about IVF.
Egg and sperm donation
If you or your partner has an infertility problem, you may be able to receive eggs or sperm from a donor to help you conceive. Treatment with donor eggs is usually carried out using IVF.
Anyone who registered to donate eggs or sperm after April 1 2005 can no longer remain anonymous and has to provide information about their identity.
This is because a child born as a result of donated eggs or sperm is legally entitled to find out the identity of the donor when they become an adult (at age 18).
More on treatments for infertility
Get more information on fertility treatment options on the Human Fertilisation and Embryology Authority (HFEA) website.
Eligibility for fertility treatment on the NHS
Fertility treatment funded by the NHS varies across the UK. Waiting lists for treatment can be very long in some areas.
The eligibility criteria can also vary. Your GP will be able to advise about your eligibility for treatment, or you can contact your local clinical commissioning group (CCG).
If your GP refers you to a specialist for further tests, the NHS will pay for this. All patients have the right to be referred to an NHS clinic for the initial investigation.
If you have an infertility problem, you may want to consider private treatment. This can be expensive, and there's no guarantee of success.
It's important to choose a private clinic carefully. You should find out:
- which clinics are available
- which treatments are offered
- the success rates of treatments
- the length of the waiting list
- the costs
Ask for a personalised, fully costed treatment plan that explains exactly what's included, such as fees, scans and any necessary medication.
Choosing a clinic
If you decide to go private, you can ask your GP for advice. Make sure you choose a clinic licensed by the HFEA. The HFEA is a government organisation that regulates and inspects all UK clinics that provide fertility treatment, including the storage of eggs, sperm or embryos.