Infertility is when a couple, despite having regular unprotected sex do not conceive (get pregnant).
Figures show that one in six or seven couples have difficulty conceiving.
Around 5% of the population are actually infertile.
Causes of infertility
Complications of infertility
About 85% of couples will conceive naturally within one year if they have regular unprotected sex. For every 100 couples trying to conceive naturally:
- 20 will conceive within one month.
- 70 will conceive within six months.
- 85 will conceive within one year.
- 90 will conceive within 18 months.
- 95 will conceive within two years.
A couple will only be diagnosed as being infertile if they have not managed to have a baby after two years of trying. There are two types of infertility:
- Primary infertility, where someone who has never conceived a child in the past has difficulty conceiving.
- Secondary infertility, where a person has had one or more babies in the past, but is having difficulty conceiving again.
Deciding to seek help
Some women get pregnant very quickly but for others it can take longer. It is a good idea for a couple to visit their GP if they have not conceived after one year of trying.
Women over the age of 35, and anyone who is already aware that they may have fertility problems, should see their GP sooner. The GP may be able to check for common causes of fertility problems, and suggest treatments that could help. If fertility problems are diagnosed, there are many different treatments and procedures that are available.
For couples who have been trying to conceive for more than three years without success, the likelihood of pregnancy occurring within the next year is 25% or less.
Various treatment options are available for infertility, such as intrauterine insemination (IUI) and in-vitro fertilisation (IVF). The success rate of these treatments is 15% for IUI and 29% for IVF, and these decrease as a woman ages.
Causes of infertility
Infertility can be caused by many different factors. Around a third of infertility is due to problems with the woman, and another third is due to problems with the man. In 23% of cases, a cause cannot be identified.
Infertility in women:
Infertility is most commonly caused by problems with ovulation (the monthly release of an egg). Some of these problems stop women releasing eggs at all, and some cause an egg to be released during some cycles, but not others.
Ovulation problems can occur as a result of a number of conditions, listed below.
- Premature ovarian failure, where a woman's ovaries stop working before she is 40.
- Polycystic ovary syndrome (PCOS), a condition that makes it more difficult for your ovaries to produce an egg.
- Thyroid problems. Both an overactive thyroid gland (hyperthyroidism) and an underactive thyroid gland (hypothyroidism) can prevent ovulation.
- Chronic (long-term) conditions. Some chronic conditions, such as cancer, or AIDS, can prevent your ovaries from releasing eggs.
- Cushing's syndrome, a rare hormonal disease that can prevent your ovaries from releasing an egg.
Womb and fallopian tubes
The fallopian tubes are the tubes along which an egg travels from the ovary to the womb. The egg is fertilised as it travels down the fallopian tubes. When it reaches the womb, it is implanted into the womb's lining where it continues to grow.
If the womb or the fallopian tubes are damaged, or stop working, it may be very difficult to conceive naturally. This can occur following a number of factors, outlined below.
Pelvic surgery can sometimes cause damage and scarring to the fallopian tubes.
Cervical surgery can sometimes cause scarring, or shorten the cervix (the neck of the womb).
Cervical mucus defect
When you are ovulating, the mucus in your cervix becomes thinner so that sperm can swim through it more easily. If there is a problem with your mucus,it can make it harder to conceive.
Fibroids are benign (non-cancerous) tumours that grow in, or around, the womb. Submucosal fibroids develop in the muscle beneath the inner lining of the womb wall and grow into the middle of the womb.
Submucosal fibroids can reduce fertility, although exactly how they do this is not yet known. It is possible that a fibroid may block one of your fallopian tubes, or prevent an egg from implanting itself into your womb.
Endometriosis is a condition where small pieces of the womb lining, known as the endometrium, start growing in other places, such as in the fallopian tubes or the ovaries.
This can cause infertility because the new growths form adhesions (sticky areas of tissue) or cysts (fluid-filled sacs) that can block or distort the pelvis. These make it difficult for an egg to be released and become implanted into the womb.
Endometriosis can cause infertility because it can disturb the way that a follicle (fluid-filled space in which an egg develops) matures and releases an egg.
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 is usually 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 do not wish to have any more children.
Sterilisation involves blocking the fallopian tubes to make it impossible for an egg to travel to the womb. This process is rarely reversible, and if you do have a sterilisation reversed, it will not necessarily mean that you will become fertile again.
Medicines and drugs
The side effects of some types of medication and drugs can affect your fertility. These medicines are outlined below.
- 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 for you to conceive.
- Chemotherapy. The medicines that are used for chemotherapy (a treatment for cancer) can sometimes cause ovarian failure, which means that your ovaries will no longer be able to function properly. Ovarian failure can be permanent.
- Neuroleptic medicines are antipsychotic medicines that are often used to treat psychosis. They can sometimes cause missed periods or infertility.
- Spironolactone is a medicine that is used to treat heart failure, and can cause irregular periods and infertility.
- Illegal drugs such as marijuana and cocaine can seriously affect your fertility, making ovulation (the monthly cycle where an egg is released from the ovaries) more difficult. Drugs may also adversely affect the functioning of your fallopian tubes.
Infertility in women is also linked to age. The biggest decrease in fertility begins during the mid thirties. For women who are 35, 95% will get pregnant after three years of having regular unprotected sex. For women who are 38, only 75% will get pregnant after three years of having regular unprotected sex.
Infertility in men:
Abnormal semen (the fluid containing sperm that is ejaculated during sex) is the most common cause of male infertility. Abnormal semen accounts for 75% of male infertility cases. Some possible reasons for abnormal semen are listed below.
- Decreased number of sperm. You may have a very low sperm count, or no sperm at all.
- Decreased sperm mobility. If you have decreased sperm mobility, it will be harder for your sperm to swim to the egg.
- Abnormal sperm. Sometimes sperm can be an abnormal shape, making it harder for them to move and fertilise an egg.
- Many cases of abnormal semen are unexplained, but there are several factors that can affect semen and sperm.
The testicles are responsible for producing and storing sperm. If they are damaged, it can seriously affect the quality of your semen. This may occur if you have, or have had in the past, any of the following:
- an infection of your testicles
- testicular cancer
- testicular surgery
- a congenital defect (a problem with your testicles that you were born with)
- undescended testicles (when one or both of your testicles has not descended into the scrotum)
- a trauma (injury) to your testicles
- a lump in your testicles
Absence of sperm
Your testicles may produce sperm, but it may not reach your semen. The absence of sperm in your semen is known as obstructive azoospermia. This could be due to a blockage in one of the tiny tubes that make up your reproductive system, which may have been caused by an infection or surgery.
A vasectomy is the surgical procedure for male sterilisation. It involves cutting and sealing off the vas deferens (the tubes that carry sperm out of your testicles), so that your semen will no longer contain any sperm. A vasectomy can be reversed, but reversals are not usually successful.
Some men experience ejaculation problems that can make it difficult for them to ejaculate. Other ejaculation problems include:
- retrograde ejaculation, where semen is ejaculated into your bladder
- premature ejaculation, where ejaculation occurs too quickly
Hypogonadism is an abnormally low level of testosterone, the male sex hormone that is involved in making sperm. This could be due to a tumour, taking illegal drugs or Kallman's syndrome (a rare disorder that is caused by a faulty gene).
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 (inflammation of the intestine) and rheumatoid arthritis (painful swelling of the joints). Sulfasalazine can decrease the number of sperm, but its effects are only temporary and your sperm count should return to normal when you stop taking it.
- Anabolic steroids, which are often used illegally to build muscle and improve athletic performance. Long-term use, or abuse, of anabolic steroids can reduce your sperm count and your sperm mobility.
- Chemotherapy. The medicines that are used in chemotherapy can sometimes severely reduce your production of sperm.
- Herbal remedies. Some herbal remedies, such as root extracts of Tripterygium wilfordii (a Chinese herb), can affect the production of sperm or reduce the size of your testicles.
Drinking too much alcohol can damage the quality of your sperm. Guidelines published by the National Institute of Clinical Excellence (NICE) state that if men follow the Department of Health's recommendations of drinking no more than three to four units of alcohol a day, it is unlikely that their fertility will be affected. However, drinking more than this could make it difficult to conceive.
Factors that affect both men and women
As well as factors that specifically affect a man or a woman's fertility, there are also a number of factors that can affect fertility in both men and women. These are outlined below.
Being overweight, or obese, reduces both male and female fertility. In women, being overweight can affect ovulation. Being underweight can also have an impact on fertility, particularly for women, who will not ovulate if they are severely underweight.
Sexually transmitted infections (STIs)
There are several sexually transmitted infections (STIs) that can cause infertility. For example, chlamydia can damage the fallopian tubes in women, and cause swelling and tenderness of the scrotum (the pouch containing the testes) in men.
As well as affecting your general and long-term health, smoking can also adversely affect fertility.
Occupational and environmental factors
Exposure to certain pesticides, metals, and solvents can affect fertility in both men and women.
If either you or your partner are stressed, it may affect your relationship. Stress can reduce libido (sex drive) which in turn can reduce the frequency of sexual intercourse. Severe stress may also affect female ovulation and limit sperm production.
When to see your GP
Around 85% of couples conceive naturally within one year of having regular (every two to three days) unprotected sexual intercourse. You should visit your GP if you have not conceived after one year of trying.
You should visit your GP sooner if:
- you have any reason to be concerned about your fertility, for example, if you have had treatment for cancer
- you are a woman over the age of 35
Fertility testing and investigation can be a lengthy process, and female fertility decreases with age, so it is best to make an appointment early on.
Your GP will be able to give you advice about what to do next, and they will also carry out an initial assessment to investigate factors that may be causing your fertility problems.
It is always best for both partners to visit their GP because fertility problems can affect a man or a woman, or sometimes both partners.
The process of trying to conceive can be a very emotional one, so it is important that you try to support one another as much as possible. Stress is just one of the factors that can affect fertility.
Medical, sexual and social history
When you visit your GP, they will want to find out about your full medical, sexual and social history. This will help them to identify any possible factors that may be causing fertility problems. Your GP may discuss some of the areas below with you.
As fertility in women declines as they get older, your GP will want to know how old you are.
If you are a woman, your GP will ask you if you have given birth previously and, if so, whether there were any complications with your pregnancy. They will also ask about any miscarriages that you may have had.
If you are a man, your GP will ask you whether or not you have had any children from previous relationships.
Length of time trying to conceive
Your GP will ask how long you have been trying to conceive. Around 95% of couples are able to conceive naturally after two years of having unprotected sex. If you are young and healthy, and you have not been trying for a baby for very long, you may be advised to keep trying for a little longer.
Your GP will ask how often you have sex, and whether you have any difficulties during sex. You may feel uncomfortable or embarrassed about discussing your sex life with your GP. However, it is very important to be honest and open. If the fertility problem is to do with sex, it might be overcome easily.
Length of time since stopping contraception
Your GP will ask you about the type of contraception that you were previously using, 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 ask you about any medical conditions that you have, or have had in the past, such as sexually transmitted infections (STIs). If you are a woman, your GP may ask about your periods, such as whether they are regular and if you experience any bleeding between periods or after sex.
The side effects of some medication can affect your fertility. Therefore, your GP will look at any medication that you are taking, and they might discuss alternative treatments with you. You should inform your GP about any non-prescription medication that you are taking, including any herbal medicines.
Several lifestyle factors can affect your fertility. Your GP will ask you:
- if you smoke
- how much you weigh
- how much alcohol you drink
- whether you take any illegal drugs
- if you are stressed
Your GP may discuss ways that you could improve your lifestyle in order to increase your chances of conceiving.
After taking a medical, sexual and social history, your GP may conduct a physical examination or refer you for tests.
Physical examination for women
When carrying out a physical examination your GP may:
- weigh you, to see you whether you have a healthy body mass index (BMI) for your height and build
- examine your pelvic area, to check for vaginal infection, or tenderness, which could be an indication of endometriosis or pelvic inflammatory disease (PID) (see Causes)
After your GP has considered your medical history and carried out a physical examination, they may refer you to a specialist infertility team at an NHS hospital or fertility clinic for some further tests and procedures. These are outlined below.
Tests for women
For women, there a number of tests that can be used to try to establish the cause of infertility.
During a progesterone test, a sample of your blood can be tested for progesterone to check whether you are ovulating. The test is taken seven days before you expect your period to start.
If your periods are irregular, the level of follicle-stimulating hormone (FSH) and luteinising hormone in your blood may be tested. If you have symptoms of an ovulation disorder, such as polycystic ovary syndrome (PCOS), your level of prolactin, another hormone, may also be tested.
Chlamydia is a sexually transmitted infection (STI) that can affect fertility. Your GP will use a swab (similar to a cotton bud, but smaller, soft and rounded) to collect some cells from your cervix to test for chlamydia. If you have chlamydia, you will be prescribed antibiotics to treat it.
Thyroid function test
It is estimated that between 1.3% and 5.1% of infertile women have an abnormal thyroid. If you have any symptoms of a thyroid abnormality, such as weight loss or weight gain, your thyroid gland will be tested to check whether it is functioning properly.
A hysterosalpingography is a type of X-ray that is taken of your womb (uterus) and fallopian tubes after a special dye has been injected. This will detect any abnormalities or defects, such as tumours (growths) or scar tissue.
A hysterosalpingo-contrast-ultrasonography is a type of ultrasound scan. A small amount of fluid will be injected into your womb through a tube that is put into your cervix (the womb opening). High frequency sound waves will be used to create an image of your womb and fallopian tubes to highlight abnormalities.
A laparoscopy involves making a small incision (cut) in your lower abdomen. A thin, tubular microscope called a laparoscope will be used to look more closely at your womb, fallopian tubes and ovaries. Dye may be injected into your fallopian tubes through your cervix in order to highlight any blockages in them.
A laparoscopy is usually only used if there is a strong chance that you have a problem, for example, if you have had an episode of PID in the past.
Examination and tests for men
During a physical examination, your GP may check:
- your testicles, to look for any lumps or deformities
- your penis, to look at its shape and structure, and for any obvious abnormalities
Further testing may include:
- a semen analysis. Your semen will be tested to determine whether you have a low sperm count, low sperm mobility, or abnormal sperm
- a chlamydia test. A sample of your urine will be tested to determine whether you have chlamydia
If you do have chlamydia, your GP will prescribe antibiotics to treat it.
Eligibility for treatment
Fertility treatment that is funded by the NHS varies across the UK. In some areas, the waiting lists for treatment can be very long. The criteria that you must meet to be eligible for treatment can also vary.
Your GP or local primary care trust (PCT) will be able to advise you about your eligibility for treatment (find your local PCT). 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 wish to consider having private treatment. Private treatment can be very expensive and there is no guarantee that it will be successful.
It is 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 is included, such as fees, scans and any medication that is needed.
If you decide to go private, you can ask your GP for advice, and you should make sure that you choose a clinic that is licensed by the Human Fertilisation and Embryology Authority (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.
There are three main types of fertility treatment:
- medicines to assist fertility
- surgical procedures
- assisted conception
The treatment that you are offered will depend on what is causing your fertility problems and what is available from your PCT.
Medicines to assist fertility
The medicines that are often used to assist fertility are listed below. These are usually prescribed for women although, in some cases, they may also be prescribed for men.
- Clomifene helps to encourage ovulation (the monthly release of an egg) in women who do not ovulate regularly or who cannot ovulate at all.
- Tamoxifen is an alternative to clomifene that may be offered to women with ovulation problems.
- Metformin. You may have to take this if you have not responded to clomifene. It is particularly beneficial for women with polycystic ovary syndrome (PCOS) and a body mass index (BMI) of over 25.
- Gonadotrophins. Medicines containing gonadotrophins can help to stimulate ovulation in women, and may also improve fertility in men.
- Gonadotrophin-releasing hormone and dopamine agonists. These are other types of medication that may be prescribed to encourage ovulation in women.
Surgical procedures that may be used to investigate fertility problems and assist with fertility are listed below.
Fallopian tube surgery
If your fallopian tubes have become blocked or scarred, perhaps as a result of pelvic inflammatory disease (PID), you may need to have 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 the surgery will depend on how damaged your fallopian tubes are. One study found 69% of women with the least damaged tubes had a live birth after surgery. Other estimates for live births in women following surgery are 20–50%.
Possible complications from tubal surgery include an ectopic pregnancy (when the fertilised egg implants outside of your womb). Between 8–23% of women may experience an ectopic pregnancy after having surgery on their fallopian tubes.
A laparoscopy involves having a small cut (incision) made in your abdomen. A thin, flexible microscope with a light on the end, called a laparoscope, is then passed through the incision. This type of procedure can be used to look at your internal organs, take samples, and perform small operations.
Laparoscopic surgery is often used for women who have endometriosis (when parts of the womb lining start growing outside of the womb), to destroy, or remove, cysts (fluid-filled sacs). It may also be used to remove submucosal fibroids (small growths in the womb).
In women with PCOS, laparoscopic ovarian drilling can be used if ovulation medication has not worked. This involves using either heat or a laser to destroy part of the ovary.
Correction of an epididymal blockage
The epididymis is a coil-like structure in the testicles that helps to store and transport sperm. Sometimes the epididymis becomes blocked, preventing sperm from being ejaculated normally. If this is causing infertility, surgery to correct the blockage can be performed.
Intrauterine insemination (IUI)
Intrauterine insemination (IUI) involves sperm being placed into the womb through a fine plastic tube. Sperm is collected from the man and washed in a fluid. The best quality specimens (the fastest moving) are selected.
The sperm are passed through a tube that enters the cervix and extends into the womb. This procedure is performed to coincide with ovulation in order to increase the chance of conception. The woman may also be given a low dose of ovary stimulating hormones in order to increase the likelihood of conception.
Some women may experience temporary cramps, that are similar to period cramps, after or during IUI, but other than that the procedure should be painless.
Availability and success
IUI tends to be used when:
- Infertility cannot be explained.
- The man has a low sperm count, or decreased sperm mobility.
- The man is impotent (erectile dysfunction, an inability to maintain an erection), or premature ejaculation (when you ejaculate too quickly).
- The woman has mild endometriosis (where small pieces of the womb lining grow in other places).
Provided that the man's sperm and the woman's tubes are healthy, the success rate for IUI in women who are under 35 is around 15% for each cycle of treatment.
The National Institute for Health and Clinical Excellence (NICE) recommends that couples should be offered up to six cycles of IUI. However, what is available from your PCT, and the criteria that you need to meet, may vary.
In-vitro fertilisation (IVF)
During in-vitro fertilisation (IVF), the fertilisation of the egg occurs outside the body. The woman takes fertility medication to encourage her ovaries to produce more eggs than normal. Eggs are then removed from her ovaries and fertilised with sperm in a laboratory dish. The fertilised embryos are then put back inside the woman's body.
There are several different methods that can be used during IVF. For example, blastocyst transfer is sometimes used for women who are able to make good quality embryos that fail to implant in the womb. Assisted hatching, when the shell of the embryo is made thinner or a small hole is made in the shell, can be used to help the embryo hatch.
Availability and success
NICE recommends that up to three cycles of IVF should be offered to couples if:
- the woman is between 23–39 years of age at the time of treatment, and
- the cause of the couple’s fertility problems has been identified, or
- the couple has had infertility problems for at least three years.
The NHS aims to provide at least one funded cycle of IVF treatment for couples who meet these criteria. It is hoped that in future more cycles will be available on the NHS, although this currently depends on your local primary care trust. Priority is given to couples who do not already have a child living with them.
The success rate for a cycle of IVF is 29% for women who are under 35 years of age. The success rate decreases as the woman’s age increases.
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 either eggs or sperm after 1 April 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 upon reaching the age of 18.
Complications of infertility
Some infertility treatments can cause complications. These are outlined below.
Side effects of medication
Some of the medications that are used to treat infertility can cause side effects. These may include:
- stomach pains
- hot flushes
Ovarian hyperstimulation syndrome
Ovarian hyperstimulation syndrome (OHSS) can occur after taking medicines that stimulate your ovaries, such as clomifene and gonadtrophins, and can develop after a round of in-vitro fertilisation (IVF). OHSS causes your ovaries to swell and produce too many follicles (small fluid-filled sacs in which an egg develops).
Around one-third of women will experience mild OHSS after one cycle of IVF. Less than 10% will develop moderate or severe OHSS after one cycle of IVF.
Mild symptoms may include:
- abdominal pain
- constipation (when you are unable to empty your bowels)
- dark, concentrated urine
Severe OHSS is a potentially life-threatening condition and can lead to:
- thrombosis (a blood clot in an artery or vein)
- liver and kidney dysfunction
- respiratory distress (difficulty breathing)
You should seek medical attention immediately if you experience any of the symptoms of OSHH.
You may need to go to hospital so that your condition can be monitored and you can be treated by healthcare professionals.
Ectopic means in the wrong place. An ectopic pregnancy occurs when the fertilised egg implants outside your womb. More than 95% of ectopic pregnancies occur in the fallopian tubes.
If a fertilised egg implants itself in your fallopian tube and continues to grow, it can result in a miscarriage, and there is a risk of the tube bursting. Signs of an ectopic pregnancy include:
- pains low down in your stomach
- vaginal bleeding
Speak to your GP if you experience either of these symptoms early in your pregnancy.
If you are receiving fertility treatment, your chance of having an ectopic pregnancy is around 4%. This is higher than the usual rate of ectopic pregnancies, which is around 1%. You may be more likely to have an ectopic pregnancy if you have already had problems with your fallopian tubes.
The procedure to extract an egg from an ovary may result in a painful infection developing in your pelvis. However, the risk of a serious infection occurring is very low. For example, there is likely to be less than one serious infection for every 500 procedures that are performed.
Having more than one baby may not seem like a bad thing, but it does significantly increase the risk of developing complications for both you and your children. Multiple pregnancy is the greatest health risk of fertility treatment.
Possible complications of multiple pregnancy include:
- Babies born prematurely or with a low birth weight. This affects 50% of twins and 90% of triplets.
- Your baby dying within the first week of life. The risk of this happening is five times higher for twins, and nine times higher for triplets, than for a single baby.
- Your baby having cerebral palsy (a condition that affects the brain and nervous system). The risk of this happening is five times higher for twins and 18 times higher for triplets than for single babies.
- High blood pressure (hypertension) during pregnancy. This affects up to 25% of women who are carrying more than one baby.
- Developing diabetes during the pregnancy (diabetes is a condition that is caused by too much glucose in the blood). The risk is two to three times higher for women who are carrying more than one baby than it is for those who are carrying a single baby.
In the UK, one in four births after IVF results in twins or triplets. This is higher than the usual rate of multiple pregnancy, which is around one in 80 births.
Infertility can be very stressful and it can put a lot of strain on relationships. It may be helpful for you to join a support group where you can talk through your feelings with others who are experiencing similar problems.
Finding out that you have a fertility problem can be traumatic and many couples find that is it helpful for them to talk to a counsellor. The counsellor will be able to discuss treatment options with you, how they may affect you and the emotional implications. Your GP should be able to refer you to a counsellor as part of your fertility treatment.
Important step in becoming pregnant is ensuring that you are healthy, which you can do by making simple lifestyle changes.
Make sure that you eat a nutritious, balanced diet. It should contain at least five portions of fruit and vegetables a day, carbohydrates such as wholemeal bread and pasta, and lean meat, fish, and pulses for protein. Green, leafy vegetables are high in folic acid, which can help to prevent birth defects.
Women who are underweight or overweight ovulate (release an egg) less regularly, or sometimes not at all, compared to women of a healthy weight.
Therefore ensuring that you maintain a healthy weight will make it much easier to conceive.
Women should aim for a body mass index (BMI) of 19-25 for the best chance of getting pregnant. A BMI of less than 19 may mean that you are ovulating less frequently. If your BMI is over 29, your GP may recommend that you lose weight.
Men with a BMI of over 29 may have reduced fertility, and your GP may recommend that you lose weight. Regular exercise and eating a healthy diet can help you to maintain a suitable weight.
The Department of Health recommends that women should take a daily supplement of 0.4mg of folic acid while they are trying to conceive. If you become pregnant, you should continue taking this until week 12 of the pregnancy. Folic acid helps to protect the unborn baby from problems such as spina bifida (when the baby's spine does not develop properly).
It is very important to stop smoking if you are planning to get pregnant. Smoking is linked to babies with a low birth weight and increased complications during the pregnancy. This advice applies to both women and men because second-hand smoke is bad for unborn babies and young children.
Stress can often affect your fertility because it may lead to you having sex less frequently. For the best chance of becoming pregnant, you need to have sex every two to three days. Talk to your partner if you are feeling stressed and consider using counselling (talking therapy). You may also find regular exercise helpful.
The Department of Health (DH) recommends that women should not drink alcohol while they are trying to conceive. Studies have shown that alcohol can seriously damage a baby's development.
If you decide to drink during pregnancy, you should limit your intake to one to two units of alcohol, once or twice a week, and you should avoid getting drunk.
Men should not drink more than the DH's recommendation of three to four units of alcohol a day. Drinking more than this can reduce your sperm quality. One unit of alcohol is approximately half a pint of normal strength lager, a small glass of wine or a 25ml measure of spirits.
Medicines and drugs
Illegal drugs such as marijuana or cocaine can affect fertility, and can seriously damage the development of your baby if you fall pregnant. You should therefore avoid using them. You should also avoid using some prescription medicines if you are trying to get pregnant. Ask your GP for further advice.
Health checks and tests for women
Make sure that you are up-to-date with your cervical screening tests (smear tests). You need to have one every three to five years depending on your age.
You should also visit your local sexual health clinic (GUM clinic) to make sure that you do not have any sexually transmitted infections (STIs). Infections such as chlamydia may not have any symptoms but can cause infertility if they are left untreated.
Speak to your GP if you are planning a pregnancy. They may recommend that you have some additional tests, such as a test for rubella (German measles). You still need to be tested for this even if you have previously had the vaccination, because it can cause serious birth defects in unborn babies.
You may also be tested for the varicella-zoster virus unless you have a definite history of chickenpox or shingles.
If there is a history of genetic conditions in your family, such as cystic fibrosis (a condition that makes the internal bodily secretions thick and sticky) or Down's syndrome (a condition that affects a person's physical appearance and their ability to learn and develop mentally), you should ask your GP about genetic testing.