Infertility: causes, symptoms, tests and treatment

The NHS defines infertility as when a couple cannot get pregnant despite having regular unprotected sex. Some people get pregnant quickly, but for others it takes longer. For couples who have been trying for more than 3 years without success, the likelihood of getting pregnant naturally in the next year is 1 in 4, or less.

It is a good idea to see a GP if you have not conceived after a year of trying. The NHS says infertility is usually only diagnosed and treated when a couple have not managed to conceive after 2 years of trying through regular unprotected sex, although women aged 36 and over and anyone already aware of a problem should see their GP sooner.

The main sign is not getting pregnant after a year or more of trying. Many causes have no other symptoms. Some clues can be worth mentioning to a GP, such as irregular or absent periods, which can point to ovulation problems, or painful periods and pain with sex, which can point to endometriosis.

The NHS says problems can affect either partner, so a GP will usually assess both people. A history of sexually transmitted infections, pelvic surgery, pelvic inflammatory disease or testicular problems is relevant.

The NHS says common causes include lack of regular ovulation, poor quality semen, blocked or damaged fallopian tubes and endometriosis, and that in a quarter of cases it is not possible to identify the cause. Unexplained infertility accounts for around 1 in 4 cases in the UK.

Risk factors the NHS lists include age (fertility declines with age), weight (BMI of 30 or over reduces fertility, and being severely underweight can affect ovulation), sexually transmitted infections such as chlamydia, smoking, alcohol (no more than 14 units a week for adults, spread over 3 days or more), exposure to certain pesticides, solvents and metals, and stress.

The NHS says the treatment you are offered depends on the cause and what is available from your local integrated care board (ICB). There are three main types: medicines, surgical procedures and assisted conception.

Medicines for ovulation include clomifene, tamoxifen, metformin (particularly for PMOS), gonadotrophins (which may also improve fertility in men) and gonadotrophin-releasing hormone and dopamine agonists. Side effects can include nausea, vomiting, headaches and hot flushes. The NHS says medicine that stimulates the ovaries is not recommended for women with unexplained infertility because it has not been found to increase their chances.

Surgery may repair blocked or scarred fallopian tubes, treat endometriosis or remove fibroids laparoscopically, perform laparoscopic ovarian drilling in PMOS when ovulation medicine has not worked, or correct an epididymal blockage or retrieve sperm in men.

Assisted conception includes intrauterine insemination (IUI), where sperm is inserted into the womb through a thin tube, and in vitro fertilisation (IVF), where eggs are fertilised in a laboratory and the embryo returned to the womb. A full cycle of IVF takes around 3 to 6 weeks. Donated eggs or sperm can also be used.

The NHS notes that IVF can cause complications such as multiple pregnancy if more than one embryo is placed and a slightly increased risk of ectopic pregnancy. It says there is no evidence that complementary therapies for fertility problems are effective.

The NHS says you may be able to get IVF on the NHS if you are aged 42 or under and eligible. If you are 39 or under you may be eligible for 3 full cycles if you have been trying for at least 2 years, or have tried 12 cycles of artificial insemination (at least 6 using IUI). If you are 40 to 42 you may be eligible for 1 full cycle if the same apply and you have not had IVF before. If tests show you are unlikely to get pregnant without IVF, you should be referred immediately.

Local ICBs make the final decision about funding. Some may only offer IVF if you are under a certain age, are a healthy weight, do not smoke or do not have children already. The NHS says NICE recommends that women with unexplained infertility who have not conceived after 2 years of regular unprotected sex should be offered IVF.

See a GP after a year of trying, or sooner if the woman is 36 or over or you already know of a problem such as endometriosis, irregular periods, a previous pelvic infection or testicular surgery. The GP can check for common causes and suggest treatments, and the NHS says if a GP refers you for tests, the NHS will pay for these.

Healthy steps the NHS lists while trying include keeping to a healthy weight, not smoking, keeping alcohol within limits and addressing stress. Both partners can make these changes.

The NHS says funding for fertility treatment varies across the UK and waiting lists can be long in some areas. All patients have the right to be referred to an NHS clinic for the initial investigation. If you pay the immigration health surcharge you will not be able to have assisted conception such as IVF on the NHS.

Private treatment is also available, but the NHS says it can be expensive and there is no guarantee of success. Make sure the clinic is licensed by the Human Fertilisation and Embryology Authority (HFEA), and ask for a personalised, fully costed treatment plan including success rates, waiting list length and what is included.