Ovarian reserve and female infertility: age, causes and options in the UK

Ovarian reserve is the term clinicians use for the supply of eggs remaining in the ovaries. NICE refers to decreasing ovarian reserve as the reason the chance of a live birth, whether by spontaneous conception or assisted reproduction, falls with advancing age, and discusses it when considering how long to wait before invasive treatment such as IVF.

The NHS says fertility tests can take time and that female fertility decreases with age, so it is best to make an appointment early. It puts the decline in fertility as speeding up when reaching the mid-30s, and advises seeing a GP sooner if you are 36 or over.

Age is the commonest reason. The NHS also describes premature ovarian failure, where the ovaries stop working before the age of 40, as a cause of ovulation problems, and says that chemotherapy can sometimes cause ovarian failure so that the ovaries can no longer function properly. Early or premature menopause can be caused by treatments such as radiotherapy or chemotherapy, certain hormone medicines or surgery to remove the ovaries, and is more likely if it runs in the family, if you started your periods early, if you smoke or if you are underweight.

Other conditions can affect fertility without changing the number of eggs, including problems with ovulation such as PMOS (previously polycystic ovary syndrome), thyroid problems, endometriosis, fibroids, pelvic inflammatory disease and scarring of the fallopian tubes. For 1 in 4 couples the NHS says a cause cannot be identified.

Difficulty conceiving is often the main sign. When the ovaries stop working early, periods can change. The NHS says the main symptom of early or premature menopause is not having your period regularly or periods stopping completely before the age of 45, and that other symptoms can include hot flushes, night sweats, vaginal dryness, poor sleep, low mood or anxiety, reduced sex drive and problems with memory or concentration.

See a GP if you are under 45 and have menopause symptoms, as the NHS says a GP may do blood tests.

The NHS says the GP will ask about your medical and sexual history, how long you have been trying, your periods, previous pregnancies, medicines and lifestyle, and may examine you and refer you for tests. Tests for women include blood tests to check ovulation with a progesterone test, and if periods are irregular, a test of gonadotrophin hormones that stimulate the ovaries to produce eggs. An ultrasound scan can check the ovaries, womb and fallopian tubes, and a chlamydia test is routine. A hysterosalpingogram or laparoscopy may be used where a tubal problem is suspected. Men are offered semen analysis, as fertility problems can affect either or both partners.

The NHS pages I used do not describe a specific ovarian reserve test. Fertility specialists may use additional hormone blood tests or ultrasound assessment of the ovaries, and a specialist team can explain what is appropriate and how much weight to put on the results alongside your age.

The NHS says there are three main types of fertility treatment: medicines, surgical procedures and assisted conception, including intrauterine insemination (IUI) and in vitro fertilisation (IVF). Fertility medicines include clomifene to encourage ovulation, tamoxifen, metformin for PMOS and gonadotrophins. The HFEA says IVF involves suppressing natural hormone production, hormone treatment to boost egg supply, egg collection, mixing eggs and sperm and embryo transfer, that one cycle usually takes four to six weeks, and that success depends on the woman's age and the cause of infertility.

The HFEA also says IVF may be unlikely to succeed for some people, particularly older women or those at risk of premature menopause, and that you should talk to your doctor about your personal chances. If you cannot use your own eggs, the NHS describes treatment with donated eggs, usually by IVF, and says people who donate after 1 April 2005 are not anonymous.

Trying to conceive can be an emotional process, and the NHS says it is important to support each other as much as possible. It encourages both partners to attend the GP. Stress is just one factor that can affect fertility. Making lifestyle changes such as stopping smoking and moderating alcohol, as the GP may recommend, can help overall health.

For early menopause, the NHS lists the Daisy Network for support, and says NHS talking therapies can be accessed without seeing a GP first. The HFEA says preserving fertility is a serious decision with much to consider, and that clinics must offer counselling before treatment.

The NHS says fertility treatment funding varies across the UK and depends on what your local integrated care board offers, but that all patients have the right to be referred to an NHS clinic for the initial investigation. The HFEA says decisions about who can have IVF on the NHS are made locally and that if you pay for IVF the cost varies considerably between clinics and can include extras such as embryo storage. The NHS says the HFEA regulates and inspects all UK clinics providing fertility treatment.

Many people use both: NHS investigation and private treatment cycles, or a private opinion on timing. If you pay privately, check that the clinic is HFEA-licensed and ask for age-specific success rates and a full breakdown of costs.