From NHS Choices

  1. Overview
  2. Causes
  3. Diagnosis
  4. Treatment

Infertility is when a couple cannot get pregnant (conceive) despite having regular unprotected sex.

Around 1 in 7 couples may have difficulty conceiving.

About 84% of couples will conceive naturally within a year if they have regular unprotected sex (every 2 or 3 days).

For couples who have been trying to conceive for more than 3 years without success, the likelihood of getting pregnant naturally within the next year is 1 in 4, or less.

Getting help

Some people get pregnant quickly, but for others it can take longer. It’s a good idea to see a GP if you have not conceived after a year of trying.

Women aged 36 and over, and anyone who’s already aware they may have fertility problems, should see their GP sooner.

They can check for common causes of fertility problems and suggest treatments that could help.

Infertility is usually only diagnosed when a couple have not managed to conceive after a year of trying.

There are 2 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 1 or more pregnancies in the past, but is having difficulty conceiving again

Read more about how infertility is diagnosed.

Treating infertility

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 such as intrauterine insemination (IUI) or IVF

The treatment offered will depend on what’s causing the 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 a GP for advice, and should make sure you choose a clinic that’s licensed by the Human Fertilisation and Embryology Authority (HFEA).

Some treatments for infertility, such as IVF, can cause complications.

For example:

  • multiple pregnancy – if more than 1 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

Read more about how infertility is treated.

What causes infertility?

There are many possible causes of infertility, and fertility problems can affect either partner. But in a quarter of cases it is not possible to identify the cause.

Common causes of infertility include:

  • lack of regular ovulation (the monthly release of an egg)
  • poor quality semen
  • blocked or damaged fallopian tubes
  • endometriosis – where tissue that behaves like the lining of the womb (the endometrium) is found outside the womb

Risk factors

There are also several factors that can affect fertility.

These include:

  • age – fertility declines with age
  • weight – being overweight or obese (having a 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: smoking (including passive smoking) affects your chance of conceiving and can reduce semen quality; read more about quitting smoking
  • alcohol – the safest approach is not to drink alcohol at all to keep risks to your baby to a minimum. Drinking too much alcohol can also affect the quality of sperm (the chief medical officers for the UK recommend adults should drink no more than 14 units of alcohol a week, which should be spread evenly over 3 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.

local guidelines for referral

Local guidelines are outlined below. 

Sub fertility is increasingly common and NHS referrals can be made, however, we can only do so if you meet certain criteria.

Before a referral can be made, we need to carry out some basic investigations in general practice. They are outlined below. This involves blood tests at different times in the cycle, a urine chlamydia test and a recent cervical smear.

Men need to have a seman analysis, this now needs to be done at Hillingdon Hospital.You will need to collect a sample pot and form from reception and follow the instructions as outlined below.


Once we have the results, we can make a referral. All the investigations need to be done in the 3 months before the referral is made.

We can refer you to the local Fertility clinic if .

  • You must be trying to conceive for more than 1 year
  • Women must be aged under 42
  • Women must have a Body Mass Index (BMI) of less than 30 and above 18
  • Have no more than 1 child in your existing relationship.

In order for the hospital to see you, we need to have completed certain tests at our GP practice

For women:

You will need to have 3 blood tests done at certain times in your cycle.

If you take the 1 st day of your period to be Day 1

Please book blood tests on the following days

  • Day 2-4 – Follicle Stmulating Hormone (FSH)
  • Day 8. – Leutinising Hormone
  • Day 21. – Progesterone

We also need to have rubella and Full Blood count on any day.

Prolactin and thyroid test if you are not having periods.

If you have not had a period for several months, we can do some tests, please speak to your doctor

If you are over 25 years of age you will also need to have had a cervical smear test within the last 3 years-please book with the nurse at a time when you are not on your period if you need this

You will also require a test for Chlamydia. If you are having a smear test, ask the nurse to take a swab at the same time. If not you can do a urine test.

It is also worth taking Folic acid tablets 400micrograms once daily as a vitamin supplement to help prevent problems with developing spinal cord

For Men:

You will need to have a sperm test, please speak to your doctor for a pot and form for instructions

When you have both completed your tests, please speak to one of the GPs about the results and we can then send off your referral.

Many thanks for your co-operation, we appreciate it may seem daunting but it is the hospital policy that you have these tests before we can refer you so that you get more time efficient care at the hospital.