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Everything you need to know about fertility tests

Updated: Nov 18, 2021

How Fertility Tests Work

How do fertility tests work? Do I need to have fertility tests?

You and your partner want to get pregnant as easily and quickly as possible and have a beautiful healthy baby.

You want to know what to do before you start.

You've heard about a fertility test and want to know more.

This is part 1 of a 3-part series on fertility tests will explain what is involved, what information it can offer you, when and where you can get tested and whether you should test before you start trying to conceive.

Part 1 of this series will answer and discuss:

· What is fertility?

· What is conception?

· What are fertility tests?

· When is fertility testing done?

· How fertility tests work and how fertility is tested.

· Should I have a fertility check before I start trying to conceive?

· Fertility tests on the NHS

Part 2 will discuss fertility tests for women including

· Where can I get fertility testing done?

· How much does a fertility test cost?

· What happens after the tests?

Part 3 will discuss fertility tests for men including

· Where can I get fertility testing done?

· How much does a fertility testing cost?

· What happens after the tests?


Fertility tests: summary points


  • The process of becoming pregnant is complex with many moving parts. A number of factors need to be right including timing of sexual intercourse, the quality of sperm and eggs and correct hormone levels. This can mean that getting pregnant can take longer than expected.

  • Speak to or see a GP or practice nurse for a preconception review consultation, if possible at least 3-6 months before you start trying to conceive and ideally earlier. You will be able to discuss your overal health and receive preconception advice. They can check your blood pressure, weight and height and may arrange blood tests to check your iron levels or vitamin D.

If you have menstrual symptoms e.g. heavy and painful periods and you haven’t had

investigations before your GP can arrange an ultrasound scan or referral to a

gynaecologist.  If you have a known cause of infertility or history of predisposing

factors for infertility e.g. endometriosis, polycystic ovarian syndrome you may require

early referral to the relevant specialist.

  • Your healthcare professional may also recommend taking a prenatal supplement and  suggest lifestyle changes. A dietician can also provide you with more detailed nutrition advice.

  • Over 8 out of 10 couples (80%) under 40 years of age, that have sex twice a week and are not using contraception will become pregnant within 1 year. Over 9 out of 10 couples (90%) will get pregnant within 2 years of trying if they have sex twice a week without using contraception.

  • Over half of women aged under 40 years who have artificial insemination will conceive within 6 cycles. 3 out of 4 women (75%) will conceive within 12 cycles of artificial insemination.

  • Please be aware that getting pregnant can take time. It can take 1-2 years or even longer if you are over 40. If it's taking longer than you expected, it does not mean that something is wrong with you.

  • If you have regular sex, you do not have to do any fertility testing or ovulation tracking initially. Having regular sex every 2-3 days every month, without using condoms or any contraception, can be sufficient to become pregnant assuming that all other factors are aligned. This is the natural way to conceive. It may take up to 1-2 years or may happen much sooner,  but if you understand that it takes time and if you are able to accept it takes time this can relieve some pressure on yourselves.

  • Using methods to help identify the most fertile time during your menstrual cycle i.e. when you are most likely to be ovulating and when your chances of fertilisation are higher are important:

*If you are using artificial insemination to conceive

*If you are not having regular sex and want to get pregnant

*If you want to try to improve how quickly you get pregnant. This is not a proven

fact and insufficient evidence is available to back this particular statement.

If you understand when you are most likely to be ovulating then you can work out

your most fertile time and inseminate or have sex during this timeframe. There are

many tools available to help you do this and they will be discussed in part 2 of the


  • You should be offered clinical assessment and investigations if you have not become pregnant after:

* 6 months of trying to conceive if you are aged 36 or over.

* 12 months if you are 35 years old or younger.

Fertility investigations for females will be discussed in part 2 of this series and for males in part 3 of this series.

What is fertility?

Fertility is defined as the actual production of live offspring (Stedman's Medical Dictionary).

It is the ability to get pregnant and have a baby. The ability to become pregnant without medical intervention requires sexual intercourse or artificial insemination.

Assisted reproductive technology (ART) e.g. IVF is used to help people who have subfertility (delay in the ability to become pregnant) or infertility (people who are unable to become pregnant without assisted reproductive treatments).

The World Health Organization gives several definitions of infertility. The definition most commonly used by healthcare professionals is ‘the inability of a sexually active, non-contracepting (i.e. not using contraception) couple to achieve pregnancy in one year’.

What is conception?

Conception is the act of conceiving or becoming pregnant (Stedmans Medical Dictionary).

In order to conceive naturally, without any assisted intervention (such as IVF), there are a number of events that need to occur in the male and female body. In summary

  • Ovulation and transportation of an egg to the fallopian tube.

  • Production, ejaculation and transport of sperm to the fallopian tube in the female.

  • Fertilisation (fusion of the egg and sperm) to create a cell called a zygote which divides to create a ball of cells called the blastocyst.

  • Implantation of the blastocyst into the uterine lining.

Click here to find a good overview of fertility including female and male factors related to fertility and conception are given. I've also explained in a bit more detail below:

1. At least one egg surrounded by follicles needs to grow and mature. The eggs are found within the ovaries. Follicle stimulating hormone (FSH) is a hormone released by the anterior pituitary gland in the brain. FSH works on the ovaries to encourage one egg and the follicle cells around the egg to grow and mature. The eggs start to produce oestrogen.

2. The egg should be healthy, contain good quality genetic material and therefore be free from chromosomal defects.

3. The egg will move out from the ovary. This is called ovulation. The follicle cells remain inside the ovary. The egg travels down a patent fallopian tube. The fallopian tube must be free from blockages. Ovulation occurs when lutenizing hormone (LH) another hormone produced by the anterior pituitary gland reaches its peak. After ovulation the LH and FSH levels fall.

4. The follicle cells remaining in the ovary form a corpus luteum. The corpus lutem produces progesterone which helps support conception i.e. fertilisation and implantation of the fertilised cells into the lining of the womb.

5. The sperm need to be produced inside the male testes. The sperm should contain good quality genetic material and be free from chromosomal defects.

6. If you have sexual intercourse at the right time; when the male ejaculates, the healthy sperm must travel up into the vagina, through the cervix and into the womb to meet the egg in the fallopian tube. Alternatively, if using IUI, the semen must be inserted at the right time.

If mucus is thick or the womb is hostile to sperm, the sperm will not be able to pass through. After ovulation the egg must be fertilised by a sperm within 12- 24 hours. Sperm can live in the uterus and fallopian tube for up to 5 days. They may reach the fallopian tube within 1 hour or a few days. The chances of fertilisation are best when sperm is already in the fallopian tube when the egg arrives.

7. The sperm and egg meet together, the sperm to fertilises the egg (only one sperm can fertilise a single egg) but if two or more eggs are in the fallopian tube, one separate sperm can fertilise each egg.

8. Once fertilisation occurs the cells from the sperm and egg divide to create a zygote. The cells of the zygote divide and continue to divide while travelling towards the endometrium (lining of the female womb).

9. The endometrium needs to be thick enough and ready to accept the cells which is now called a blastocyst. Cells of the blastocyst produces beta HCG- the pregnancy hormone).

10. The blastocyst embeds and implants into the endometrium. The levels of beta HCG continue to rise.

11. You are pregnant. The beta HCG levels are high enough to be detected and they keep rising as the blastocyst develops into a foetus.

This is just the process of conception!!

At this stage you would take your pregnancy test after a missed period.

You can watch this video below for more information about conception. I selected this video because it is a good starter video; and gives a simple, well-illustrated example of conception.

After conception foetal development continues including development of the heart, lungs, nervous system, gut, skin etc as well as changes to mothers’ body to prepare for birth and feeding the new-born.

This just illustrates how many different embryological and physiological processes are involved in creating a new baby. It’s incredible, fascinating and complex; it’s almost magical!

But the reality is that we can only have tests to analyse a fraction of all that happens in this whole process.

When it comes to becoming pregnant and having a baby; there are a number of tests that can be performed but overall the information provided by fertility testing can not provide all the answers you want; namely your individual chances of getting pregnant and having a baby.