Fertility Tests

If you’ve been trying to conceive for over a year, it would be a good idea to make an appointment with your GP for some investigations. These fertility tests may help determine if there’s an underlying cause of why you’re not getting pregnant. Based on the results of your tests, your GP should be able to advise you on your next steps, in order to help you when trying to conceive. Here we’ll explore the different types of tests you may encounter through your GP. There are different tests available to determine male factor infertility, female factor infertility and general infertility.

What do GPs test for?

Your GP will ask you about your menstrual cycle, your medical history, if you take any medications, how long you’ve been trying to conceive and may ask specific questions about the timing of when you have sex. These questions will help your doctor determine what investigations may be most useful to perform. Most commonly, it will involve blood tests to establish if you’re ovulating, an ultrasound to assess your uterus, fallopian tubes and ovaries and a semen analysis which will show the quantity and quality of semen and sperm.

Fertility tests at your GP

Initial fertility investigations may involve the following blood tests:

  • P21 or progesterone test. This is a blood test that is performed in the middle of the luteal phase, which is after ovulation and before your period begins. The test is scheduled for 7 days before your period begins, so the timing is based on the length of your cycle. In a 28 day cycle, this test would commonly be performed on day 21. The test measures progesterone levels to assess if ovulation has taken place1
  • FSH (follicle stimulating hormone. FSH stimulates the growth and production of eggs in the first part of the menstrual cycle. This test may be used to give an indication of the ovarian reserve. 
  • LH (luteinising hormone). LH should reach a peak before ovulation, but elevated LH levels can have an abnormal effect on the ovaries2
  • E2 (oestradiol). High levels of oestradiol may suppress other reproductive hormones that are responsible for ovulation, so an elevated E2 could mean that you’re not ovulating each month.

What additional fertility tests might my GP arrange?

  • Prolactin. Elevated levels of prolactin may suppress ovulation so prolactin may be checked if periods are absent (amenorrhea)2.
  • TSH (thyroid stimulating hormone). Both an overactive and an underactive thyroid gland can have an impact on ovulation and measuring TSH levels would give an indication if this is the cause of any fertility issues3
  • Testosterone. Raised levels of testosterone can disrupt your menstrual cycle and may lead to irregular cycles. In men, low levels of testosterone can impact sperm production4

Testing for male factor infertility

A semen analysis is performed to check if there are any issues with the sperm, such as a low count or low motility (movement of the sperm) which could be contributing to male factor infertility. Laboratories that analyse semen samples use methods and reference values in accordance with the most recent World Health Organisation laboratory manual7. The results will include:

  • semen volume (1.5ml or more)
  • sperm concentration (15 million sperm or more)
  • sperm count/total number of sperm number (39 million sperm or more)
  • sperm motility (40% or more moving sperm)
  • sperm morphology (4% or more normal forms) 

If the result comes back abnormal this is usually repeated in 3 months.

Learn more about fertility tests


  1. Polycystic ovary syndrome – Causes – NHS causes of infertility – NHS 
  2. Polycystic ovary syndrome – Diagnosis – NHS diagnosis of infertility – NHS
  3. Semen analysis information : University College London Hospitals 
  4. Tests for women | Information for the public | Fertility problems: assessment and treatment | Guidance | NICE 
  5. Getting Started – IVF