If you’ve been trying to conceive for over a year, it might be a good idea to make an appointment with your GP for some investigations. The tests may help determine if there’s an underlying cause of why you’re not getting pregnant. Here we’ll explore the different types of tests you may encounter. 

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. Most commonly, investigations will involve blood tests, an ultrasound and a semen analysis. 

Blood tests:

  • P21 - This test measures progesterone levels to assess if ovulation has taken place. 
  • FSH (follicle stimulating hormone) - This is used to give an indication of ovarian activity. 
  • LH (luteinising hormone) - LH should reach a peak before ovulation, but elevated LH levels can have an abnormal effect on the ovaries. 
  • E2 (oestradiol) - High levels of E2 may suppress other reproductive hormones that are responsible for ovulation, so an elevated E2 could mean that you’re not ovulating each month.
In some cases, your GP may request additional tests like:
  • Prolactin - Elevated levels of prolactin may suppress ovulation so prolactin may be checked if periods are absent.
  • 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 issues.
  • Testosterone -Raised levels of testosterone can disrupt your menstrual cycle and may lead to irregular cycles. 


In addition to blood tests, you may also have a pelvic or transvaginal ultrasound examination to assess your uterus, fallopian tubes and ovaries. This is used to look for signs that your fallopian tubes could be blocked, which could be preventing the eggs from travelling down after ovulation or preventing sperm from reaching the egg. It could also determine if you have any conditions affecting your uterus, like fibroids or endometriosis, as they may have an impact on your chances of conceiving. 

Semen analysis

A semen analysis is performed to check if there are any issues with the sperm, such as a low count or low motility. The results will include:

  • Volume 
  • Sperm concentration (how many there are)
  • Motility (how they move)
  • Morphology (how they look) 

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.