Fertility-related hormone discussions
Hormone blood tests are often discussed in the context of fertility, menstrual cycle concerns or future family planning. While these tests can provide useful information, they need to be interpreted carefully and always in clinical context.
This page provides GP-reviewed information on commonly discussed fertility-related hormone tests, what they may and may not indicate, and when further assessment or referral may be appropriate.
These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help, please book an appointment with one of our GP’s.
Important scope disclaimer
Hormone tests alone cannot diagnose fertility or infertility.
Normal results do not guarantee fertility, and abnormal results do not automatically mean pregnancy is not possible.
This page is intended to support understanding and discussion, not to replace personalised medical assessment or specialist fertility care.
What this page covers
This page explains:
- common hormone tests discussed in fertility
- what each hormone is involved in
- how results are interpreted in primary care
- limitations of hormone testing
- when further investigation or referral may be needed
Why hormone tests are discussed in fertility
Hormone tests may be considered when there are concerns about:
- irregular or absent periods
- ovulation patterns
- cycle timing
- symptoms of hormonal imbalance
- planning for future pregnancy
- conditions such as PCOS or early menopause
Tests are usually selected based on symptoms rather than done routinely.
Common fertility-related hormone tests
Follicle-stimulating hormone (FSH)
FSH plays a role in stimulating ovarian follicle development.
FSH is sometimes discussed in relation to ovarian function. Levels can vary significantly depending on the timing of the test and stage of the menstrual cycle. A single result does not give a complete picture.
Luteinising hormone (LH)
LH triggers ovulation.
An altered LH to FSH ratio may be seen in conditions such as PCOS, but results must be interpreted alongside symptoms and cycle history.
Oestradiol
Oestradiol is a form of oestrogen involved in cycle regulation and ovulation.
Levels fluctuate throughout the menstrual cycle, so timing of testing is important. Results are interpreted in relation to cycle phase.
Progesterone
Progesterone rises after ovulation.
Progesterone testing is sometimes used to assess whether ovulation has occurred. Timing of the test is critical, and interpretation depends on cycle length and regularity.
Anti-Müllerian hormone (AMH)
AMH reflects the number of follicles present in the ovaries and is often discussed as a marker of ovarian reserve.
Important points about AMH:
- it does not predict natural fertility
- it does not indicate egg quality
- low levels do not mean pregnancy is impossible
- high levels may be seen in PCOS
AMH is best interpreted as part of a broader assessment.
Prolactin
Raised prolactin levels can interfere with ovulation and menstrual cycles.
Prolactin may be tested when periods are absent, irregular or when there are symptoms such as nipple discharge.
Thyroid function tests
Thyroid hormones play an important role in menstrual regularity and ovulation.
Both overactive and underactive thyroid conditions can affect fertility and cycle patterns.
Limitations of fertility hormone testing
Hormone tests have important limitations:
- results fluctuate naturally
- timing within the cycle matters
- results must be interpreted together
- blood tests do not assess egg quality or tubal factors
- partner factors are not assessed by hormone tests
Testing should be guided by symptoms and clinical context rather than used as screening.
When hormone testing may be useful
A GP may consider hormone testing if:
- periods are irregular or absent
- ovulation is uncertain
- symptoms suggest hormonal imbalance
- PCOS is suspected
- early menopause is a concern
- cycles do not return after stopping contraception
Testing is usually one part of a wider assessment.
When referral may be appropriate
Referral to a specialist for further assessment may be considered if:
- cycles remain absent or very irregular
- hormone results are significantly abnormal
- there is concern about early menopause
- fertility concerns persist despite initial assessment
- additional imaging or specialist input is required
A GP can help guide appropriate next steps.
Further Reading and Hub Links
Visit our Women’s Health hub or browse more health topics in the AccessGP Knowledge Base.
If you would like to discuss menstrual cycles, hormone results or future family planning, you can book an online GP appointment with AccessGP.
Last reviewed by Dr Zamiel Hussain, GMC registered GP
Clinical contributor: Dr Tasnimah Miah, Women’s Health Advocate
Updated: 17 December 2025