Male Hormones and Fertility
How can a pituitary condition affect
male hormones and fertility?
The pituitary gland plays an important role in controlling the testes and male reproductive function.
Two pituitary hormones — luteinising hormone (LH) and follicle-stimulating hormone (FSH), are known as gonadotrophins. They work together to regulate testosterone production and sperm production.
When the pituitary gland does not produce enough LH and FSH, this can result in secondary (central) hypogonadism. This can affect testosterone levels, sexual function, sperm production and fertility.
The impact varies from person to person and depends on the underlying pituitary condition and the extent of hormone deficiency.
What do LH and FSH do?
Luteinising hormone (LH)
LH stimulates specialised cells in the testes to produce testosterone, the main male sex hormone.
Testosterone is important for:
Sexual development during puberty
Development of male physical characteristics
Maintaining muscle mass and strength
Maintaining bone health
Energy and general wellbeing
Sexual desire (libido)
Supporting normal sexual function
Follicle-stimulating hormone (FSH)
FSH acts on cells within the testes that are involved in sperm production.
A deficiency of FSH can therefore reduce sperm production and affect fertility.
For fertility to occur naturally, semen needs to contain an adequate number of healthy, normally functioning sperm.
What is hypogonadism?
Hypogonadism occurs when the body does not produce enough testosterone or is unable to produce sufficient amounts of the hormones required for normal reproductive function.
When the cause is a problem with the pituitary gland or hypothalamus, it is known as secondary or central hypogonadism.
In men with a pituitary condition, low testosterone may occur because the pituitary is not producing enough LH and FSH to properly stimulate the testes.
The Endocrine Society recommends assessing testosterone together with LH and FSH when central hypogonadism is suspected. Testosterone deficiency should be diagnosed using appropriate blood testing together with relevant symptoms and signs.
What can cause pituitary-related hypogonadism?
A number of pituitary and hypothalamic conditions can interfere with the production of LH and FSH.
These can include:
Pituitary adenomas and other pituitary tumours
Hypopituitarism
Pituitary surgery
Radiotherapy affecting the pituitary region
Head injuries or other damage affecting the pituitary or hypothalamus
Certain congenital or genetic conditions
Conditions affecting the hypothalamus
Most pituitary adenomas are benign (non-cancerous), although they can interfere with normal pituitary function or compress surrounding structures.
Treatment for a pituitary tumour, including surgery or radiotherapy, can also sometimes affect hormone production.
Kallmann Syndrome
Kallmann Syndrome is a rare condition in which the hypothalamus does not produce or release sufficient gonadotrophin-releasing hormone (GnRH).
Without adequate GnRH stimulation, the pituitary gland does not release enough LH and FSH.
Kallmann Syndrome is often associated with a reduced or absent sense of smell (anosmia).
Because the condition is usually present from birth, it may result in delayed or incomplete puberty. Some males may also have a smaller penis or undescended testes.
Kallmann Syndrome has a genetic basis and is different from hypogonadism caused by an acquired pituitary condition.
What are the effects of low LH and FSH?
The effects can vary considerably between individuals.
Fertility
Low FSH and LH can reduce sperm production and testosterone production.
This may result in:
A low sperm count
Reduced sperm production
Very low sperm production or, in some cases, no sperm in the semen
Difficulty conceiving naturally
The HSE recognises hormonal problems, including hypogonadism, as one possible cause of male fertility problems. Fertility assessment may include semen analysis and, where appropriate, hormone testing such as testosterone, LH and FSH.
Sexual function
Low testosterone can contribute to:
Reduced sexual desire (libido)
Erectile difficulties
Reduced spontaneous erections
Reduced sexual wellbeing
It is important to remember that sexual difficulties can have many causes, so they should be discussed with your GP or healthcare team rather than automatically being attributed to low testosterone.
Other effects
Testosterone deficiency can also contribute to:
Persistent tiredness or reduced energy
Reduced muscle mass and strength
Reduced body or facial hair
Low mood or changes in emotional wellbeing
Difficulty concentrating
Reduced bone density and an increased risk of osteoporosis
Anaemia in some people
Breast enlargement or tenderness in some men
The symptoms and severity vary from person to person.
How is pituitary-related hypogonadism diagnosed?
Your healthcare team will consider your symptoms, medical history and pituitary diagnosis.
Tests may include:
Blood tests
Blood tests can measure hormone levels, including:
Testosterone
LH
FSH
Prolactin
Other pituitary hormones where appropriate
Testosterone is generally assessed using an appropriate morning blood sample, and a low result may need to be confirmed with repeat testing.
Semen analysis
If fertility is a concern, a semen analysis can assess sperm concentration, movement and other characteristics.
Further investigations may be recommended depending on the results.
Other investigations
Depending on your individual circumstances, your endocrinologist or fertility specialist may recommend additional tests or imaging.
Can fertility be restored?
In many men with pituitary-related hypogonadism, fertility may be improved with appropriate hormone treatment.
However, treatment is highly individual and should be managed by an endocrinologist and, where appropriate, a fertility specialist or andrology team.
Treatment may involve replacing the hormones that the pituitary is unable to produce adequately.
Gonadotrophin treatment
For men whose infertility is caused by a lack of LH and FSH, treatment with gonadotrophins may stimulate testosterone production and sperm production.
Treatment can involve:
hCG (human chorionic gonadotrophin) to provide LH-like stimulation
FSH preparations to stimulate sperm production
In some circumstances, other approaches such as pulsatile GnRH treatment may be considered.
Treatment can take time. Sperm production may take several months or longer to improve, and regular semen analyses may be required to assess the response.
The HSE notes that hormonal treatment may improve sperm production when a hormonal imbalance is contributing to male fertility problems.
An important difference: testosterone treatment and fertility treatment
If you are hoping to have children, tell your endocrinologist before starting testosterone replacement therapy.
Testosterone replacement can improve symptoms caused by low testosterone, but testosterone treatment does not stimulate sperm production.
In fact, taking testosterone from outside the body can reduce the pituitary signals needed to stimulate the testes and can therefore reduce sperm production.
For men who wish to preserve or achieve fertility, treatment may instead involve gonadotrophins or another fertility-focused approach, depending on the underlying cause.
The Endocrine Society recommends against starting testosterone therapy in men who are planning fertility in the near term.
If fertility is important to you, discuss your plans with your endocrinologist before starting or changing testosterone treatment.
Testosterone replacement therapy
If fertility is not currently a goal, testosterone replacement may be recommended for men with confirmed central hypogonadism and symptoms or other consequences of testosterone deficiency, provided there are no contraindications.
Treatment aims to restore testosterone to an appropriate physiological level.
Depending on what is available and appropriate for you, testosterone may be prescribed in different forms, such as:
Gels applied to the skin
Injections
Other formulations prescribed by your healthcare team
Your endocrinologist will discuss the most appropriate treatment for you.
The aim is hormone replacement, not to produce testosterone levels above the normal range.
What benefits might testosterone replacement provide?
Where testosterone deficiency has been confirmed, appropriate replacement may improve some symptoms associated with low testosterone.
Potential benefits can include:
Improved libido
Improved sexual function
Increased energy
Improved sense of wellbeing
Improved muscle mass and strength
Support for bone health
Improvement in some symptoms associated with testosterone deficiency
Not everyone experiences the same benefits, and improvement can take time.
Testosterone treatment should be reviewed regularly by your healthcare team.
What are the possible side effects?
As with any medical treatment, testosterone replacement can have side effects.
Depending on the treatment used, these may include:
Skin irritation with gels
Acne
Fluid retention
Changes in red blood cell levels
Changes in prostate-related symptoms
Reduced sperm production
Other effects depending on the formulation and individual circumstances
Your healthcare team will discuss the potential benefits and risks with you and decide what monitoring is appropriate.
Do not change your dose or stop treatment without discussing this with your healthcare professional.
How long will treatment be needed?
The duration of treatment depends on the underlying cause.
If the pituitary gland is permanently damaged and testosterone production remains deficient, long-term testosterone replacement may be required.
If fertility treatment with gonadotrophins is being used, treatment is generally focused on achieving sperm production and fertility and may therefore be different from long-term testosterone replacement.
Your endocrinologist will discuss your individual treatment plan with you.
Monitoring during testosterone treatment
If you are prescribed testosterone replacement, you will need appropriate follow-up.
Your healthcare team may monitor:
Testosterone levels
Symptoms and response to treatment
Full blood count/haematocrit
Blood pressure and other relevant health measures
Prostate health where appropriate
Other tests depending on your age, medical history and treatment
The exact monitoring schedule should be determined by your doctor based on your individual circumstances.
Current guidance emphasises confirming the diagnosis, assessing response and monitoring for potential adverse effects rather than using a single routine monitoring schedule for every man.
What if I want to have children in the future?
If you think you may want children in the future, tell your endocrinologist.
This is particularly important if you are considering testosterone replacement.
Your healthcare team may discuss fertility preservation or treatment options depending on your circumstances.
In some situations, sperm may be stored for future use following discussion with a fertility specialist.
If fertility is an important consideration, it may be appropriate to seek specialist advice before starting testosterone treatment.
Fertility support in Ireland
If you are concerned about fertility, speak with your GP, endocrinologist or fertility specialist.
Depending on your circumstances, you may be referred for specialist fertility assessment.
Assessment and treatment can involve endocrinology, fertility medicine, reproductive medicine and/or andrology.
The HSE provides information about fertility investigations and treatment, including assessment of male fertility and hormonal causes of infertility.
Because fertility services and eligibility criteria can change, we recommend checking the current information directly with the HSE and the healthcare service providing your care.
Does having a pituitary tumour mean it is hereditary?
Most pituitary tumours occur sporadically and are not inherited.
However, a small number of pituitary tumours occur as part of inherited genetic conditions.
If you have been diagnosed at a young age, have several family members with pituitary or endocrine conditions, or your doctor suspects a genetic syndrome, you may be referred for appropriate specialist or genetic assessment.
Your fertility and your wellbeing matter
Fertility difficulties and changes in sexual function can have a significant emotional impact.
It is completely understandable to experience worry, frustration, embarrassment or uncertainty.
You do not have to deal with these concerns alone.
Talking openly with your GP, endocrinologist, fertility specialist or another healthcare professional can help you understand your options.
Your partner may also benefit from being involved in discussions where appropriate.
When should I speak to my
healthcare team?
Speak with your GP or endocrinology team if you experience:
Reduced libido
Erectile difficulties
Persistent fatigue or low energy
Reduced muscle strength
Changes in body or facial hair
Concerns about low testosterone
Difficulty conceiving
Concerns about your fertility
Questions about testosterone replacement
Plans to have children while taking testosterone
Do not start, stop or change testosterone or other hormone treatment without medical advice.
Important information for people living in Ireland
Information about pituitary conditions and fertility can vary between countries because healthcare systems, fertility services, medication availability and treatment pathways are different.
This page has therefore been adapted for people living in the Republic of Ireland.
Pituitary Ireland does not operate or maintain a national pituitary patient registry, and there is currently no national pituitary patient registry in the Republic of Ireland comparable to some registry systems referenced in information from other countries.
Information from organisations outside Ireland, including the Pituitary Foundation UK, may therefore not always reflect the healthcare services, referral pathways, eligibility criteria or treatment availability in Ireland.
For information about your individual treatment or fertility options, please speak with your GP, endocrinologist, fertility specialist or other appropriate healthcare professional.
A note from Pituitary Ireland
Pituitary Ireland provides information, education, support and community for people affected by pituitary conditions in the Republic of Ireland.
We do not provide individual medical or fertility advice, diagnose conditions or recommend specific treatments.
If you have concerns about your hormones, sexual health or fertility, please speak with your healthcare team.
Your pituitary condition should not define your hopes for the future — and if having children is important to you, specialist help may be available.
The Pituitary Foundation UK
Male Hormones & Fertility
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