Female Hormones and Fertility
How can a pituitary condition affect female
hormones and fertility?
The pituitary gland plays an important role in regulating the menstrual cycle, ovulation, female sex hormones and fertility.
Two pituitary hormones — luteinising hormone (LH) and follicle-stimulating hormone (FSH) — are particularly important.
They work together with hormones produced by the hypothalamus and ovaries to regulate the menstrual cycle and ovulation.
If the pituitary gland does not produce enough LH and FSH, the ovaries may not receive the hormonal stimulation they need to develop and release an egg. This can lead to irregular or absent periods, low oestrogen levels and difficulty becoming pregnant.
This type of hormone deficiency is sometimes called central or secondary hypogonadism.
The effects vary from person to person and depend on the underlying pituitary condition and which hormones are affected.
What are the main female reproductive hormones?
Follicle-stimulating hormone (FSH)
FSH stimulates the development of ovarian follicles, which contain developing eggs.
During the menstrual cycle, FSH helps an ovarian follicle develop and supports the production of oestrogen.
Luteinising hormone (LH)
LH plays an important role in ovulation.
A surge in LH normally triggers the release of a mature egg from the ovary.
LH also helps the ovary produce hormones after ovulation.
Oestrogen
Oestrogen is produced mainly by the ovaries before menopause.
It is important for:
Development of female reproductive characteristics
Regulation of the menstrual cycle
Maintaining the health of the vagina and reproductive tissues
Maintaining bone health
Supporting cardiovascular and metabolic health
Sexual wellbeing and libido
General wellbeing
Progesterone
Progesterone is produced mainly after ovulation.
It helps prepare the lining of the womb for a possible pregnancy and supports the early stages of pregnancy.
How does the pituitary control the menstrual cycle?
The process begins in the hypothalamus, which releases gonadotrophin-releasing hormone (GnRH).
GnRH stimulates the pituitary gland to release LH and FSH.
LH and FSH then act on the ovaries.
This communication between the hypothalamus, pituitary gland and ovaries is sometimes referred to as the hypothalamic-pituitary-ovarian (HPO) axis.
If the pituitary gland is damaged or is not functioning properly, it may not produce enough LH and FSH.
As a result:
Reduced LH and FSH → reduced ovarian stimulation → reduced oestrogen production and/or failure to ovulate → irregular or absent periods and possible infertility.
What is hypogonadism?
Hypogonadism occurs when the ovaries are not producing sufficient sex hormones or the hormonal signals needed for normal reproductive function are not working properly.
When the problem originates in the pituitary gland or hypothalamus, it may be called central or secondary hypogonadism.
In women with a pituitary condition, this can result in:
Low oestrogen levels
Irregular periods
Absent periods
Lack of ovulation
Vaginal dryness
Reduced libido
Difficulty becoming pregnant
Reduced bone density over time
The Endocrine Society recommends assessment of oestradiol, LH and FSH when central hypogonadism is suspected in women with absent or infrequent periods, while other causes such as pregnancy, thyroid disease and high prolactin should also be considered.
What can cause pituitary-related hormone deficiency?
A number of conditions can affect the pituitary gland and 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 injury or damage affecting the pituitary or hypothalamus
Sheehan's Syndrome
Certain congenital or genetic conditions
Other conditions affecting the pituitary or hypothalamus
Most pituitary adenomas are benign (non-cancerous), although they can affect normal pituitary hormone production.
Treatment for a pituitary tumour, including surgery or radiotherapy, can also sometimes affect hormone production.
What are the effects of low female hormones?
The symptoms can vary considerably depending on which hormones are affected and how severe the deficiency is.
Menstrual changes
Low LH and FSH stimulation can cause:
Irregular periods
Infrequent periods
Very light periods
Absent periods (amenorrhoea)
Difficulty predicting when a period will occur
If ovulation does not occur regularly, becoming pregnant may be more difficult.
The HSE identifies ovulation problems, including irregular or absent periods, as an important cause of fertility problems in women.
Fertility
If LH and FSH are insufficient, ovulation may not occur normally.
Without regular ovulation, there may be fewer opportunities for an egg to be fertilised.
Pituitary-related hormone deficiency can therefore contribute to infertility or subfertility.
However, having a pituitary condition does not necessarily mean that pregnancy is impossible.
Depending on the underlying cause, fertility treatment may be able to stimulate ovulation.
Other symptoms of low oestrogen
Low oestrogen can cause symptoms such as:
Hot flushes
Night sweats
Vaginal dryness
Pain or discomfort during sex
Reduced libido
Changes in mood
Tiredness
Difficulty sleeping
Reduced bone density
Increased risk of osteoporosis over time
Not everyone experiences all of these symptoms.
Why is oestrogen important for bone health?
Oestrogen plays an important role in maintaining healthy bones.
Long-term oestrogen deficiency can contribute to reduced bone density and osteoporosis, particularly when hormone deficiency occurs before the usual age of menopause.
For women with pituitary-related hypogonadism, appropriate hormone replacement may therefore be important not only for menstrual and reproductive health but also for longer-term health.
Your endocrinologist will assess your individual hormone replacement needs and may recommend monitoring of bone health where appropriate.
How is pituitary-related hormone deficiency diagnosed?
Your GP or endocrinologist will consider your symptoms, medical history, menstrual history and existing pituitary diagnosis.
Blood tests may include:
Oestradiol
LH
FSH
Prolactin
Thyroid hormones
Other pituitary hormones where appropriate
If periods have stopped, pregnancy should also be excluded where relevant.
The Endocrine Society recommends measuring oestradiol, FSH and LH in women with oligomenorrhoea or amenorrhoea when central hypogonadism is suspected, while considering other possible causes.
Depending on your circumstances, additional investigations may be required.
What if I want to have children?
If you have a pituitary condition and would like to become pregnant, talk to your endocrinologist and GP.
It is particularly important to discuss your plans before trying to conceive because some pituitary hormone deficiencies and medications require careful management before and during pregnancy.
Your healthcare team can assess:
Whether you are ovulating
Your hormone levels
Your pituitary function
Other factors that may affect fertility
Whether fertility treatment may be appropriate
The HSE advises women with a health condition that may affect fertility to seek medical advice rather than waiting before discussing fertility concerns.
Can fertility be restored?
In some women with pituitary-related hormone deficiency, ovulation can be stimulated with fertility treatment.
Treatment is highly individual and should be managed by an endocrinologist and fertility specialist.
Depending on the underlying cause, treatment may involve hormone therapy designed to stimulate the ovaries and induce ovulation.
Gonadotrophin treatment
Gonadotrophin treatment can provide the hormonal stimulation that the pituitary gland is unable to provide.
This may involve preparations containing:
FSH
LH activity
Other gonadotrophin medications
Treatment is carefully monitored because the ovaries need to be stimulated appropriately and there can be a risk of developing too many follicles.
Ultrasound and blood tests may be used to monitor treatment.
The aim is to achieve appropriate follicular development and ovulation while minimising risks.
Fertility treatment in Ireland
If you are having difficulty becoming pregnant, your GP or consultant can advise you about fertility assessment and referral.
The HSE provides fertility testing and treatment through regional fertility hubs for people who meet the relevant criteria. These services include assessment of hormonal causes of fertility problems and treatment for women who are not ovulating.
The HSE currently lists regional fertility hub services in:
Cork
Dublin
Galway
Tipperary
Eligibility criteria apply and can change, so always check the latest HSE information or speak with your GP or consultant.
The HSE also provides specialist fertility treatments, including IVF, ICSI and IUI, for people who meet the relevant criteria. Private fertility treatment may also be available.
Oestrogen replacement therapy
If your pituitary gland is not producing enough LH and FSH and you have low oestrogen as a result, your endocrinologist may recommend female sex hormone replacement.
For women who have not reached natural menopause, hormone replacement may help replace the oestrogen that the ovaries are no longer producing adequately.
Treatment may be given in different forms, including:
Tablets
Skin patches
Gels
Other preparations depending on your individual circumstances
The most appropriate treatment depends on your age, symptoms, medical history, other hormone deficiencies and whether pregnancy is a current or future goal.
The Endocrine Society recommends gonadal hormone treatment for premenopausal women with central hypogonadism when there are no contraindications.
Oestrogen replacement and fertility are not the same treatment
It is important to understand that oestrogen replacement therapy is not the same as fertility treatment.
Oestrogen replacement can help replace missing hormones and may help protect bone and other aspects of health.
However, it does not necessarily restore ovulation or allow pregnancy to occur.
If you wish to become pregnant, you may need a different fertility-focused treatment plan designed to stimulate ovulation.
Always tell your endocrinologist if you are considering pregnancy.
What about progesterone?
If you have a womb and are receiving oestrogen replacement, your healthcare team will consider whether progesterone or another progestogen is also required.
This is important because, in women with an intact womb, taking oestrogen without appropriate progestogen protection can increase the risk of changes to the lining of the womb.
Your endocrinologist or other healthcare professional will advise you on the appropriate combination and treatment schedule.
What are the benefits of hormone replacement?
When appropriate, hormone replacement can help manage symptoms and reduce some of the longer-term effects of hormone deficiency.
Potential benefits may include:
More predictable or restored menstrual bleeding
Reduction in hot flushes and night sweats
Improvement in vaginal symptoms
Improved sexual wellbeing
Support for bone health
Protection against some consequences of prolonged oestrogen deficiency
Improved overall wellbeing in some women
Your healthcare team will review the benefits and risks for you individually.
What are the possible side effects?
Hormone replacement can cause side effects, although not everyone experiences them.
Depending on the treatment, these may include:
Breast tenderness
Bloating
Headaches
Nausea
Changes in mood
Vaginal bleeding or spotting
Skin irritation where patches or gels are used
Your doctor will discuss the potential benefits and risks with you.
Do not stop or change hormone replacement without discussing it with your healthcare team.
How long will treatment be needed?
The duration of hormone replacement depends on the cause of the hormone deficiency and your individual circumstances.
If the pituitary gland has been permanently damaged and the ovaries are not receiving adequate hormonal stimulation, long-term hormone replacement may be recommended, particularly before the usual age of menopause.
Your hormone requirements may change over time.
Your endocrinologist will review your treatment and make adjustments when necessary.
What happens if I become pregnant?
Pregnancy can require changes to the management of pituitary hormone deficiencies.
If you are planning pregnancy, speak with your endocrinologist before trying to conceive, where possible.
This allows your healthcare team to review your medication and hormone replacement and make sure your pituitary conditions are appropriately managed.
Once pregnant, you may need closer monitoring by your endocrinology and maternity teams.
Some pituitary hormone deficiencies, particularly adrenal insufficiency and central hypothyroidism, require specific management during pregnancy.
Do not stop hormone replacement medication because you are pregnant unless your healthcare team specifically advises you to do so.
Pregnancy after pituitary surgery or treatment
If you have previously had:
Pituitary surgery
Radiotherapy
A pituitary tumour
Sheehan's Syndrome
Hypopituitarism
Another condition affecting pituitary function
it is particularly important to tell your GP, endocrinologist and maternity team if you are planning a pregnancy.
Your healthcare team can assess your current pituitary function and determine whether any treatment needs to be adjusted.
Fertility does not always depend on pituitary hormones alone
A pituitary condition may contribute to fertility difficulties, but it is not necessarily the only factor involved.
Other factors can affect fertility, including:
Age
Ovarian reserve
Endometriosis
Polycystic ovary syndrome (PCOS)
Problems affecting the fallopian tubes
Uterine conditions
Previous pelvic surgery or infection
Sperm-related fertility factors in a partner
Other medical conditions
The HSE recommends appropriate fertility assessment because there can be multiple causes of fertility difficulties.
When should I speak to my GP or endocrinologist?
Speak with your healthcare team if you experience:
Irregular or absent periods
Hot flushes or night sweats
Vaginal dryness
Reduced libido
Difficulty becoming pregnant
Symptoms that may suggest low oestrogen
Concerns about your bone health
Questions about hormone replacement
Plans to become pregnant
Changes in your pituitary condition or treatment
The HSE advises seeking medical advice sooner if you have a health condition known to affect fertility rather than necessarily waiting for the usual period of trying to conceive.
Looking after your fertility and long-term health
If you are living with a pituitary condition, managing your hormone deficiencies appropriately can be an important part of protecting your long-term health.
Regular follow-up with your endocrinology team can help monitor:
Pituitary hormone function
Oestrogen replacement
Menstrual health
Bone health
Other hormone deficiencies
Symptoms and overall wellbeing
If you are considering pregnancy, make sure your healthcare team knows about your plans.
Information for people living in Ireland
Fertility services, referral pathways, treatment availability and eligibility criteria can vary between countries.
Information published by organisations outside Ireland, including the Pituitary Foundation UK, may therefore not always reflect the healthcare system or fertility services available 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 referred to in information from other countries.
For information about your individual fertility, hormone replacement or pregnancy plans, please speak with your GP, endocrinologist, fertility specialist or maternity healthcare team.
Pituitary Ireland
At Pituitary Ireland, we understand that living with a pituitary condition can affect many aspects of life, including reproductive health, relationships, family planning and future hopes.
We provide 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, menstrual cycle, fertility or plans for pregnancy, please speak with your healthcare team.
Your pituitary condition does not necessarily mean that pregnancy is impossible. If having children is important to you, speak with your healthcare team about your options.