The hypothalmus produces GnRH which stimulates the synthesis and release of FSH & LH in the ovaries, which then provokes ovarian follicle maturation and together with LH, encourages oestrogen secretion and ovulation. FSH is subject to oestrogen feed-back from the gonads via the hypothalamic pituitary gonadal axis. It peaks at day 3 in women. In men, FSH stimulates the Sertoli cells to undergo spermatogenesis and induce sperm production. FSH levels are also useful in the investigation of menstrual irregularities and to aid in the diagnosis of pituitary gland disorders.
Follicle Stimulating Hormone (FSH)
Follicle Stimulating Hormone (FSH)
Follicle stimulating hormone (FSH) is a gonadotrophin released by the anterior pituitary in response to pulsatile gonadotrophin releasing hormone stimulation. It has an important role in sexual development and functioning.
In women, measurement of serum FSH is useful in patients to investigate irregular periods, to evaluate for menopause onset in certain age groups, as part of initial fertility workup testing, to evaluate for delayed or precocious puberty and to assess pituitary disorders.
High FSH concentration in the initial phases of the menstrual cycle, the follicular phase, is an early indicator of poor ovarian response for ovulation later on in that cycle. In menopause, two FSH levels >30, taken 6 weeks apart, can be an indicator of menopause. POI, or premature ovarian failure can occur post oophorectomy, post radiation or chemotherapy, or due to autoimmune conditions. It can also occur due to congenital absence or agenesis of the ovaries or in those with underlying genetic causes such as Turners syndrome, fragile X syndrome. In young children, high levels of FSH and LH and development of secondary sexual characteristics at an unusually young age are an indication of precocious (early) puberty.
Low levels of FSH are seen most commonly seen in conjunction with low LH and low GnRH and indicate a disruption of the hypothalamic pituitary ovarian axis – hypogonadotrophic hypopituitarism. This is a reversible condition often caused by excessive weight loss, exercise or stress. Low FSH also occurs in women on the oral combined contraceptive pill or those with PCOS.
In men, FSH levels are found to be decreased in men with hypopituitarism, adrenal tumours and those taking testosterone medication. FSH is found to be increased if there is primary testicular failure as a result of gonadal agenesis or underlying genetic disorder which affects sexual development such as Klinefelters syndrome. Secondary testicular failure can occur after mumps infection, after traumatic injury, post chemotherapy or radiotherapy, from chronic alcohol abuse or if there is an underlying genetic disorder which affects sexual development such as Klinefelters syndrome.
5mL venous serum
In addition to the packaging of samples, the transport/delivery of clinical samples to the laboratory is required to be in adherence to all national regulations for the safe transport of biological materials. Enfer Medical provides a fully compliant logistics service, aligned with clients’ testing requirements.
Prompt transport of specimens:
To ensure prompt testing of samples and release of results within the published test turnaround times, samples should arrive to the laboratory by 18:00. Test turnaround time is measured from receipt of the sample at the laboratory until the time the authorised results are reported to users.
In rare cases specimens may not be suitable for testing on arrival to the laboratory. In that case the sample will be rejected at the receipt stage and the service user will be notified immediately and an explanation as to why the sample could not be processed will be provided. Reasons why samples cannot be processed include but are not limited to:
- Samples received beyond the stability limits and/or not at the correct temperature indicated for each test.
- Incorrect sample type received.
- Leaking samples, sample not received or sample insufficient for analysis as stated below within sample requirements.
- Non-compliant samples or request forms i.e. those missing sample date information, missing sample test request and/or missing sample site/type information.
- Samples received without the necessary patient identifiers.
Quantitative results for Follicle Stimulating Hormone (FSH) are reported in numeric value in mIU/mL. Please contact us for more information on the reference ranges used at Enfer Medical.