Secondary amenorrhoea

Fasting laboratory tests between 7 am and 11 am

• FSH
• LH
• TSH
• Free T4 (if FSH, LH and oestradiol low or pituitary involvement suspected)if needednon-French guidelineTSH is the first-line thyroid test for any menstrual disorder, but it is hard to interpret in hypothyroidism of pituitary origin (for example Sheehan's syndrome): ASRM (2024) then asks to add free T4 ^[1]. First-line, ASRM retains TSH alone, free T4 being added if TSH is abnormal or in case of pituitary involvement ^[1].
• Prolactin
• Oestradiol
• Serum testosterone (if signs of hyperandrogenism or PCOS suspected)if needednon-French guidelineTo request when amenorrhoea comes with signs of hyperandrogenism (hirsutism, acne, alopecia) or when the picture suggests PCOS: total testosterone helps to document hyperandrogenism and look for its origin ^[1,2].
• SHBG (if signs of hyperandrogenism or PCOS suspected, with testosterone)if needednon-French guidelineTo combine with testosterone when looking for biochemical hyperandrogenism: the international PCOS guideline (2023, endorsed in Australia by the NHMRC) assesses it by total and free testosterone, free testosterone being estimable by the free androgen index, calculated from SHBG ^[2]; a Scottish primary care pathway (NHS Borders, 2025) asks for SHBG and free androgen index straight away ^[3]. The French Society of Endocrinology (2010) recommends total testosterone first-line and cites SHBG only to interpret a discordant result (low in overweight or metabolic syndrome, high on oestrogen-like treatment, in hyperthyroidism or liver disease) ^[4].
• hCGif needednon-French guidelineAs long as pregnancy has not been formally excluded: it is the first diagnosis to exclude before hormone tests. A urine test can be falsely negative; a blood test may be preferred ^[1].

Laboratory tests

• Synacthen test with 17-hydroxyprogesterone

24-hour urine collection

• Urinary free cortisol
• DHEA-S (if testosterone > 2 times normal)if neededTotal testosterone above twice the upper limit: DHEA-S points to an adrenal origin (very high level) or ovarian origin (normal level) ^[4]. NABM coverage limited to adrenal diseases (code 1802): justified here if an adrenal tumour or hyperplasia is suspected ^[6].

Laboratory tests

• FSH (repeat at 4-6 weeks)if needednon-French guidelineDiagnostic doubt (initial value poorly consistent with the clinical picture): ESHRE asks to repeat FSH after 4 to 6 weeks; a single measurement is enough if the picture is typical ^[5].
• Blood karyotype (attach the information and consent certificate)
• FMR1 premutation testing (fragile X)if needednon-French guidelineRecommended by ESHRE in every woman with non-iatrogenic ovarian insufficiency, after information on the implications of the test ^[5]; see the page "Genetic tests: prescribing framework".
• Anti-21-hydroxylase antibodiesif neededOvarian insufficiency of unknown cause: ESHRE recommends looking for them (if positive: endocrinology opinion to investigate adrenal function) ^[5]. Only code 1489 (anti-adrenal antibodies by immunofluorescence) exists in the NABM: check with the laboratory ^[6].