For diagnosing premature ovarian insufficiency (POI) in individuals under 40, consider their clinical and family history NICE NG23. The diagnosis is based on menopause-associated symptoms, such as absent or infrequent periods (accounting for hysterectomy), alongside elevated follicle-stimulating hormone (FSH) levels confirmed on two blood samples taken 4 to 6 weeks apart NICE NG23. A single blood test is insufficient for diagnosis NICE NG23. Anti-Müllerian hormone testing is not routinely used for diagnosing POI NICE NG23.
For women with irregular menstrual cycles, serum gonadotrophin measurements (follicle-stimulating hormone and luteinising hormone) are valuable for identifying ovulation disorders NICE CG156,NICE CKS. Serum progesterone measurement in the mid-luteal phase can confirm ovulation, even in women with regular cycles NICE CG156. For those with prolonged irregular cycles, serum progesterone may need to be measured later in the cycle and repeated weekly until the next menstrual period begins NICE CG156,NICE CKS.
Thyroid function tests should only be offered to women with symptoms of thyroid disease NICE CG156,NICE CKS. Prolactin measurement is indicated for women with ovulatory disorders, galactorrhoea, or a suspected pituitary tumour NICE CG156,NICE CKS.