Delayed puberty (no breasts at 13 years, no testicular enlargement at 14 years) and primary amenorrhoea

Laboratory tests in the morning (before 10 am)

• LH
• FSH
• Total testosterone (boy), in the morningif needednon-French guidelineIn boys: baseline testosterone is part of the initial screening; it follows a circadian rhythm and is measured in the morning ^[1].
• Oestradiol (girl)if needednon-French guidelineIn girls: a low oestradiol may suggest hypogonadism; a level > 50 pg/mL has been proposed to rule it out; sleep, diet, acute illness and assay technique alter the values, so no single threshold is validated ^[1].
• FBC
• CRP
• Serum creatinine with eGFR
• TSH
• Free T4 (state "looking for pituitary deficiency")
• IgA anti-tissue transglutaminase antibodies (tTG-IgA)if neededCoeliac disease screening is part of the initial tests proposed in the 2024 review ^[1]; NICE recommends it for slowing growth, digestive disorders, prolonged fatigue or weight loss ^[2], and the NABM reimburses it first-line when coeliac disease is suspected ^[3].
• Total IgAif neededCoeliac disease screening is part of the initial tests proposed in the 2024 review ^[1]; NICE recommends it for slowing growth, digestive disorders, prolonged fatigue or weight loss ^[2], and the NABM reimburses it first-line when coeliac disease is suspected ^[3].
• IGF-1 (if slowing of height growth)if needednon-French guidelineIGF-1 and prolactin are used to look for another pituitary deficiency ^[1]; a marked slowing of growth suggests growth hormone deficiency ^[1].
• Serum prolactin (if headache, visual disturbance, galactorrhoea, other pituitary sign)if needednon-French guidelineProlactin is among the assays proposed to rule out another pituitary deficiency, hyperprolactinaemia being a cause of functional delayed puberty ^[1].
• Serum electrolytesif needednon-French guidelineRenal and liver function and electrolytes are among the tests advised to rule out an underlying chronic disease ^[1].
• ASTif needednon-French guidelineRenal and liver function and electrolytes are among the tests advised to rule out an underlying chronic disease ^[1].
• ALTif needednon-French guidelineRenal and liver function and electrolytes are among the tests advised to rule out an underlying chronic disease ^[1].
• Blood karyotype (in a short girl or one with signs of Turner syndrome; signed consent form enclosed)if neededIn girls, the 2024 international Turner syndrome guideline asks for chromosome analysis for unexplained short stature, unexplained delayed puberty or suggestive signs, each sufficient on its own, counting at least 30 metaphases (expert consensus) ^[4]; the French PNDS also raises the syndrome in the adolescent girl with a height deficit ≤ -2 SD or no breast development after age 13 ^[5]. Without these signs, the karyotype is discussed after LH and FSH measurement (“High gonadotrophins” tab).

Imaging

• PA X-ray of the left hand and wrist (bone age).

Laboratory tests

• Serum β-hCG
• FSH
• Oestradiol
• TSH
• Serum prolactin

Imaging

• Pelvic ultrasound (presence of the uterus) if gynaecological examination is not feasible.

Laboratory tests

• LH
• FSH
• Blood karyotype (enclose the information and consent form signed by the holders of parental authority)

• No other laboratory tests in the community: opinion of a paediatric endocrinologist if any feature is atypical for simple delay or if puberty does not start during follow-up.