Human Development

Delayed puberty: workup

Clinical Overview and When to Suspect Delayed Puberty

— Boys: No testicular enlargement (testes <4 mL or <2.5 cm long axis) by age 14

— Girls: No breast budding (Tanner 2) by age 13, or no menarche by age 15 (or >5 years after thelarche = primary amenorrhea workup overlap)

— Constitutional delay of growth and puberty (CDGP): most common cause, especially in boys; positive family history of "late bloomer" parent in ~75%

— Functional hypogonadotropic hypogonadism: chronic illness, malnutrition, eating disorders, intense athletics, hypothyroidism, IBD, celiac, CF

— Pathologic hypogonadism: permanent central (Kallmann, pituitary lesion, cranial radiation) or primary gonadal (Turner, Klinefelter, gonadal damage)

— Anosmia/hyposmia → Kallmann syndrome

— Short stature in a girl with delayed puberty → Turner syndrome until proven otherwise

— Tall stature, small firm testes in a boy → Klinefelter (47,XXY)

— Headaches, visual field cuts, polyuria → CNS/pituitary mass

— Midline defects (cleft lip/palate, single central incisor) → hypopituitarism

Definition (US norms): Absence of secondary sexual characteristics by ages that fall >2–2.5 SD beyond population mean

Epidemiology: ~2% of adolescents; boys present far more often than girls (boys self-identify due to short stature/locker-room comparison; girls with delay more often have pathology)

Three buckets to keep in mind from the first encounter:

When to suspect pathology over CDGP early:

Board pearl: A boy whose bone age lags chronologic age but matches height age, with a family history of late puberty, is the classic CDGP stem — workup is reassuring, not extensive. Conversely, bone age = chronologic age in a non-pubertal teen makes CDGP unlikely and pushes you toward pathology.

Step 3 management: Initial visit centers on confirming pubertal stage (Tanner), plotting growth velocity, and ordering a bone age film before chasing exotic labs.

Presentation Patterns and Key History

— Boy: "shorter than classmates," "voice hasn't changed," teasing, sports performance

— Girl: "no period," "no breast development," parents noting lag behind sisters

— Was growth velocity normal until recently? Plateau in mid-childhood → acquired pituitary/hypothalamic lesion or hypothyroidism

— Lifelong short stature with steady percentile → Turner, GH deficiency, skeletal dysplasia

— Normal height with isolated pubertal delay → think isolated hypogonadotropic hypogonadism (IHH/Kallmann)

— Mother's age at menarche, father's age at shaving/growth spurt

— Family members requiring fertility treatment → congenital HH

— Consanguinity → autosomal recessive forms

— Calorie intake, restrictive eating, vegan without supplementation

— Athletic hours/week (>10 hrs endurance training suppresses GnRH)

— Weight loss or failure to gain

— Anosmia (can't smell coffee, perfume) → Kallmann

— Headache, vomiting, vision change, polyuria/polydipsia → suprasellar mass, craniopharyngioma

— GI symptoms, mouth ulcers, diarrhea → celiac, IBD

— Cold intolerance, constipation, fatigue → hypothyroidism

— Galactorrhea → prolactinoma

— Cranial radiation, chemotherapy (alkylators damage gonads)

— Cryptorchidism, orchiopexy, testicular torsion

— Autoimmune disease (polyglandular syndromes)

Chief complaint clues:

Growth trajectory questions (high yield):

Family history (essential for CDGP diagnosis):

Nutrition and energy availability:

Systems review red flags:

Past medical/surgical:

Medications/exposures: Glucocorticoids, opioids (suppress GnRH), antipsychotics (hyperprolactinemia), cannabis

Key distinction: CDGP vs congenital hypogonadotropic hypogonadism can look identical at age 14 — both have low LH/FSH and low sex steroids. The differentiators are family history, anosmia, micropenis or cryptorchidism in infancy (suggests congenital HH), and ultimately spontaneous progression with time. This distinction is the central diagnostic challenge of the topic and a favorite of question writers.

Physical Exam Findings

— Plot height, weight, BMI on CDC curves; calculate mid-parental height ([father + mother ± 13 cm]/2)

— Calculate growth velocity (cm/yr): prepubertal normal ~5 cm/yr; <4 cm/yr is abnormal

— Arm span vs height: eunuchoid habitus (span > height by >5 cm, lower segment > upper) suggests delayed epiphyseal closure from hypogonadism (Klinefelter, untreated HH)

— Boys: testicular volume by orchidometer is the earliest sign of puberty; ≥4 mL = puberty onset

— Girls: breast bud (palpate, don't just inspect — fat pad fools you), pubic hair distribution

— Pubic/axillary hair alone = adrenarche, not gonadarche; can be normal without true puberty

— Turner syndrome: short stature, webbed neck, shield chest, widely spaced nipples, cubitus valgus, low hairline, lymphedema of hands/feet, low-set ears, high-arched palate, fourth metacarpal shortening

— Klinefelter: tall stature, small firm testes (<6 mL despite virilization), gynecomastia, eunuchoid proportions, learning issues

— Kallmann: anosmia (formally test with alcohol pad/coffee), midline defects, synkinesia (mirror movements), unilateral renal agenesis

— Prader-Willi: hypotonia history, hyperphagia, almond eyes, small hands/feet

— Hypothyroidism: dry skin, delayed reflex relaxation, goiter, bradycardia

— Cushing/exogenous steroids: central obesity, striae, moon facies with growth arrest

Anthropometrics first — always:

Tanner staging (must document):

Targeted findings by etiology:

Neurologic exam: visual fields by confrontation (bitemporal hemianopsia → sellar mass), funduscopy for papilledema, cranial nerves

Skin: café-au-lait (McCune-Albright is precocious not delayed, but neurofibromatosis can cause optic glioma → central HH)

Board pearl: Testicular volume ≥4 mL = puberty has started, even if the boy looks prepubertal otherwise — measure with a Prader orchidometer, not by eyeball. A boy at age 14 with 4 mL testes has CDGP, not pathology, and reassurance is appropriate.

Diagnostic Workup — Initial Labs and Bone Age

— Bone age delayed relative to chronologic age (typically by ≥2 years) → consistent with CDGP or any cause that delays epiphyseal maturation

— Bone age equal to chronologic age in a non-pubertal teen → CDGP unlikely; pursue pathology aggressively

— Predicts remaining growth potential and final adult height

— LH, FSH (basal, morning) — distinguishes central vs primary

— Estradiol (girls) or total testosterone (boys, 8 AM) — confirms hypogonadism

— TSH, free T4 — hypothyroidism is a fixable mimic

— Prolactin — elevated suggests prolactinoma or stalk effect

— CBC, CMP, ESR/CRP — screen for occult chronic disease (IBD, renal)

— Tissue transglutaminase IgA + total IgA — celiac is a classic occult cause

— IGF-1, IGFBP-3 — screens for GH deficiency

— Low LH/FSH + low sex steroid = hypogonadotropic (central): CDGP, functional, or congenital HH/Kallmann, pituitary disease

— High LH/FSH + low sex steroid = hypergonadotropic (primary gonadal failure): Turner, Klinefelter, gonadal damage

— Normal LH/FSH + normal sex steroid in a Tanner 1 teen = early puberty just hasn't shown yet; reassess in 6 months

Bone age radiograph (left hand/wrist, Greulich-Pyle): the single most useful first test

First-line laboratory panel (order all at first visit):

Interpretation framework:

Pelvic/abdominal ultrasound in girls: uterine and ovarian assessment; streak ovaries support Turner

Step 3 management: In an otherwise healthy boy 14 yo with a family history of "late bloomers," delayed bone age, normal exam, a bone age film and a basic hormone panel are usually sufficient before reassurance and a 6-month follow-up. Do not order MRI or karyotype reflexively — let the gonadotropin pattern guide.

Diagnostic Workup — Advanced and Confirmatory Studies

— Mandatory in any girl with short stature and delayed puberty to evaluate for Turner syndrome (45,X and mosaics) — do this even if FSH is not yet elevated

— Indicated in boys with hypergonadotropic hypogonadism to confirm Klinefelter (47,XXY)

— Historically used to differentiate CDGP from congenital HH — a robust LH response suggests intact axis (CDGP), blunted response suggests HH

— In practice, inhibin B is a useful peripheral marker: low in HH, preserved in CDGP

— Indications: hypogonadotropic hypogonadism with anosmia, neurologic symptoms, visual field defects, headaches, panhypopituitarism, or polyuria/polydipsia

— Findings: olfactory bulb aplasia (Kallmann), craniopharyngioma, pituitary hypoplasia, infiltrative disease (LCH, sarcoid), germinoma

— Morning cortisol + ACTH stim (or low-dose ACTH test) for adrenal insufficiency

— GH provocation testing (clonidine, arginine, glucagon) if IGF-1 low and growth velocity poor

— ADH/water deprivation if polyuria

— AMH and inhibin B: Sertoli cell function in boys; ovarian reserve in girls

— 17-OH progesterone: nonclassic CAH (more for hirsutism, but overlap)

— Autoimmune panel: anti-ovarian, anti-adrenal antibodies in suspected polyglandular failure

Karyotype (cytogenetics):

GnRH stimulation test / GnRH agonist (leuprolide) stimulation:

MRI brain with pituitary protocol:

Pituitary axis testing if multi-hormone deficiency suspected:

Specialized markers:

Genetic panels: Increasingly used when congenital HH suspected — KAL1, FGFR1, PROK2, GNRHR, CHD7 (CHARGE)

CCS pearl: When workup reveals high gonadotropins in a phenotypic female with short stature, order karyotype and a screening echocardiogram + renal ultrasound — Turner syndrome carries bicuspid aortic valve, aortic coarctation, and horseshoe kidney risks that mandate cardiology and nephrology referrals before any estrogen therapy is initiated.

Risk Stratification and Management Logic

— Low LH/FSH + delayed bone age + positive family history + otherwise well → presumptive CDGP: watchful waiting or short-course sex steroid priming

— Low LH/FSH + normal bone age OR anosmia OR midline defect → congenital HH workup (MRI, genetics)

— Low LH/FSH + chronic disease markers → treat underlying disease first

— High LH/FSH → karyotype; manage as primary hypogonadism

— Urgent referral to pediatric endocrinology: any suspicion of intracranial mass, panhypopituitarism, ambiguous genitalia, or Turner syndrome

— Routine referral: all confirmed hypogonadism, persistent delay beyond 14 (boys)/13 (girls)

— Primary care managed: straightforward CDGP with reassurance

— Bullying, depression, school avoidance, body image distress

— Treatment may be indicated for psychosocial reasons even in CDGP — short courses of low-dose testosterone (boys) or estrogen (girls) accelerate visible puberty without compromising final height

— Klinefelter: counsel about TESE/sperm retrieval when older

— Congenital HH: pulsatile GnRH or gonadotropin therapy will be needed for fertility (not testosterone alone)

— Turner: oocyte cryopreservation may be possible early; counsel about pregnancy risks (aortic dissection)

Decision tree after initial workup:

Stratifying urgency:

Psychosocial risk stratification (often overlooked, board-tested):

Fertility considerations to discuss early:

Step 3 management: The triage question on exam is often "next best step" after initial labs. The pattern: low gonadotropins + delayed bone age + reassuring exam + positive family history = reassure and reassess in 6 months (or offer a 3- to 6-month course of low-dose testosterone for psychosocial distress). High gonadotropins = karyotype. Red flags = MRI brain.

Pharmacotherapy — First-Line Regimens

— Testosterone enanthate or cypionate 50–100 mg IM monthly × 3–6 months

— Goal: jump-start endogenous puberty, improve self-esteem, accelerate growth velocity without significantly advancing bone age

— After course, reassess endogenous puberty at 3–6 months off therapy

— Final adult height is not compromised when low doses are used

— Transdermal estradiol patch 3.1–6.2 mcg/day (¼ of a 25 mcg patch) or oral ethinyl estradiol 2–5 mcg/day × 3–6 months

— Reassess; if no progression after withdrawal, transition to definitive replacement (likely hypogonadism)

— Boys: start testosterone 50 mg IM monthly, increase every 6 months by 50 mg up to adult dose (~150–200 mg every 2 weeks); aim to match physiologic Tanner progression over 2–3 years

— Girls: start low-dose transdermal estradiol, escalate slowly over 2–3 years; add cyclic progesterone (medroxyprogesterone 5–10 mg days 1–12 of each month) after 2 years of estrogen or once breakthrough bleeding occurs, to protect endometrium

— Pulsatile GnRH pump (gold standard for hypothalamic HH) or

— hCG + recombinant FSH to induce spermatogenesis/ovulation

— Levothyroxine for hypothyroidism, cabergoline for prolactinoma, gluten-free diet for celiac, nutritional rehab and reduced exercise load for functional HH

Constitutional delay (boys) — short-course androgen priming:

Constitutional delay (girls) — short-course estrogen:

Permanent hypogonadism — full replacement (initiated and titrated by endocrinology):

Congenital HH wanting fertility:

Treating the underlying cause:

Board pearl: In a boy with CDGP and significant psychosocial distress, a short course of low-dose testosterone is appropriate and does NOT shorten final height — answer choices that say "testosterone will close growth plates prematurely" are distractors at low priming doses.

Expanded Pharmacology and Hormone Replacement Nuances

— Transdermal preferred over oral: bypasses first-pass hepatic metabolism, lower VTE risk, more physiologic IGF-1 effect, better for bone accrual

— Oral ethinyl estradiol acceptable when patches unavailable or adherence poor

— Avoid combined oral contraceptives during pubertal induction — supraphysiologic doses suppress growth potential

— Adding progesterone too early (<2 years of estrogen) blunts breast development

— Once added, can use cyclic medroxyprogesterone or transition to continuous combined HRT

— IM esters (enanthate, cypionate) are workhorses in adolescents — predictable, cheap

— Transdermal gels acceptable in later titration; avoid skin transfer to children/partners

— Long-acting undecanoate not first-line in pediatrics

— Boys: clinical Tanner staging, growth velocity, morning testosterone trough levels, hematocrit (polycythemia risk later), bone age every 6–12 months

— Girls: breast Tanner, growth, uterine size on US, estradiol levels, eventual induction of withdrawal bleed

— DXA at baseline if prolonged hypogonadism; ensure calcium 1300 mg/day, vitamin D 600–1000 IU/day

— Counsel on weight-bearing exercise

— Estrogen contraindicated in active thromboembolic disease, hormone-sensitive tumors, severe liver disease

— Testosterone caution with erythrocytosis, sleep apnea

— Both can affect mood; screen for depression at follow-up

Choosing estrogen route in girls:

Progesterone timing:

Testosterone formulations:

Monitoring during induction:

Bone health and adjunctive care:

Drug interactions/precautions:

Key distinction: Puberty induction is NOT contraception and NOT adult HRT — doses start low and escalate slowly to mimic physiologic puberty. Jumping straight to adult-dose oral contraceptives in a hypogonadal 13-year-old girl is wrong on the boards: it stunts growth, blunts breast development, and skips the dose-escalation principle.

Special Populations — Renal, Hepatic, and Chronic Disease

— Uremia suppresses GnRH and impairs gonadal response; growth failure plus pubertal delay is classic

— Treat with optimized dialysis/transplant, recombinant GH therapy (FDA-approved for CKD growth failure), and address acidosis, anemia, renal osteodystrophy

— Sex steroid replacement only after optimizing renal management

— Cirrhosis alters SHBG and sex steroid metabolism

— Avoid oral estrogen (hepatic first-pass) — use transdermal

— Wilson disease can present with amenorrhea/pubertal delay plus neuropsych and hepatic findings

— Among the most commonly missed causes of pubertal delay

— Even subclinical disease (mild anemia, modest weight-for-height drop) can cause functional HH

— Treat the bowel disease — puberty often resumes without sex steroids

— Chronic catabolic state + CFTR effects → delayed puberty in nearly all untreated patients

— Nutritional rehab and pancreatic enzyme replacement first

— Transfusional iron overload → hemosiderosis of pituitary → hypogonadotropic hypogonadism

— Screen with ferritin, MRI T2* of pituitary; chelation is preventive

— Cranial radiation >30 Gy → hypothalamic-pituitary damage (gonadotropin deficiency)

— Alkylating agents (cyclophosphamide, busulfan) → primary gonadal failure

— Pelvic radiation → ovarian/testicular failure

— All childhood cancer survivors need pubertal monitoring and pituitary axis screening

Chronic kidney disease (CKD):

Hepatic disease:

Inflammatory bowel disease and celiac:

Cystic fibrosis:

Sickle cell disease and thalassemia:

Cancer survivors:

Step 3 management: In a teen with IBD, anemia, mild weight-for-age drop, and no breast development at 14 — the next step is celiac/IBD workup and nutritional assessment, not gonadotropin testing. Functional HH from chronic disease is the rule, not the exception, and treating the disease is the treatment for the puberty.

Special Populations — Genetic Syndromes and Transgender Youth

— Begin low-dose estrogen at ~age 11–12 to time puberty with peers and optimize bone/uterine development

— Often combined with GH therapy from early childhood to improve final height

— Cardiac screening (echo, MRI) before pregnancy — aortic dissection risk is high

— Counsel about premature ovarian insufficiency and assisted reproduction

— Puberty often starts at normal age but fails to complete — testes don't grow beyond ~6 mL despite virilization

— Diagnosis typically age 12–14 with rising FSH; karyotype confirms

— Testosterone replacement from mid-puberty

— Sperm cryopreservation via microTESE discussed in late adolescence — fertility is possible

— Pubertal delay workup in a gender-diverse teen still requires evaluating organic causes

— GnRH analog (leuprolide) for pubertal suppression is a separate decision pathway involving multidisciplinary gender-affirming care teams

— Informed assent/consent involving patient, family, mental health support — do not initiate without comprehensive evaluation

— Female athlete triad / REDs: low energy availability, menstrual dysfunction, low bone density

— Treatment is restoring energy availability and reducing training load — oral contraceptives are NOT first-line and mask the problem

Turner syndrome (45,X and variants):

Klinefelter syndrome (47,XXY):

Prader-Willi syndrome: hypogonadism is multifactorial (hypothalamic + primary); coordinate with GH therapy already in place

Kallmann syndrome: Counsel on fertility recoverable with gonadotropins/GnRH, not with testosterone alone — important for family planning conversations

Transgender and gender-diverse youth (Step 3 relevant):

Athletic and eating-disorder populations:

Board pearl: Turner syndrome girls require cardiac and renal imaging at diagnosis and aortic surveillance lifelong — pregnancy in Turner carries up to 2% maternal mortality from aortic dissection; this counseling is a frequent Step 3 ethics/management item.

Complications and Adverse Outcomes

— Low peak bone mass → lifelong osteoporosis risk; pubertal years account for ~40% of adult bone mass

— Persistent open epiphyses → eunuchoid proportions

— Vertebral compression fractures in untreated young adults with severe hypogonadism

— Depression, anxiety, school refusal, bullying victimization

— Disordered eating worsens functional HH — a vicious cycle

— Long-term studies show lower educational attainment in untreated significant delay

— Hypogonadism is associated with central adiposity, insulin resistance, dyslipidemia, and earlier cardiovascular disease — especially in Klinefelter and Turner

— Turner: hypertension, bicuspid aortic valve, aortic dilation/dissection, premature CAD

— Infertility (most patients with congenital HH or primary gonadal failure require assisted reproduction)

— Counsel before initiating definitive replacement when fertility is desired in the future

— Testosterone: acne, mood swings, polycythemia (long-term), accelerated bone age if dosed too high

— Estrogen: VTE (especially oral), breakthrough bleeding, breast tenderness, rare hepatic adenoma

— Premature epiphyseal closure if sex steroids dosed at adult levels too early — major reason for low-dose escalation

— Undiagnosed craniopharyngioma → vision loss, panhypopituitarism, adrenal crisis

— Missed Turner → undetected aortic disease, untreated short stature window closes

— Missed Klinefelter → mental health, learning, and fertility windows missed

Skeletal complications (most clinically impactful):

Psychosocial and mental health:

Cardiometabolic:

Reproductive:

Iatrogenic complications of therapy:

Missed diagnoses (the worst complications):

CCS pearl: A teen on testosterone replacement who develops headache and progressive bitemporal vision loss may have an underlying mass that was never imaged — MRI brain is mandatory in any hypogonadotropic patient with neurologic symptoms regardless of how good the response to therapy looks.

When to Escalate — Referral, Consult, Inpatient Triage

— Suspected intracranial mass (headache, visual changes, polyuria/polydipsia, hyperprolactinemia)

— Panhypopituitarism (multiple hormone deficiencies including cortisol)

— Confirmed Turner or Klinefelter syndrome

— Ambiguous genitalia or significant exam discordance with reported sex

— Severe psychosocial distress requiring induction therapy

— Persistent delay beyond 14 (boys) / 13 (girls) without obvious functional cause

— Hypergonadotropic hypogonadism of any cause

— Persistent hypogonadotropic hypogonadism after 6-month observation

— Need for puberty induction or replacement

— Disordered eating, REDs, severe body image distress

— Suspected gender dysphoria

— Confirmed chromosomal abnormality, suspected congenital HH, syndromic features

— Any Turner syndrome (echo, then MRI by adolescence)

— Suspected aortic root dilation

— Pituitary apoplexy or large symptomatic sellar mass — neurosurgery + endocrinology

— Adrenal insufficiency from secondary cortisol deficiency — IV hydrocortisone

— Diabetes insipidus with hypernatremia

— Severe malnutrition from eating disorder requiring refeeding under monitoring (electrolytes, refeeding syndrome)

— Bullying, academic accommodations, mental health support

— Family education and expectation setting

Urgent pediatric endocrinology referral (within days to weeks):

Routine pediatric endocrinology referral (weeks):

Adolescent medicine/psychiatry referral:

Genetics referral:

Cardiology referral:

Inpatient admission criteria (uncommon but board-relevant):

Social work and school counselor involvement:

Step 3 management: In a 15-year-old boy with headaches, weight gain, growth arrest, and no pubertal signs, the next step is MRI brain with pituitary protocol AND morning cortisol — do not give testosterone until adrenal sufficiency is confirmed; precipitating adrenal crisis is a real and tested complication.

Key Differentials — Same-Category Causes (Hypogonadism Types)

— Constitutional delay (CDGP): transient, familial, normal sense of smell, eventual spontaneous puberty

— Congenital HH (normosmic): mutations in GNRHR, KISS1R, TAC3 — permanent

— Kallmann syndrome: congenital HH with anosmia/hyposmia — KAL1, FGFR1, PROK2, CHD7

— Functional HH: chronic illness, malnutrition, eating disorders, overtraining, opioid use, glucocorticoid excess

— Acquired pituitary disease: craniopharyngioma, pituitary adenoma (prolactinoma), Rathke cleft cyst, germinoma, histiocytosis, sarcoidosis, lymphocytic hypophysitis, hemochromatosis, post-radiation, post-traumatic

— Hypothyroidism (primary, severe): elevated TRH cross-stimulates prolactin → suppresses GnRH (van Wyk-Grumbach in extreme cases)

— Hyperprolactinemia: prolactinoma, antipsychotics, stalk effect

— Cushing syndrome: endogenous or exogenous glucocorticoid suppression

— Turner syndrome (45,X)

— Klinefelter syndrome (47,XXY)

— Pure gonadal dysgenesis (46,XX or 46,XY — Swyer)

— Premature ovarian insufficiency: autoimmune (often with adrenal/thyroid), galactosemia, FMR1 premutation

— Anorchia/vanishing testes

— Iatrogenic gonadal damage: chemotherapy (alkylators), pelvic/gonadal radiation, surgery

— Mumps orchitis, autoimmune oophoritis

— Noonan syndrome (boys with cryptorchidism)

Hypogonadotropic (central) hypogonadism — low LH/FSH, low sex steroid:

Hypergonadotropic (primary gonadal) hypogonadism — high LH/FSH, low sex steroid:

Key distinction: CDGP vs congenital normosmic HH is the most-tested differential in this topic — both have low LH/FSH and low sex steroids in a healthy adolescent. CDGP eventually progresses spontaneously; congenital HH does not. Distinguishing features include positive family history, transient nature, and preserved inhibin B in CDGP — but definitive distinction may require 6–12 months of observation off therapy.

Key Differentials — Other-Category Mimics

— Constitutional short stature without pubertal delay: familial short stature with normal Tanner progression for bone age — these kids are short but puberty is on track

— Familial short stature: mid-parental height predicts short adult height; bone age = chronologic age; no hypogonadism

— Idiopathic short stature: normal labs, normal puberty timing, just short

— Growth hormone deficiency: poor growth velocity prominent; puberty may be normal or delayed; IGF-1 low

— Müllerian agenesis (MRKH): normal breast and pubic hair development, absent uterus/upper vagina, normal female karyotype, normal estrogen — pelvic exam/US diagnoses

— Androgen insensitivity syndrome (complete): 46,XY phenotypic female, breast development from aromatized estrogen, absent pubic/axillary hair, blind vaginal pouch, intra-abdominal testes — karyotype and testosterone confirm

— Imperforate hymen / transverse vaginal septum: cyclic pain, hematocolpos — outflow obstruction, normal hormones

— Isolated premature adrenarche: pubic/axillary hair without true puberty — often confused but is precocious, not delayed

— Eating disorder masquerading: restrictive intake suppressing GnRH; the diagnosis hides behind the puberty complaint

— Chronic systemic disease without obvious symptoms: celiac, IBD, JIA, untreated diabetes, untreated CF

— Chronic opioids → HH

— Chronic high-dose glucocorticoids → growth and puberty suppression

— Antipsychotics (risperidone) → hyperprolactinemia

— Cannabis (heavy use) → suppression

Conditions that look like delayed puberty but aren't true hypogonadism:

Conditions presenting as primary amenorrhea (girls) that aren't classic delayed puberty:

Conditions causing apparent delay:

Drug-induced:

Board pearl: A 16-year-old phenotypic girl with normal breast development, sparse pubic hair, primary amenorrhea, and a blind vaginal pouch has complete androgen insensitivity (46,XY) — not delayed puberty. This is the classic exam stem distinguishing pubertal failure from anatomic/genetic mimics; karyotype and serum testosterone (in male range) clinch it.

Long-Term Plan and Transitions

— Document spontaneous progression at 6-month intervals

— Discharge from endocrinology once Tanner 4 reached and growth velocity peaks

— Final adult height typically within mid-parental target range — no long-term medications

— Continue sex steroid replacement indefinitely (with reproductive interruptions if fertility pursued)

— Transition to adult endocrinology by ages 18–21 — a documented handoff is a Step 3 quality-of-care point

— Provide a written summary: diagnosis, genetics, replacement regimen, complications, fertility plan

— DXA at end of puberty induction and every 2–3 years; ensure calcium 1300 mg/day, vitamin D 600–1000 IU/day, weight-bearing activity

— Address persistent low BMD with optimization of sex steroids before considering bisphosphonates

— Annual BP, lipids, fasting glucose/A1c — especially Turner, Klinefelter, panhypopituitarism

— Turner: lifelong aortic surveillance (echo or MRI per syndrome guidelines), thyroid screening, liver enzymes, audiology

— Discuss fertility options proactively — gamete cryopreservation, gonadotropin/pulsatile GnRH therapy for HH, microTESE for Klinefelter, oocyte preservation for early POI/Turner

— Contraception counseling for those with intermittent fertility (Klinefelter sometimes, mosaic Turner)

— Continued screening for depression, anxiety, body image

— Support groups (Turner Syndrome Society, AXYS for Klinefelter)

For CDGP — long-term plan:

For permanent hypogonadism — lifelong replacement:

Bone health surveillance:

Cardiometabolic prevention:

Reproductive planning:

Mental health and identity:

Step 3 management: A structured transition plan from pediatric to adult endocrinology between ages 18–21 is a recognized quality measure — failure to transition is associated with replacement non-adherence, lost-to-follow-up Turner aortic catastrophes, and untreated osteoporosis. Document the handoff explicitly in the chart.

Follow-Up, Monitoring, and Counseling

— CDGP observation: every 6 months until clear pubertal progression

— Active puberty induction: every 3–6 months — clinical Tanner, growth velocity, weight, BP, mood

— Stable replacement: every 6–12 months

— Boys on testosterone: trough total testosterone (mid-cycle for IM), CBC (hematocrit), lipid panel annually, bone age until epiphyses fuse

— Girls on estrogen: estradiol level, screen for breakthrough bleeding, lipids; once on combined HRT, no routine endometrial surveillance unless symptomatic

— Annual: TSH, A1c if at risk (Turner especially), liver enzymes, vitamin D

— Bone age every 6–12 months until skeletal maturity

— DXA at completion of puberty

— Turner: echocardiogram in childhood, MRI aorta by adolescence and then every 5 years (more often if dilation)

— Adherence: especially during transition years; missed testosterone doses cause fatigue, mood changes, bone loss

— Sick-day rules for those with concomitant adrenal insufficiency (stress-dose hydrocortisone)

— Fertility windows and cryopreservation timing

— Driving, sports, school accommodations during induction

— Sexual health: address sexual development questions, STI prevention, contraception

— Family planning: genetic counseling for inheritable forms (Kallmann is often autosomal dominant with variable penetrance)

— Screen for depression (PHQ-A) at every visit during induction

— School performance, peer relationships, bullying

— Refer to therapy as needed; involve family

Follow-up cadence:

Laboratory monitoring during therapy:

Imaging surveillance:

Counseling — must-cover topics:

Psychosocial follow-up:

CCS pearl: In CCS-style scenarios, a delayed puberty teen's optimal follow-up sequence is: confirm pubertal progression at 6-month intervals, advance imaging only when indicated, and document height velocity at every visit — premature reassurance without growth-velocity confirmation is a common scored error.

Ethical, Legal, and Patient Safety Considerations

— Pubertal induction and replacement therapy involve adolescents — engage them directly, obtain assent alongside parental consent

— Discuss fertility implications before therapy begins; document the conversation

— Genetic findings (Klinefelter, Turner) carry implications for siblings and future children — offer genetic counseling before testing

— Adolescent confidentiality laws vary by state — sexual health, contraception, mental health often confidential

— Genetic disclosure to family members requires patient agreement

— Delayed puberty from severe restrictive eating or suspected neglect (failure to seek care for obvious chronic disease) may trigger child protective services reporting

— Suspected abuse contributing to growth/pubertal failure (psychosocial dwarfism) — mandatory report

— Failure to transition from pediatric to adult endocrinology is a leading cause of replacement gaps and aortic deaths in Turner syndrome

— Use a written transition document; confirm first adult appointment scheduled before pediatric discharge

— Avoid reflexive MRI in clear CDGP — but never miss a true intracranial mass

— Bone age radiation exposure is minimal; appropriate use is safe

— Aromatase inhibitors and GH augmentation in CDGP remain investigational — frame as such if asked

— Pubertal suppression for gender-diverse youth: requires multidisciplinary team, formal consent process, psychological evaluation, and ongoing monitoring; avoid initiating in primary care alone

— Cost of long-term replacement and growth hormone — insurance authorization is part of the care plan

— Cultural and family attitudes toward delayed development; trauma-informed approach

Informed consent and adolescent assent:

Confidentiality issues:

Mandatory reporting:

Transition-of-care safety (Step 3 priority):

Imaging stewardship:

Off-label and emerging therapies:

Equity considerations:

Board pearl: A 13-year-old girl with anorexia nervosa, weight loss, and amenorrhea who refuses nutritional rehab is not a candidate for oral contraceptives to "induce periods" — the answer is nutritional restoration and treatment of the eating disorder; prescribing OCPs masks the disease, fails to restore bone, and is a recognized Step 3 trap.

High-Yield Associations and Rapid-Fire Facts

— Short girl + delayed puberty + webbed neck + bicuspid aortic valve → Turner syndrome

— Tall boy + small firm testes + gynecomastia + learning issues → Klinefelter syndrome

— Delayed puberty + anosmia → Kallmann syndrome

— Delayed puberty + headache + bitemporal hemianopsia → craniopharyngioma

— Delayed puberty + galactorrhea → prolactinoma

— Delayed puberty + cold intolerance + bradycardia → severe hypothyroidism

— Delayed puberty + cyclic abdominal pain + breast development → outflow obstruction (imperforate hymen)

— Delayed puberty + family history of late bloomers + delayed bone age → CDGP

— Female athlete + low BMI + amenorrhea + stress fractures → female athlete triad/REDs

— 46,XY + female phenotype + breast development + no pubic hair + blind vaginal pouch → complete androgen insensitivity

— Low LH/FSH + delayed bone age + normal smell + good family history → CDGP

— Low LH/FSH + anosmia → Kallmann

— High LH/FSH + short stature + female phenotype → Turner (karyotype)

— High LH/FSH + tall + male phenotype → Klinefelter (karyotype)

— Normal LH/FSH + uterus absent + 46,XX → MRKH

— Normal/high testosterone + female phenotype + 46,XY → AIS

— Testicular volume ≥4 mL = puberty has begun

— Breast budding (Tanner 2) = puberty has begun in girls

— Bone age delay protects future height potential

— Inhibin B preserved in CDGP, low in congenital HH

— Pulsatile GnRH or hCG/FSH (not testosterone) restores fertility in central HH

— Turner pregnancy → aortic dissection risk

— Cranial radiation >30 Gy → hypothalamic-pituitary damage

Pattern recognition shortcuts:

Lab pattern lightning round:

Pearls:

Key distinction: Adrenarche (pubic/axillary hair, body odor) is NOT the same as gonadarche (testicular/breast development) — adrenarche without gonadarche by age 14/13 still meets the definition of delayed puberty and requires workup.

Board Question Stem Patterns

— 14-year-old boy, height at 5th percentile, testes 3 mL, no pubic hair, normal exam, father shaved at 17, mother menarche at 15. Bone age 12 years. Labs: low LH/FSH/testosterone, normal TSH/IGF-1. Best next step: reassurance, follow-up in 6 months.

— 14-year-old girl, height <3rd percentile, webbed neck, no breast development. FSH elevated. Best next step: karyotype (Turner). Then echocardiogram and renal US.

— 15-year-old boy, no pubertal development, anosmia, normal height. Low LH/FSH/testosterone. Best next step: MRI brain with pituitary protocol (Kallmann/CHARGE workup).

— 14-year-old girl, no menses, no breast development, chronic abdominal pain, anemia, low BMI, positive TTG-IgA. Best next step: gluten-free diet — celiac is causing functional HH.

— 16-year-old elite runner, primary amenorrhea, BMI 17, stress fractures. Best next step: nutritional rehab and reduced training, NOT oral contraceptives.

— 16-year-old girl, breast development normal, sparse pubic hair, primary amenorrhea, blind vagina. Best next step: karyotype and serum testosterone — distinguish MRKH (46,XX) from CAIS (46,XY).

— 15-year-old boy with delayed puberty, headache, polyuria. Best next step: MRI brain and morning cortisol — replace cortisol before testosterone to avoid precipitating adrenal crisis.

— 18-year-old with Turner syndrome on estrogen replacement aging out of pediatric care. Best next step: structured transition to adult endocrinology with cardiology surveillance documented.

Stem pattern 1 — "Reassure and observe":

Stem pattern 2 — "Karyotype":

Stem pattern 3 — "MRI brain":

Stem pattern 4 — "Treat the underlying disease":

Stem pattern 5 — "Restore energy availability, not OCPs":

Stem pattern 6 — "Karyotype in apparent female with absent uterus":

Stem pattern 7 — "Hold off on testosterone":

Stem pattern 8 — "Transition planning":

Step 3 management: Question stems reward recognizing the chronic disease or genetic syndrome behind the delayed puberty — the "next best step" is almost never to give a sex steroid first; it is to classify the axis (LH/FSH pattern), obtain bone age, and pursue the cause before any therapy.

One-Line Recap

Delayed puberty workup centers on classifying the HPG axis — low gonadotropins point toward CDGP or central causes (with MRI and bone age guiding), while high gonadotropins demand a karyotype to identify Turner or Klinefelter, and chronic disease/functional causes must always be excluded before sex steroid therapy is offered.

— Low LH/FSH → CDGP (most common), congenital HH/Kallmann (anosmia), functional HH (chronic disease), pituitary mass

— High LH/FSH → karyotype: Turner (girls), Klinefelter (boys), POI, gonadal damage

Definitions to memorize: No testicular enlargement by 14 in boys, no breast budding by 13 in girls (or no menarche by 15) = delayed puberty.

First-line workup: Bone age + LH, FSH, testosterone/estradiol, TSH, prolactin, IGF-1, CBC, CMP, ESR, TTG-IgA — this panel alone classifies most patients into central vs primary vs functional vs chronic disease.

Categorize the gonadotropins:

Treatment principles: Treat underlying disease first; for CDGP, reassure or offer short low-dose androgen/estrogen priming; for permanent hypogonadism, induce puberty with low-dose escalating sex steroids over 2–3 years (transdermal estrogen preferred in girls); pulsatile GnRH or hCG/FSH for fertility in central HH.

Surveillance and transition: Bone health, cardiometabolic risk, Turner aortic surveillance, fertility counseling, mental health screening, and a documented handoff to adult endocrinology by ages 18–21.

Board pearl: When in doubt on a stem, the right next step is rarely a hormone prescription — it is bone age, hormone classification, or imaging/karyotype based on red flags. Treating before classifying is the single most common Step 3 trap in this topic.