Nonprogressive precocious puberty | Central precocious puberty | Peripheral precocity | |
Physical examination: Advancement through pubertal stages (Tanner stage) | No progression in Tanner staging during 3 to 6 months of observation | Progression to next pubertal stage in 3 to 6 months | Progression |
Growth velocity | Normal for bone age | Accelerated (>6 cm per year)* | Accelerated* |
Bone age | Normal to mildly advanced | Advanced for height age | Advanced for height age |
Serum estradiol concentration (females)¶ | PrepubertalΔ | Prepubertal to pubertal | Increased in ovarian causes of peripheral precocity or with exogenous estrogen exposure |
Serum testosterone concentration (males, or females with virilization)¶ | PrepubertalΔ | Prepubertal to pubertal | Pubertal and increasing |
Basal (unstimulated) serum LH concentration¶ | PrepubertalΔ◊ | Pubertal◊ | Suppressed or prepubertal◊ |
GnRH (or GnRH agonist) stimulation test¶ | LH peak in the prepubertal rangeΔ§ Lower stimulated LH:FSH ratio¥ | LH peak elevated (in the pubertal range)§ Higher stimulated LH:FSH ratio¥ | No change from baseline or LH peak in the prepubertal range |
CPP: central precocious puberty; LH: luteinizing hormone; GnRH: gonadotropin-releasing hormone; FSH: follicle-stimulating hormone.
* Unless the patient has concomitant growth hormone deficiency (as in the case of a neurogenic form of CPP) or has already passed their peak height velocity at the time of evaluation, in which case, growth velocity may be normal or decreased for chronologic age.
¶ Using most commercially available immunoassays, serum concentrations of gonadal steroids have poor sensitivity to differentiate between prepubertal and early pubertal concentrations.
Δ In most cases, these levels will be prepubertal; however, in children with intermittently progressive CPP, these levels may reach pubertal concentrations during times of active development.
◊ Using ultrasensitive assays with detection limit of LH <0.1 mIU/L, prepubertal basal LH concentrations are <0.2 to 0.3 mIU/L.
§ In most laboratories, the upper limit of normal for LH after GnRH stimulation is 3.3 to 5.0 mIU/mL. Stimulated LH concentrations above this normal range suggests CPP.
¥ A peak stimulated LH:FSH ratio <0.66 usually suggests nonprogressive precocious puberty, whereas a ratio >0.66 is typically seen with CPP[1].