Pocket ObGyn – Precocious Puberty

Dec 8, 2019 admin PHỤ KHOA, SẢN KHOA 0

Pocket ObGyn – Precocious Puberty
See Abbreviations

Definition (N Engl J Med 2008;358:2366)

  • Dev of breast or pubic hair >5 SD below mean age.Traditional definition <8 yo. Trend of decreasing age of puberty ® now <7 yo in C girls, <6 y in AA girls (Pediatrics 1997;99:505; Pediatrics 1999;104:936).
Initial Workup
  • Hx: Onset, family members’ ages of puberty, h/o neurologic dz or trauma, exposure to sex steroids, headache, sz, abdominal pain
  • PE: Height, weight, growth chart,Tanner staging, fundoscopic exam (papilledema in ­

intracranial pres), visual field eval (sellar mass lesion), skin exam.

  • Bone age eval: Plain film X-ray of left hand & wrist
  • Lab eval: Basal LH, LH following GnRH stimulation, FSH, estradiol LH <1 IU/L = premature thelarche or nml

LH >0.3 IU/L = true precocious puberty

LH >5 mIU/L = central (gonadotropin-dependent) precocious puberty

Treatment Goals
  • Postpone dev until nml pubertal age, maximize adult height, reduce risk of psychosocial problems a/w early sexual maturation
Gonadotropin-dependent (Central) Precocious Puberty (GDPP)
  • Early maturation of HPO axis ® breast & pubic hair dev, w/ usually nml sequence of pubertal events at nml pace, & isosexual (appropriate for gender)
  • Etiology: Idiopathic – 90%; dx of CNS lesions – tumors, irradiation, hydroceph- alus, cysts, trauma, inflamm dz, midline developmental defects. Sev hypothyroidism (rare).
  • Dx: Accelerated linear growth for age (>75% of height at dx), advanced bone age, pubertal levels of FSH, LH, estradiol, & ­ w/ GnRH stimulation MRI in all pts to evaluate for CNS lesion.TFTs if clinical concern for hypothyroidism. Evaluate ¯ growth hormone if h/o cranial irradiation. Abdominopelvic US – repeated exposure to sex steroids from periph sources can induce secondary premature maturation of HPO axis.
  • Rx: Treat intracranial lesions or hypothyroidism if Idiopathic GDPP, treat if: sexual maturation progresses to next stage w/i 3–6 mo,

onset puberty <6 yo, growth velocity >6 cm/y,

Bone age advanced by 1 y or more, or

predicted adult height below target range or decreasing on serial determinations. Long-acting GnRH agonist ® prepubertal hormone level, prevents pubertal dev,

growth acceleration, & bone advancement (N Engl J Med 1981;305:1546). Treat until epiphyses fused or pubertal & chrono ages are appropriately matched.

Gonadotropin-independent (Peripheral) Precocious Puberty

  • Due to excess exposure of sex steroid hormones from gonads, adrenals, or May be contrasexual or isosexual. Pubertal sequence progression may be altered.
  • Etiology: Functional ovarian follicular cysts – most common cause, w/ transient breast dev & vaginal bleeding, 1+ unilateral or bilateral ovarian cysts >15 mm, bone age Ovarian tumors (rare) – granulosa cell tumor ® isosexual, Leydig cell/gonadoblastoma

® contrasexual. Adrenal – androgen-secreting tumors, CAH. McCune–Albright

Gonadotropin- independent precocious puberty
Gonadotropin- dependent precocious puberty
Observation, serial exams

syndrome (rare) – triad of periph precocious puberty, café-au-lait spots, fibrous bone dysplasia ® recurrent formation of follicular cysts & cyclic vaginal bleeding.

  • Dx: Low or nml FSH & LH levels, do not ­ w/ GnRH Labs: Testosterone, estradiol, FSH, afternoon cortisol (screen Cushing syn), DHEA, DHEAS, 17-OHP (screen CAH). Abdominopelvic US for ovarian cyst/tumor.
  • Rxs: Surgical removal (tumor); tamoxifen for vaginal bleeding, bisphosphonate for bone dysplasia; aromatase inhibs lack long-term effectiveness; exogenous estrogens as cream, ointment, spray (contrasexual); remove exogenous source; for functional cysts ® observation, usually self-limited, surgical removal if persistent or torsion; GnRH agonist ineffective for gonadotropin
Isolated Precocious Puberty
  • Isolated premature thelarche or Usually benign nml variants. If bone age nml, precocious puberty unlikely.
  • Expectant mgmt w/ re-evaluation at 6 ~20% progress to gonadotropin- dependent precocious puberty. Requires regular exams.
  • Isolated premature thelarche: Unilateral or bilateral, <8 y, absence of other secondary sexual characteristics, nml linear growth, nml bone Estradiol level usually prepubertal – girls typically <3 yo, nonobese. Unk cause.
  • Isolated premature adrenarche: Isolated pubic &/or axillary hair <8 Dx: DHEA-S appropriate for pubic hair stage. Girls typically overweight. 17-OHP & testosterone appropriate for age. Bone age & growth rate ­ but w/i nml limits. Risk factor for PCOS. Further w/u: ACTH stimulation to r/o CAH when bone age advanced, predicted adult height abnormally low, or serum testosterone & DHEA-S elevated – may be only manifestation of mild CAH. Rx: Observation, regular exams to detect other signs of precocious sexual dev.
Isolated precocious puberty
Breast OR pubic hair AND accelerated growth
Breast OR pubic

hair only
Breast AND pubic hair
GnRH stimulation test

Figure 6.2 Approach to precocious puberty

 

 

 

 

 

 

 

 

 

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