Sexual Development Flashcards
What is puberty?
Puberty” - begins with the earliest signs of sexual maturity and lasts until physical, mental and emotional maturation occur
What is the onset of puberty in girls and boys?
GIRLS – average onset at 9, peak height velocity at 11.5 (range: 9.7-13.5)
BOYS - average onset at 11, peak height velocity at 13.5 (range: 11.7-15.3)
how much adult height is accounted for in puberty? adult weight?
25% of final adult height is accounted for during pubertal growth
More than 40% of the ideal adult weight is accounted for during puberty
What is the SMR?
The Sexual Maturity Rating (SMR) measures the stages of secondary sexual characteristics
- Also known as the Tanner Staging System
- Assigns a Tanner stage of 1 (prepubertal) to 5 (adult)
- For boys it is based on genitalia and pubic hair
- For girls it is based on breast development and pubic hair
- Completion takes approximately 4-5 years
What does sexual development begin with in girls? in boys?
girls:
Begins with the growth of breast buds (thelarche) and pubic hair growth (pubarche)
boys:
First sign is scrotal corrugation and pigmentation, along with testicular enlargement
when does the growth spurt happen in girls? boys?
girls = stage 3 boys = stage 4
What are some normal variants of puberty?
- breast asymmetry and masses
- Physiologic Leukorrhea (clear discharge)
- Irregular Menses
Girls can have irregular periods for 2 to 5 years after the first menstrual period. - Gynecomastia (normal in adolescents and babies)
What is precocious puberty?
Signs of puberty before age 8 in girls and before age 9 in boys
What is delayed puberty?
Children who show no signs of puberty by age 13 (girls) or 14 (boys)
What is bone age and how is it measured?
Skeletal maturity, or bone age, can be estimated from radiographs of the left hand and wrist.
From this radiograph, the bone age can be estimated and adult height can be predicted
calendar age
sex and
height
information about the parents
What are the three main categories of pubertal delay?
Constitutional delay in growth
Hypogonadotropic hypogonadism
Hypergonadotropic hypogonadism
What is the most common cause of delayed puberty?
Constitutional delay in growth
describe Constitutional delay in growth
Normal variant!
Often have FHx of pubertal delay
Delayed bone age with no evidence of endocrinopathy or other organic disease
Diagnosis of EXCLUSION
Describe Hypogonadotropic hypogonadism
aka CENTRAL HYPOGONADISM
Defect at the level of the hypothalamus or pitutiary
Results in deficient GnRH or gonadotropin secretion
Low basal LH and FSH
Absence of appropriate LH response to exogenous GnRH
What are some causes of Hypogonadotropic Hypogonadism?
Kallman syndrome, problem with pit/hypothalamus, or systemic disease.
Describe Hypergonadotropic Hypogonadism
aka PRIMARY hypogonadism
Defect at the level of the gonads
Serum concentrations of gonadotropins ( particularly FSH) elevated in children >10 yrs
Primary testicular failure: Klinefelter’s syndrome (XXY) XY gonadal dysgenesis Anorchia Cryptorchidism Post chemotherapy or local irradiation
What are some syndromes that are Hypergonadotropic Hypogonadism related?
Ovarian failure: Turner syndrome (45XY or XO) Testicular failure: Klinefelter syndrome (47XXY) Autoimmune disease
What is the treatment for pubertal delay for constitutionally delayed adolescents?
In constitutionally delayed adolescents
Observation and reassurance is appropriate
In males, short-term hormonal therapy may be useful
Testosterone enanthate
No longer than 4-8 months
How do you eval for pubertal delay?
- recognize delayed puberty (>13 or >14)
- get basal plasma gonadotropin levels (LH, FSH)
- Is it high or low?
If High…then hypergonadtropic hypogonadism (primary ovarian or testicular failure)…KARYOTYPE looking for turners or kleinfelters
If low or normal, the LH response to GnRH
- if no response = hypogonadtropic hypogonadisms or organic or functional cause
- if response then = constitutional delay aka normal variant
Why does sexual precocity occur?
Results from an increase in circulating sex steroids
what are two sources for sexual precocity?
Etiologic considerations may be divided into endogenous and exogenous sources:
1. Endogenous
Gonads, adrenal cortex
- Exogenous
Estrogen-containing creams, birth control pills, anabolic steroids, excessive fat tissue (fat makes estrogen)
who is sexual precocity more common in?
girls
What causes sexual precocity in girls?
Central precocity :
Often idiopathic
Can be due to CNS abnormalities
Primary or peripheral precocity:
Ovarian abnormalities
Adrenal hyperplasia
What are the causes of sexual precocity in boys?
Much less common
Peripheral and central are equally common
The younger the child with precocity, the higher the likelihood of CNS abnormality
What are two causes of primary precocity in boys?
McCune Albright Syndrome
Genetic mutation causing hypersecretion of hormones
Leydig cell hyperplasia
Genetic mutation causing testicular production of testosterone without LH stimulation (testotoxicosis)
What is the workup for precocious puberty?
Extensive hormonal workup is needed to evaluate cause of precocity in both boys and girls
-GnRH, FSH, LH, Estrogen, Progesterone (females)
-GnRH, FSH, LH, Testosterone (boys)
Bone Age (X-ray of Left Wrist)
Endocrine Referral
Treatment targeted at specific etiology and varies widely
Usually managed by Endocrine
does menarche occur early or late in puberty? what is the mean age for menarche? what does it signify?
late
12.8
closure of the epiphyseal plates
