207- How to monitor a child with precocious puberty on GnRH agonist therapy?
Children with GDPP receiving GnRH agonist should be monitored for pubertal
status, height velocity, and any treatment-related adverse events every three
monthly. Hormonal evaluation should be performed after 8–12 weeks of initia-
tion of therapy and every 3–6 monthly, thereafter. Bone age should also be
assessed annually in these children.- What is the predicted clinical response to GnRH agonist in a child with preco-
cious puberty?
Optimal therapy with GnRH agonist results in reversal of almost all features of
precocity in girls including regression of breast size and pubic hair, cessation of
menses, and reduction in ovarian and uterine volume. However, appearance of
pubic hair while on therapy with GnRH agonist does not necessarily mean failure
of therapy, as these agents have no effect on adrenal androgen synthesis. In boys,
there is a decrease in testicular volume, thinning of pubic hair, resolution of acne
and seborrhea, and improvement in aggressive behavior. These clinical improve-
ments are evident within 6 months of initiation of therapy. Height velocity steadily
decreases in the initial years of therapy, accompanied with retarded progression
of bone age. In a study, it was shown that mean height velocity decreased from
pretreatment value of 8.4 cm/year to 5.9 cm/year after 1 year of therapy with
GnRH agonist, 5.3 cm/year after 2 years and 4 cm/year thereafter. Bone matura-
tion was slowed, and the mean increase in bone age was 0.5 year per year. - What are the predictors of optimal adult height in a child with GDPP at the
initiation of GnRH agonist therapy?
The predictors of optimal adult height in a child with GDPP at initiation of
GnRH agonist therapy include younger age (<6 years), greater height at initia-
tion of therapy, higher predicted adult height (based on bone age), and greater
target height. - What is the role of GH therapy in children with precocious puberty treated with
GnRH Agonist?
Children with GDPP who have significant advancement of bone age irrespec-
tive of age of presentation may be considered for rhGH therapy along with
GnRH agonist to attain final adult height, though evidence for the use of rhGH
therapy is limited. - What is the predicted biochemical response to GnRH agonist therapy in a child
with precocious puberty?
Therapy with GnRH agonist results in an initial “flare,” characterized by rise in
FSH, LH, and gonadal steroids within 1–3 days of administration. This may
manifest clinically as priapism in boys and vaginal bleed in girls. The initial
flare is followed by inhibition of pulsatile secretion of FSH and LH within
6 Precocious Puberty