Q: Is administration of GnRH analogues advisable in case of a 9 year old girl who has just had menarche? Her present height is 4 feet 9 inches. Both the maternal and paternal family members are tall. What could be the prospective final height without GnRH therapy? Would the administration of GnRH analogues significantly increase the possibility of growth in terms of height? Does GnRH therapy have any long term after effects?

A:Administration of GnRH analogues certainly helps to improve height gain in children, especially boys with central or true form of precocious puberty. There are no prediction models to state how much height will be achieved by such therapy. Girls reportedly gain as much as 1-5 cm by such therapy. A mild case near the age of normal puberty might be an inappropriate subject for such therapy. Thus this child at 9 years may not benefit very much especially in height with GnRH analogue. However evaluation of the stage of puberty, estimation of levels of sex hormones (whether in advanced pubertal levels or not) and estimation of bone age will be good indicators of benefit to such therapy. Several preparations of GnRH agonist analogues are available for therapy with daily or monthly dosing. Local allergic reactions and sterile abscesses are seen in about 5% cases, but very rare in my experience. Serious other side effects are rare. The risks for long term side effects are low.