The effect of low dose oestrogens on short-term growth and concomitant biochemical phenomena in girls with tall stature.

Using a simple non-invasive ulnar length measuring technique a 70 to 80% decrease in ulnar growth velocity was found during one interval of 9 weeks of low dose ethinyloestradiol administration (0.050 mg daily) in girls with tall stature. This decrease in ulnar growth velocity was found to be statistically significant within 6 and even 3 weeks after starting oestrogen loading whereas the change in body growth velocity was only significant after 9 weeks. After interpreting oestrogen administration, ulnar growth velocities increased again but to values tending to be lower than before ethinyloestradiol loading. Serum alkaline phosphatase activities and plasma inorganic phosphorus and calcium levels also decreased significantly during oestrogen therapy within 9 weeks. The results found illustrate that the measuring technique used enables evaluation of the short-term effect of hormonal treatment on growth and thereby related biochemical phenomena.