A multicentre trial of recombinant growth hormone and low dose oestrogen in Turner syndrome: near final height analysis.

BACKGROUND Turner syndrome accounts for 15-20% of childhood usage of growth hormone (GH) in the UK but final height benefit remains uncertain. The most effective strategy for oestrogen replacement is also unclear. METHODS Fifty eight girls who, at start of treatment, were of mean age 9.1 years and projected final height 142.2 cm were randomised to receive in year 1, either low dose ethinyloestradiol 50-75 ng/kg/day, GH 28 IU/m(2) surface area/week as a daily injection, or a combination of ethinyloestradiol and GH. After the first year, the ethinyloestradiol treated girls received combination treatment. After two years, girls aged over 12 years were given escalating ethinyloestradiol to promote pubertal development. RESULTS Near final height was available for 49 girls at age 16.5 years, 146.8 cm, representing a gain of 4.6 cm, range -7.9 to +11.7 cm. Twelve of the 49 girls gaining 7.5 cm or more were less than 13 years at the start and had received GH for at least four years. Height gain was correlated with greater initial height deficit. Fifteen girls (31%) reached 150 cm or more compared to a predicted 10%. Early supplementation with ethinyloestradiol provided no final height advantage. CONCLUSIONS Final height gain was modest at 4.6 cm. Younger, shorter girls gained greatest height advantage from GH. Low dosage ethinyloestradiol before planned induction of puberty was not beneficial.