Effect of Treatment with Cyproterone Acetate on Uterine Bleeding at the Beginning of GnRH Analogue Therapy in Girls with Idiopathic Central Precocious Puberty

Seminara, S.
Nanni, L.
Generoso, M.
Mirri, S.
Leonardi, V.
Slabadzianiuk, T.
Vetrano, M. L.
Buongiorno, A.
Losi, S.
Galluzzi, F.

Paediatric Endocrinology Unit, Department of Paediatrics, University of Florence, AOU Meyer, Florence, Italy

Received April 16, 2009; Accepted July 31, 2009; previously published online April 14, 2010

Hormone Research in Paediatrics 73(5):p 386-389, April 2010. | DOI: 10.1159/000308172

Abstract

Background:

The flare-up effect of GnRH analogues may cause transient uterine bleeding in girls affected with idiopathic central precocious puberty (ICPP).

Aims:

To assess the incidence of endometrial bleeding and verify whether pretreatment with cyproterone acetate could counteract it.

Methods:

Fifty-four girls affected by ICPP were divided into 2 groups. The first group (30 girls) was treated with triptorelin (3.75 mg, i.m. injection) every 28 days. The second group (24 girls) was treated with cyproterone acetate and triptorelin: cyproterone acetate (50 mg/m²) was administered every day for 8 weeks, and triptorelin (3.75 mg) was commenced 4 weeks after starting the cyproterone, then the intramuscular injection of triptorelin was repeated every 28 days.

Results:

Eight of 54 girls (15%) had mild withdrawal bleeding. There were no differences in incidence between groups 1 and 2. Girls with pubertal uterus at pelvic ultrasound had a higher incidence of uterine bleeding than girls with infantile uterus (25 vs. 7%), but this difference was not significant.

Conclusion:

Co-administration of cyproterone acetate and GnRH analogues does not significantly decrease the incidence of uterine bleeding.