The aim of the study was to analyse growth and sexual development of untreated girls with puberty starting between 7 - 9 years. At the Endocrine Clinic of 2nd Department of Paediatrics, Faculty Hospital Motol-Prague, 19 girls were followed-up. Organic and/or other endocrine aetiology was excluded. Once a year, auxologial parameters, sexual development (Tanner stages), age at menarche, and menstrual cycle were evaluated. Initial bone age was advanced by 2.2 ± 1.3 yr (range 0 - 5). Nine girls with an initial height prediction (graphic method) 163.2 ± 4.6 cm and target height 164.6 ± 5.0 cm have had already achieved their final height 165.8 ± 6 cm (NS). Thirteen girls reached menarche at 11.5 ± 1.0 yr (9.6 - 13.6); i.e. 3.9 ± 1.2 yr (1.6 - 5.6) after the first signs of puberty. Menarche was earlier compared with their mothers (13.0 ± 1.1 yr) and with Czech standards (p < 0.05). The menstrual cycle was normal and regular in all girls with a postmenarchal period > 2 yr. Borderline and/or slowly progressing idiopathic early puberty should be considered a variant of normal development. Sexual development is normal and final height was not compromised. In such cases, therapy is not necessary.

        Key words: borderline and early puberty, untreated girls, growth, sexual development, final height