Title: Spontaneous Pubertal Development in Turner’s Syndrome<sup>1</sup>
Abstract: The incidence of spontaneous puberty in Turner's syndrome is reported to be between 5–10% and, more recently in some series, as high as 20%. In an Italian retrospective multicenter study, of 522 patients older than 12 yr with Turner's syndrome, 84 patients (16, 1%) presented spontaneous pubertal development with menarche that occurred at a chronological age of 13.2 ± 1.5 yr (mean ± sd) and a bone age of 12.9 ± 1.9 yr. Karyotype distribution in the whole group was as follows: 52.1% (272 patients) X-monosomy (45,X), 13.2% (69 patients) mosaicism characterized by X-monosomy and cellular line with no structural abnormalities of the second X, 19.9% (104 patients) mosaicism characterized by X-monosomy and cellular line with structural abnormalities of the second X, and 14.8% (77 patients) structural abnormalities of the second X. Menstrual cycles were still regular in 30 patients at 9.2 ± 5.0 yr after menarche, 12 developed secondary amenorrhea 1.6 ± 2.0 yr after menarche, and 19 had irregular menstrual cycles 0.9 ± 1.8 yr after menarche. As signs of spontaneous puberty developed in 14.0% of X-monosomic patients and in 32.0% of patients with cell lines with more than one X, the presence of the second X seems to have a cardinal influence on the appearance of spontaneous puberty. Spontaneous pregnancy occurred in 3 patients (3.6%). The presence of chromosomal abnormalities and malformations in 2 of 3 pregnancies led us to agree with other investigators in discouraging unassisted pregnancies.