Age and seasonal factors in the incidence of premature sexual development in girls in the Jerusalem area.

We conducted a retrospective epidemiologic study on girls with signs of precocious sexual development followed-up in our clinic over a ten-year period. Of a total of 66 girls, 36 had premature thelarche, 11 had premature pubarche, and 19 had idiopathic complete precocious puberty. We noted a steady increase in the number of girls with premature sexual development over this period. Furthermore, the incidence of premature development of pubertal signs during spring months was significantly higher than in other seasons. Environmental influence on premature pubarche seems to be of lesser significance than on premature thelarche and complete precocious puberty.