Dabrowski E, et al. - As per recent data, spontaneous thelarche (ST) occurs in 38% and spontaneous menarche (SM) occurs in 15%–16% among girls with Turner syndrome (TS), with those with mosaicism exhibiting higher rates. Evidence concerning rates of ST and SM in TS were sought via performing a systematic review of the literature. Further, rates were evaluated based on the type of chromosomal mosaicism. Searching MEDLINE via PubMed, Embase, and the Cochrane Database of Controlled Trials, researchers included studies reporting outcomes of ST and SM in girls with TS, diagnosed by genetic analysis. They assessed 2,699 patients in total for ST and 2,890 for SM from 43 articles. Overall the rates of ST were 32% and SM 20.8%. The lowest rates of ST (ie, 13%; 95% CI 8.7–19.7) and SM (ie, 9.1%; 95% CI 7.3–11.3) were noted for girls with X monosomy. The highest rates of ST (ie, 88.1%; 95% CI 62–97.1) and SM (ie, 66.2%; 95% CI 49.3–79.6) were reported in girls with 45,X/47,XXX. These findings suggest that karyotype in TS influences the rates of ST and SM. Hence the karyotype should strongly guide discussions concerning pubertal development and future reproductive potential when counseling patients.