US girls got their first periods increasingly earlier over the last 50 years, new study finds

Trend is especially pronounced among Black, Hispanic and Asian participants, and those who report lower socioeconomic status

Girls in the United States had their first periods earlier over the last five decades and it took longer to experience regular cycles, a new study has found.

The study, published in JAMA Network Open, found the trend is especially pronounced among Black, Hispanic, Asian and mixed race participants, and among those who reported lower socioeconomic status.