 A recent study from Harvard School of Public Health has uncovered another strange twist to this finding. The earliest and most irregular periods happen among racial minority and low income families. This is a big deal because early menarche, someone's first menstrual period, can be a sign of future health issues. Joining me to help break this down is the study's lead author, Dr. Zifan Wang, postdoctoral research fellow at Harvard in Cambridge, Massachusetts.