Study Reveals Earlier Menarche and Increased Irregularity in U.S. Girls

Research indicates significant shifts in menstrual health trends over the past five decades, especially among racial minorities and lower-income groups.

Average age of first menstruation has decreased from 12.5 years to 11.9 years since the 1950s.
Early menarche is linked to higher risks of cardiovascular disease, cancer, and other health issues.
The time to achieve menstrual cycle regularity has lengthened, with fewer girls reaching regular cycles within two years.
Childhood obesity, environmental factors, and stress are potential contributors to these trends.
Racial minorities and lower socioeconomic groups are disproportionately affected by these changes.