In a recent study published in JAMA Network Open , researchers examined the temporal trends and inequalities in menstruation onset, time to regularity, and the role of early-life body mass index (BMI) as a mediator. Menarche is the culmination of a sequence of reproductive processes, and early menarche can result in adverse health effects such as cardiovascular disease, cancer, spontaneous abortion, and premature mortality. Studies have documented trends toward early onset of menstruation in the United States (US); however, data on variances based on sociodemographic variables and BMI are scarce.
Most studies concentrate on the average age of menarche, with the frequency of early or late menarche rarely considered. The period from menstruation onset to regular menstrual cycles is an essential but seldom studied part of early-life menstrual health. Longer time to regularity is associated with poorer fertility, longer menstrual cycles, and an increased risk of metabolic disorders and all-cause mortality.
In the present study, researchers assessed temporal changes in menstruation onset and time taken for regular menstrual cycles in a racially and ethnically diverse sample group born between 1950 and 2005. They examined general temporal patterns and whether they differed by sociodemographic characteristics. They also investigated whether BMI at menarche would explain the observed temporal patterns.
The research included participants from the current Apple Women's Health research .
