Women’s Health
Temporal trends in age at menarche among women in the United States from 1999 to 2018 Claire Cook* Claire Cook Hilary Brown Sonia Grandi Hailey Banack
Background: Early age at menarche (first menstrual period) is associated with an increased risk of cardiometabolic disease across the lifespan. Age at menarche may therefore represent a sentinel indicator for future chronic disease burden. The aim of this study is to describe the temporal trends in age at menarche from 1999 to 2018 using a nationally representative sample in the United States.
Methods: National Health and Nutrition Examination Survey (NHANES) data collected between 1999 and 2018 were used for this study. The study population included self-identified female participants who completed a retrospective Reproductive Health Questionnaire. Estimates of mean, standard deviation and median and interquartile range for age at menarche described in the total sample and according to age (at the time of the survey), period (NHANES data collection cycle), and cohort (birth cohort defined in 10-year intervals).
Results: Overall, mean age at menarche was 12.64y (± 1.68) among 31,138 women who completed the NHANES survey between 1999 and 2018. Mean age at menarche was highest in women over the age of 80 at the time of survey (13.02y ± 1.69) compared to 12.09y ± 1.03 in women 12-19y. Age at menarche decreased from 12.69y (± 1.65) in 1999-2001 to 12.56y (± 1.71) in 2017-2018. It also decreased by birth cohort, from 13.30y (± 1.69) among participants born in 1910-1919 to 11.79y (± 1.19) among participants born in 2000-2009 (Figure 1). Similar trends in age at menarche were seen based on birth cohort by period and age by period.
Conclusions: This study provides contemporary estimates on trends in age at menarche, highlighting decreasing temporal trends according to age, period, and birth cohort. These findings underscore the need for future research on the effect of age at menarche on women’s health outcomes across the lifecourse.
