Menarche downward trend, from more than 16 years in the mid-1800s to below 13 years by the 1980s, has been observed worldwide, irrespective of socioeconomic status, race or ethnicity

Trends in age at menarche in low- and middle-income countries. Tiziana Leone, Laura Brown. N-IUSSP, Mar 1 2021. https://www.niussp.org/article/trends-in-age-at-menarche-in-low-and-middle-income-countries-evolution-de-lage-a-la-menarche-dans-les-pays-a-revenu-faible-et-intermediaire/

Introduction

Menarche (first menstrual bleeding) serves as a critical marker of puberty, and the associated physiological and social changes that collectively symbolise sexual maturation, adulthood and fertility. From the adoption of adult behaviours and the beginning of sexual life to the shame and stigma which could lead to dropping out of school, the process and timing of puberty can have dramatic consequences in girls’ lives (Coast, Lattof and Strong 2019, Šaffa et al. 2019).

Average age at menarche has been recorded in some European countries and the United States since the mid-1800s. Evidence suggests a downward trend from more than 16 years in the mid-1800s to below 13 years by the 1980s (Euling et al. 2008). This trend has been observed worldwide, irrespective of socioeconomic status, race or ethnicity (Wronka 2010, Buttke, Sircar and Martin 2012). A study describing the mean age at menarche using World Fertility Survey (WFS) data from 1950 to 1980 in Sub-Saharan African countries showed that age at menarche was undergoing a transition similar to that of European countries in the nineteenth century and was generally linked to an improvement in young women’s nutrition and health (Garenne 2020).

Age at menarche is influenced by a unique set of genetic, socioeconomic, and environmental factors (Buttke, Sircar and Martin 2012). However, its implications on subsequent health outcomes are poorly understood. Much less is known about changes in the timing and determinants of age at menarche in low- and middle-income countries. Until recently, this has been due to a lack of suitable data.

Timing and determinants of the age at menarche are key to understanding the potential linkages with health outcomes later in life and also important because of the repercussions on sexual initiation and age at marriage, and consequently on fertility. Research in high-income countries shows that early menarche has been linked to an increased risk of several adverse reproductive health outcomes, including breast cancer, endometrial cancer, and miscarriage (Buttke, Sircar and Martin 2012). Early puberty has also been associated with mental health problems in middle adolescence, with the longer-term impact unknown (Coast, Lattof and Strong 2019). Eating disorders, lack of self-esteem and mental health problems in general are often associated with an early age at menarche. All these factors have implications for health at older ages.