Age at menarche in Canada: results from the National Longitudinal Survey of Children & Youth

Abstract

BackgroundGiven the downward trend in age at menarche and its implications for the reproductive health and wellbeing of women, little is known about menarcheal age in Canada. Most Canadian studies are only representative of specific populations. The present study, therefore, aims to assess the distribution of age at menarche for Canadian girls and explore its variation across socio-economic and demographic factors.MethodsThe analysis of the study was based on all female respondents aged 14 to 17 years during Cycle 4 (2000/2001) of the National Longitudinal Survey of Children & Youth (NLSCY). The main outcome was age at menarche assessed as the month and year of the occurrence of the first menstrual cycle. Kaplan Meier was used to estimate the mean and median of age at menarche. Chi-square test was used to assess the differences in early, average and later maturers across the different levels of socio-economic and demographic variables. Bootstrapping was performed to account for the complex sampling design.ResultsThe total number of girls analyzed in this study was 1,403 weighted to represent 601,911 Canadian girls. The estimated mean and median of age at menarche was 12.72 years (standard deviation = 1.05) and 12.67 years, respectively. The proportions of early (< 11.53 years), average (≥11.53 years and ≤13.91 years) and late maturers (> 13.91 years) were 14.6% (95% confidence interval (CI): 11.92-17.35), 68.0% (95% CI: 63.82-72.17) and 17.4% (95% CI: 14.10-20.63), respectively. Variations across the menarcheal groups were statistically significant for the province of residence, household income and family type.ConclusionThe findings of the study pave the way for future Canadian research. More studies are warranted to understand menarcheal age in terms of its variation across the provinces, the secular trend over time and its potential predictors.

Distúrbios menstruais entre mulheres de 15-54 anos de idade em Pelotas, Rio Grande do Sul, Brasil: estudo de base populacional

“…Quase metade da população apresentou pelo menos um sintoma menstrual no período de seis meses (46,4%;IC95%: 43,4), sendo tal prevalência superior à encontrada na literatura. Dados de duas revisões sistemáticas apontam uma prevalência em torno de 5 a 30% para distúrbios menstruais entre mulheres de outros países 27,28 .…”

“…Tais achados poderão auxiliar no planejamento de ações e serviços de saúde, especialmente os de atenção básica, que são a porta de entrada do maior contingente de mulheres que referiram a presença de distúrbios menstruais (menos escolarizadas, com maior paridade e fumantes) 21 (43,4). El sangrado menstrual excesivo fue el más prevalente (23,2%; 20,5-25,8), seguido por ciclo menstrual corto (19,2%; 16,6-21,8), durante los ciclos menstruales (14,8%; 12,7-16,9), hemorragia (11,1%; 9,1-13,2) y prolongada menstruación (7,9%; 6,3-9,4 …”

“…Para avaliar a prevalência de distúrbios menstruais e sua distribuição conforme paridade e características demográficas, sociais e comportamentais, entre 15- (43,4). O mais prevalente foi sangramento menstrual excessivo (23,2%; 20,5-25,8), seguido de ciclo menstrual curto (19,2%; 16,6-21,8), ciclo menstrual longo (14,8%; 12,7-16,9), sangramento intermenstrual (11,1%; 9,1-13,2) e menstruação prolongada (7,9%; 6,3-9,4 2,5,6,7 e quanto à duração da menstruação 8 , enquanto, para a variação regional da duração do ciclo menstrual, as evidências são mais fracas 9 .…”

Environmental Factors and Puberty Onset: An Update

“…Another studies found that girls with absent biological father from high SES exhibited precocious puberty than those having biological fathers in their homes. In the case of low income families, there is no link between early menarche and father absence (Deardroff et al, 2011;Belachew et al, 2011;James-Todd et al, 2010;Al-Sahab et al, 2010). The possible cause of precocious puberty may possibly be the familial stress due to maternal work load and diminution in maternal affection.…”

Intergenerational abortion tendency between mothers and teenage daughters: a population-based cohort study

“…We had 2 reasons for defining the exposure period as 4 years before to 12 years after the daughter's birth. First, given that the mean age at menarche is 12.7 years, 24 starting at 12 years after the daughter's birth would approximate the earliest age that a daughter might undergo induced abortion. Second, data on induced abortion were available in our data sets only from 1988 onward, the year when the procedure was legalized.…”