Puberty and Its Measurement: A Decade in Review

Journal of Adolescence, 2002

This paper has two main objectives. Firstly, to review the feasibility and validity of the various methods that have been used to measure puberty. With an appreciation of these measurement issues, the second objective is to summarize the evidence-base as to whether the age at menarche and the age at onset of puberty has decreased in recent years. In consideration of these methodologies, all of which report different levels of reliability and validity, it is only possible at present to draw inferences about possible changes in pubertal age and onset. Moreover, the wide variations in sample size, selection of participants (usually non-random), and study design reported in the reviewed studies have compounded this situation further. The paper closes by providing a summary of the findings which will be of relevance to those intending to critically review the current evidence surrounding age of puberty, as well as those set on carrying out future research into this area. r

Journal of Youth and Adolescence

There is inconsistency in the outcome measures of biological and psychosocial studies using measures of puberty as a predictor. For example, some studies show that maturational timing may have differential influences (positive, negative, or no effect) depending on the specific disorder, dimension of measure, and gender. Other studies have suggested that some effects may be more directly linked to pubertal stage or hormone concentrations rather than timing per se. This study outlines several conceptual and methodological issues that may be relevant to addressing these inconsistencies, in the context of examining data from a study of maturational hormones obtained from a unique longitudinal cohort of 24 girls (age 10.0 ± 1.6 years) and 36 boys (age 10.4 ± 1.6 years) in the early part of puberty, where the developmental trajectory of these hormones were tracked annually in 65% of the sample. We explored the contributions of measures of pubertal growth and sociodemographic factors on hormone concentrations. In brief, it appears that no single measure best captures the maturational processes during puberty and suggests that multiple processes are occurring in parallel. Several conceptual and methodological implications are discussed that may guide investigators in interpreting existing studies of pubertal timing and behavior as well as in conducting future studies.

Hormones and Behavior, 2013

Historical records reveal a secular trend toward earlier onset of puberty in both males and females, often attributed to improvements in nutrition and health status. The trend stabilized during the mid 20th century in many countries, but recent studies describe a recurrence of a decrease in age of pubertal onset. There appears to be an associated change in pubertal tempo in girls, such that girls who enter puberty earlier have a longer duration of puberty. Puberty is influenced by genetic factors but since these effects cannot change dramatically over the past century, environmental effects, including endocrine disrupting chemicals (EDCs), and perinatal conditions offer alternative etiologies. Observations that the secular trends in puberty in girls parallel the obesity epidemic provide another plausible explanation. Early puberty has implications for poor behavioral and psychosocial outcomes as well as health later in life. Irrespective of the underlying cause of the ongoing trend toward early puberty, experts in the field have debated whether these trends should lead clinicians to reconsider a lower age of normal puberty, or whether such a new definition will mask a pathologic etiology.

It is important to account for timing of puberty when studying the adolescent brain and cognition. The use of classical methods for assessing pubertal status may not be feasible in some studies, especially in male adolescents. Using data from a sample of 478 males from a longitudinal birth cohort, we describe the calculations of three independent height-based markers of pubertal timing: Age at Peak Height Velocity (APHV), Height Difference in Standard Deviations (HDSDS), and Percent Achieved of Adult Stature (PAAS). These markers correlate well with each other. In a separate cross-sectional study, we show that the PAAS marker correlates well with testosterone levels and self-reported pubertal-stage scores. We conclude by discussing key considerations for investigators when drawing upon these methods of assessing pubertal timing.

Child Development, 2009

Puberty is advanced by sex hormones, yet it is not clear how it is best measured. The interrelation of multiple indices of puberty was examined, including the Pubertal Development Scale (PDS), a picture-based interview about puberty (PBIP), and a physical exam. These physical pubertal measures were then associated with basal hormones responsible for advancing puberty. Participants included 160 early adolescents (82 boys). Puberty indices were highly correlated with each other. The physical exam stages correlated well with boys' and girls' testosterone and dehydroepiandrosterone and less so with girls' estradiol. The PDS and PBIP were similarly related to basal hormones. Self-report may be adequate when precise agreement is unnecessary. Multiple measures of puberty are viable options, each with respective strengths.

Journal of Adolescence, 2006

Purpose: To examine concordance between two self-reported measures of puberty: Sexual Maturation Scale (SMS) and Pubertal Development Scale (PDS) and their acceptability to adolescents. Methods: Participants of a school-based study in grades 5, 7 and 9 were classified into one of 5 pubertal stages using each method. Results: 2864 students (age 9-16 years) participated. Agreement was moderate for males (k 0.42, 95% CI 0.39, 0.45) and females (k 0.57, 95% CI 0.53, 0.61). Concordance within one stage was excellent (females 97%, males 89%), with discrepancies due to females being classified one stage later on the PDS (26%) and males one stage earlier (32%). There were more missing data for the SMS (13%) than the PDS (4%). (L. Bond).

Frontiers in Pediatrics, 2019

Puberty is a sensitive period of life characterized by the appearance of secondary sex characteristics which leads to a complete sexual maturation. It physiologically starts between the age of 8 and 13 years in girls and 9 and 14 years in boys. In the last two decades, several studies have showed that start of puberty has moved up to younger ages by 12-18 months, and some of the hypotheses trying to explain this change include the role of nutritional status and obesity and the influence of extrinsic factors such as exposure to endocrine-disrupting chemicals (EDCs), as well. The hypothalamic-hypophysis-gonadal axis develops during embryogenesis, and except for a period of activation immediately after birth, remains suppressed until the onset of pubertal development. At the beginning of puberty, the pulse generator is reactivated, probably due to progressive stimulatory influences on GnRH neurons from glial signals and neurotrasmitters. Kisspeptin and its receptor play a fundamental role in this phase. Premature Pubarche/Adrenarche, Premature Thelarche, and Premature Menarche are incomplete forms of precocious pubertal development that have their origin in endocrine mechanisms that only recently have started to be understood. It is important to distinguish these forms from the complete ones in order to reassure patients and parents about the non-evolution of pubertal progression and avoid non-useful treatments with analogous LHRH.

PEDIATRICS, 2014

BACKGROUND AND OBJECTIVES: Studies of adolescents often use self-assessment of pubertal maturation, the reliability of which has shown conflicting results. We aimed to examine the reliability of child and parent assessments of healthy boys and girls.

Journal of Adolescent Health, 2008

Puberty or pubertal timing can be a key variable in research, be it as a predictor or an outcome. Puberty is important in clinical practice as well. Although empirical studies with adolescents often do not include this variable, the literature has provided us with evidence of its importance for both research and practice. In this issue of the Journal, we are presented with an article that reports age at menarche has decreased across the last several generations . So, you ask, "What is new that we haven't already heard? What does the article have to offer?" Read on as we provide you with some interpretations and questions, as well as some food for thought about the next generation of studies. In brief, the study by Harris and colleagues also found a decrease in age at menarche, but the study design is different from many national databases that primarily used pubertal age or young adult participants. In their study, the authors drew from a national sample of over 8000 Canadian females age 15 and older. In a cross-sectional analysis of women whose date of birth ranged from before 1933 to those born as late as 1990, a secular trend in age at menarche was noted; specifically, age at menarche decreased by 8.8 months across the 5 or so decades observed in the study. This study provides complimentary findings similar to other studies showing this decline in age at menarche . The authors address the limitation of using a cross-sectional study, and briefly mention that a margin of error may be evident in reporting age at menarche both proximal and distal to the event. There is some concern that the authors have minimized the significance of this selfreport "error." That is, when the age span is so vast (e.g., women age 15 to >70 years) do we really know how much error there is in reporting? Further, there is at least one primary concern that was not raised by the authors. If one examines Figure , showing the relationship of age cohort to age at menarche, it appears that the relationship may be nonlinear . However, a linear model was used in the analysis. There is a curious "spike" in age at menarche in the 1964 to 1968 age cohort showing that age at menarche jumped to 13.4 years; up from about 12.8 years in the previous cohort. Similarly, in the 1969 to 1973 cohort that follows, age at menarche falls to 12.5 years, which is nearly a year earlier than the 1964 to 1968 cohort. Other rises and falls are noted across age cohorts, but none of this magnitude. It would be useful to determine if a nonlinear statistical model would provide a better fit to the data or if pair-wise comparisons noting significant differences would be appropriate in certain cases. Potentially, the outcome or interpretation of this study could change. Other issues of import include that outliers were not addressed in the article. Age at menarche ranged from 7 to 26 years, clearly illustrating that, at the minimum, some clinical abnormalities may exist in participants toward each of those extremes. Additionally, although race/ethnicity was controlled for in the analyses, it would have been helpful to know what the racial breakdown was because there is a literature on differences in timing of puberty by race . Would there be richer information if analyses were conducted separately? Harris and colleagues do go beyond just reporting that age at menarche is earlier. Their second aim focused on timing of menarche and its association with adult body mass index (BMI); that is, BMI at time of data collection, when females ranged in age from 15 to over 70 years of age.

Journal of Biology and Life Science, 2014

Puberty is a process that results from a coordinated series of complex neuroendocrine changes which eventually leads to external and internal physical changes. These changes include attainment of primary and secondary sexual characteristics. Puberty as a temporal process is subdivided into different stages. These pubertal stages occur in a sequential manner but significant variations have been seen among different individuals in the timings of pubertal onset as well as a certain degree of gender difference is also present where puberty is occurring 166 earlier in girls than boys. Among many aetiologies which have been hypothesized to be involved, environmental cues are the most ones. This review article describes the recent findings of the influences of the key environmental clues on pubertal timings, emphasizing on the aspects for which the most scientific evidences exist.