Prediction of the Onset of Menarche from the Pubertal Growth Spurt of Height Using the Individual Growth Chart

Abstract

Background: We had investigated the correlation between menarche and pubertal growth spurt using a smoothing spline function in a preceding study to predict the onset of menarche and concluded that “subjects with an early start in the pubertal growth spurt have a relatively short period until menarche, while those with a late start in the pubertal growth spurt tend to have an extended period before menarche.” However, a prediction method using a smoothing spline function would be challenging as the analysis method for the general public.

Objective: We aimed at proposing a less complicated and more practical method for the prediction of the onset of menarche in schools using results of physical checkups.

Methods: The subjects were the same as those in the previous study: 320 female third-year high school students studying from 2012 to 2014 at a private combined junior high and high school in the Tokyo metropolitan area. We implemented two approaches for identifying the starting age of pubertal growth spurt. One was “visual observation method,” using data of 12 years of height data during physical checkups at school from the first grade to the third year in high school to obtain the target age from the growth chart. The other was the calculation approach applying “Matsumoto equation” implemented in the calculation of maximum increment age.

Results: We successfully identified the starting age of pubertal growth spurt of 99.1% subjects via the visual observation method and 83.1% subjects by applying the Matsumoto equation. As for the correlation between the starting age of pubertal growth spurt and menarche, we could confirm a high positive correlation （correlation coefficient, 0.735） via the visual observation method, while 0.134 by applying the Matsumoto equation. Thus, the visual observation method would be more suitable to identify the starting age of pubertal growth spurt in the viewpoint of enabling prediction of the onset of menarche in practice at schools. The average starting age of pubertal growth spurt was 9.6 years old. We divided the subjects into three groups according to their menarcheal age distribution to compare the differences in the starting age of pubertal growth spurt, which showed a similar trend with the results of the previous study. However, there was a slight significant difference among the three groups; it concentrated in the range of 2-3 years of difference.

Conclusion: To predict the menarcheal age in schools from the starting age of pubertal growth spurt, we should first identify the starting age of the subjects' pubertal growth spurt from their growth charts by visual observation and then predict that the subjects will experience menarche within the following 2-3 years. We should also consider that subjects with an early start of pubertal growth spurt tend to have a slightly shorter period before menarche than those with a late start of the pubertal growth spurt. We should note that there are some exception cases as well, such as small stature or early yet more prolonged pubertal growth spurt. Therefore, it is mandatory to follow each individual's growth by drawing growth charts.