- 著者
-
阪本 州弘
大和田 国夫
庄司 博延
田中 平三
- 出版者
- The Japanese Society for Hygiene
- 雑誌
- 日本衛生学雑誌 (ISSN:00215082)
- 巻号頁・発行日
- vol.25, no.5, pp.446-452, 1970-12-30 (Released:2009-02-17)
- 参考文献数
- 6
A study was made on the relationship between birth order and menarche age of 1715 females students of high school and college in Osaka Prefecture in 1968. Results are as follows:1) The median of menarche age for birth order was 13 years and 1 month in the groups of one or two siblings with no relation of birth order. In 3 or over 4 sibling groups, however, the median of menarche age increased with an increase of birth order as follows; the median was 13 years, 13 years and 1 month, and 13 years and 4 months for the group of first, second and third birth order respectively.2) The distribution of the menarche age was analysed by the model in which was composed of 3 parameters of m, σ and λ; m was mean age in the complete stage of the preparation for menarche, σ was variance of the age and λ was the force of effect of external stimulation for menarche appearance.In a single sibling m was 12 years and 8 months, in two siblings group m was 12 years and 6 months, and 12 years and 10 months for first and second birth order respectively, therefore, the latter was 4 months later than the former. In the 3 siblings group, m became later with an increase of birth order as follows; 12 years and 7 months, 12 years and 6 months, 12 years and 9 months for the fiirst, second and third birth order respectively. λ was remarkably high in one sibling group and in the youngest for over two siblings groups.