Forgotten Diseases Research Foundation


Postnatal Growth

The files below contain growth curves for head size in Japanese children. The curves were made using data from a large national study performed in Japan in the early 1990s (1). Data was collected on ~27,000 children who were 0 to 18 years years old. An important advantage of the Japanese charts is that they provide head size information to the age of 18; most charts do not go beyond age 5. These charts may be useful for non-Japanese Asian teenagers and adults.

Head Circumference

Twins: Size at Birth by Gestational Age

The files in this section contain growth curves for size at birth in Japanese children. These kinds of curves are often called intrauterine growth curves, as they roughly reflect size in the womb (there is some debate about this point). The curves here were made using data from a study of 1,061 pairs of newborn twins (2,122 infants) who had been born in Japan between 1968 and 1990 (2). The authors measured the following:

  • Weight
  • Lengh
  • Head circumference
  • Chest circumference (not presented here)

The study showed that birthweight and birth length were lower in twins than in singleton births. Head and chest circumferences were the same in both groups. As a result, we have only included information on weight and length.

The curves below have been made directly from percentile data in the paper, without smoothing. Therefore, they may contain some features not typical of such curves, such as bumps and deflection at data points.

Weight at birth

Length at birth
Head Circumference
We have not included a chart for girls in this section. Unfortunately, the graphs that we created from the data in the paper were not usable.

Prader-Willi Syndrome

The file in this section contains numerous growth curves for PWS. The curves were published in the Appendix of the definitive book on managing Prader-Willi syndrome (3; has links to samples of each chapter). Growth curves for Japanese children with PWS begin on page 496 and go to page 503. They include the following:

  • Length, Boys and Girls, Birth to Age 2 years
  • Height, Boys and Girls, 2 to 18 Years
  • Weight, Boys and Girls, Birth to Age 2 years
  • Weight, Boys and Girls, 2 to 18 Years

  1. 1. Anzo M, Takahashi T et al. (2002) The cross-sectional head circumference growth curves for Japanese from birth to 18 years of age: the 1990 and 1992-1994 national survey data Ann Hum Biol 29(4):373-378. Abstract on PubMed.
  2. 2. Ooki S, Yokoyama Y. (2003) Reference birth weight, length, chest circumference, and head circumference by gestational age in Japanese twins. J Epidem 13(6):333-341. Full text from publisher.
  3. 3. Butler M et al (editors) (2006) Management of Prader-Willi Syndrome (3rd edition). USA, Prader-Willi Syndrome Association USA, Springer. Samples of four chapters on     Information about the book on    

Page last modified on 6 March 2021.