Article Text

Impact of Chinese one-child policy on sibling structure: experience from rural areas in three provinces
  1. Elina Hemminki1,
  2. Qian Long2,3,
  3. Zhuochun Wu4,
  4. Reija Klemetti1
  1. 1Department of Children, Young People and Families, National Institute for Health and Welfare, Helsinki, Finland
  2. 2Department of Maternal and Child Health, School of Public Health and Management School of Public Health, Chongqing Medical University, Chongqing, P.R. China
  3. 3Department of Public Health, University of Helsinki, Helsinki, Finland
  4. 4Department of Health Statistics and Social Medicine, School of Public Health, Fudan University, Shanghai, P.R. China
  1. Correspondence to Dr Elina Hemminki; elina.hemminki{at}


Objectives To study the influence of population policy and boy preference on the sibling structure, that is, in which order and combinations boys and girls are born into families.

Design A population-based survey with a representative sample of new mothers in 2008–2009 in rural China.

Setting Two provinces (Anhui and Shaanxi) where authorisation for a second child was usually given if the first birth was a daughter and one province (Chongqing) where only one child was authorised.

Participants The mothers giving birth in 2008–2009 were identified from family planning and hospital birth registers (including births outside hospitals) (n=5049). Of them, 3673 were interviewed by trained medical university staff members and students using structured questionnaire (response rate 73%).

Main outcome measures Children's distribution by sex and families' distribution by children's birth order and sex composition were calculated and compared with theoretical values based on the assumption that family planning policy is fully followed.

Results The recommended family policy was varyingly followed in the three provinces. In all provinces, there were more second children than allowed. If the policy allowing a second child only after a first-born girl were fully followed, it would result in a sibling structure in which the one-child family is always with a boy and in the two-child family the first one is always a girl. This sibling structure was partly seen in Anhui but weakly in Shaanxi. The policy allowing only one child would result in an equal number of boys and girls, but in Chongqing, there were more boys. In Anhui, unlike the other provinces, there were many more first-born girls than boys, which the authors could not fully explain.

Conclusion Population policy and boy preference influence the actual and relative number of girls and boys and also sibling structure.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: and

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Supplementary materials

  • Supplementary Data

    This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

    Files in this Data Supplement:


  • To cite: Hemminki E, Long Q, Wu Z, et al. Impact of Chinese one-child policy on sibling structure: experience from rural areas in three provinces. BMJ Open 2012;2:e001010. doi:10.1136/bmjopen-2012-001010

  • Contributors EH conceptualised the study and data analysis, interpreted findings and drafted the manuscript. QL conducted the analysis and participated in the interpretation of findings. ZW and RK participated in the conception and commented on the article. All authors have full access to data and read and approved the final manuscript.

  • Funding This study is part of the output of the CHIMACA project (015396) funded by the European Commission INCO Programme and coordinated by the National Institute for Health and Welfare, Helsinki. The researchers are independent from funder.

  • Competing interests None.

  • Ethics approval Ethics approval was approved by the International Centre for Reproductive Health, Ghent University (2008/143).

  • Provenance and peer review Not commissioned; externally peer reviewed.