Fig. 1
From: How does the two-child policy affect the sex ratio at birth in China? A cross-sectional study
The trend of SRB at three stages of Two-Child Policy (22 hospitals in Hebei Province of China, 2013–2017). a The gross SRB at three stages; b The SRB in maternal age subgroups at three stages; c The SRB in delivery mode subgroups at three stages; d The SRB in parity subgroups at three stages; e The SRB in maternal education subgroups at three stages; f The SRB in urban or rural hospital at three stages. BTCP: Both the husband and wife of one couple were the only child of their parents, the couple were allowed to have Two Children in Policy (January 1, 2013 - May 29, 2014); OTCP: only the husband or wife of one couple was the only child of their parents, the couple were allowed to have Two Children in Policy (May 30, 2014 - December 31, 2015); UTCP: the Universal Two-Child Policy, every couple were allowed to have two children (January 1, 2016 - December 31, 2017). SRB: Sex Ratio at Birth