OBJECTIVES: To explore the effects of one-child, selective two-child and universal two-child policy on cesarean section (CS) rates in China.

METHODS: Based on the Xiamen registry of pregnant women and offspring (REPRESENT), We collected the healthcare data of maternal and offspring from all maternity institutions among Xiamen City, a sub-provincial city in southeast China. According to the timing of different family planning policies announcement and the lagged time of taking effect (about nine months), the study period was divided into three stages, involving one-child (January 2009 to June 2014), selective-two (July 2014 to June 2016) and universal-two (July 2016 to March 2019). A modified Robson classification was further used to grade the individual’s risk of undergoing CS. Univariate and multivariable Poisson regression models were used to explore the effects of one-child, selective two-child and universal two-child policy on CS rates.

RESULTS: In total, 31.4% (165 951/528 118) of pregnant women underwent CS from 2009 to 2019. Over three stages (one-child, selective-two and universal-two), there were more pregnant women with delivery history (21.0%, 50.5 %, and 60.5%, p <0.001) and CS history (4.2%, 15.0% and 18.5%, p <0.001) . After adjusted the confounders, the multivariable Poisson models showed the risk of CS - compared with one-child stage - declined by 11% (adjusted relative risk 0.89, 95% confidential interval 0.88-0.90) in selective-two stage and 15% (0.85, 0.84-0.86) in universal-two stage. Similar results present in nulliparous population, with 12% drop in selective-two stage (0.88, 0.86-0.89) and 15% drop in universal-two stage (0.85, 0.84-0.86). Additionally, the risk of CS for multiparous women without CS history significantly decreased in selective-two stage (0.69, 0.66-0.73) and universal-two stage (0.56, 0.53-0.73).

CONCLUSIONS: The implementation of the two-child policies, both selective and universal, showed positive effect on the decline of CS rates in China.