Background: Currently, there are no studies on changes in the incidence of uterine rupture or maternal and foetal outcomes after uterine rupture during different birth policy periods in China. Moreover, the results of association studies of maternal age, parity and previous caesarean section number with the risk of maternal and foetal outcomes after uterine rupture have not been consistent. This research aims to conduct and discuss the above two aspects.
Methods: We included singleton pregnant women with no maternal complications other than uterine rupture from January 2012 to June 2019 in China’s National Maternal Near Miss Surveillance System. Through Poisson regression analysis with a robust variance estimator, we compared the incidences of uterine rupture and maternal and foetal outcomes after uterine rupture during different birth policy periods in China and determined the relationship between maternal age, parity or previous caesarean section number and uterine rupture or maternal and foetal outcomes after uterine rupture.
Results: This study included 8,637,723 pregnant women. The total incidences of uterine rupture were 0.13% (12,934) overall, 0.05% during the one-child policy, 0.12% during the partial two-child policy (aRR=1.96; 95% CI: 1.53-2.52) and 0.22% (aRR=2.89; 95% CI: 1.94 4.29) during the universal two-child policy. The maternal near miss and stillbirth rates after uterine rupture were respectively 2.35% (aRR=17.90; 95% CI: 11.81-27.13) and 2.12% (aRR=4.10; 95% CI: 3.19 5.26) overall, 5.46% and 8.18% during the first policy, 1.72% (aRR=0.60; 95% CI: 0.32-1.17) and 2.02% (aRR=0.57; 95% CI: 0.37-0.83) during the second policy, and 1.99% (aRR=0.90; 95% CI: 0.52-1.53) and 1.04% (aRR=0.36; 95% CI: 0.24-0.54) during the third policy. The risk of uterine rupture increased with parity and previous caesarean section number.
Conclusion: Our findings suggest that the total and different characteristics risk of uterine rupture in China increased and the risk of stillbirth after uterine rupture improved from the one-child policy period to the universal two-child policy period. The risk of uterine rupture increased with parity and previous caesarean section number. The higher the parity and lower the previous caesarean section number was, the more serious the maternal and foetal outcomes would be.