Socio-demographic characteristics and outcomes of pregnant women who delivered prior to and after the termination of the one-child policy in China: a comparative study.

Background: The new Chinese fertility policy has recently received widespread public attention. However, there are few studies available on the comprehensive epidemiology of maternal and infant health with respect to the characteristic changes of childbearing women. In the study, we compared the maternal characteristics and pregnancy outcomes at different time points according to policy adjustments, accessed the possible relationship among these factors, and evaluated the impacts of these policies for medical and policy assistance.

Methods: This was a retrospective study. Data were collected from three representative hospitals in Zhejiang Province using stratified random sampling. The annual number of births, and maternal and child healthcare levels were the determining factors of sampling. Women who gave birth in November of 2012, 2014, and 2016 were recruited in accordance with the time of the change in the fertility policy, and we explored the differences in maternal socio-demographic characteristics, delivery mode and pregnancy outcomes.

Results: A total of 11,718 women were recruited, including 3480, 4044, and 4194 in November of 2012, 2014, and 2016, respectively. The proportions of multiparous women, women who aged ≥35 years, who received higher education, who had previous cesarean sections (CS), and who delivered in a high level hospital increased over time. In 2016, multipara accounted for 49.12, 14.47% were aged ≥35 years, nearly half of women had previous CS and delivered in a provincial hospital, 41.73% gave birth by CS, and 31.62% suffered pregnancy complications. The results of multiple logistic regression mode showed CS risk decreased significantly in 2014 (OR = 0.62; 95% CI, 0.55-0.67) relative to 2012, and risks of pregnancy complications (OR = 2.30; 95% CI, 1.86-2.83) and multiple births (OR = 3.25; 95% CI, 2.19-4.83) only increased in 2016 compared to 2012.

Conclusions: Some pregnancy outcomes increased as several key characteristics of childbearing women changed after China ended its "one-child" policy. This suggests that policy providers and medical staff need to strengthen healthcare in a consistent fashion regarding changes in birth policy.