Early Term Birth in China and its Association with Universal Two-Child Birth Policy

Background: Early term births (ETB) are related to the morbidity and mortality of infants, and its incidences have not been reported in China. In this study, we aimed to describe the epidemiology of ETB at the national and provincial level, and explore its changes after the implementation of universal two-child policy owing to the timing of policy’s initiation across the research period.  Methods: This national multicenter cross-sectional study (n = 75132) used the China Labor and Delivery Survey data collected from 89 hospitals in 25 (out of 34) provinces of mainland China between March 1st 2015 and December 31st 2016. A total of 28,966 low-risk singleton live birth records were included in the analysis of association between universal two-child policy and ETB using a multi-level Poisson regression of sandwich estimation.  Findings: The weighted incidence of ETB was 30.1 per 100 all births (95% CI =30.06%, 30.14%) or 29.88 per 100 live births (95% CI = 29.97%, 30.05%) in China. The incidences of ETB were varied by maternal age, parity and previous uterine scars. We found that there were associations between universal two-child policy and ETB when not adjusting for (RR=1.19, p 0.05).  Interpretation: The incidence of ETB is high in China and demonstrated practice patterns amenable to improvement. Great importance should be attached to preventing ETB, which risk being more likely after the implementation of the universal two-child policy, especially in young women or women without previous uterine scars. Funding Statement: This study was partly supported by National Natural Science Foundation of China (81673179), the Science and Technology Commission of Shanghai Municipality (18140903100,19140903100), the Shenkang Hospital Development Center (SHDC12016239) Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was approved by the Ethics Committees of Xinhua Hosptial (XHECC2015-006) and World Health Organization(A65899). Since only anonymous clinical information were collected, no individual informed consent was obtained.