Preterm birth rates have increased significantly worldwide over the past decade. Few epidemiological studies on the incidence of preterm birth and temporal trends are available in China. This study used national monitoring data from China's National Maternal Near Miss Surveillance System (NMNMSS) to estimate the rate of preterm birth and trends between 2012 and 2018 in China and to assess risk factors associated with preterm birth. In this observational study, data were sourced from the NMNMSS between Jan 1, 2012, and Dec 31, 2018. Pregnancies with at least one livebirth, with the baby born at 28 weeks of gestation or more or 1000 g or more birthweight were included. We estimated the rates of overall preterm, very preterm (born between 28 and 31 weeks' gestation), moderate preterm (born between 32 and 33 weeks' gestation), and late preterm (born between 34 and 36 weeks' gestation) births in singleton and multiple pregnancies and assessed their trends over time. We used logistic regression analysis to examine the associations between preterm birth and sociodemographic characteristics and obstetric complications, considering the sampling strategy and clustering of births within hospitals. Interrupted time series analysis was used to assess the changes in preterm birth rates during the period of the universal two child policy intervention. From Jan 1, 2012, to Dec 31, 2018, 9 645 646 women gave birth to at least one live baby, of whom 665 244 (6·1%) were born preterm. In all pregnancies, the overall preterm birth rate increased from 5·9% in 2012 to 6·4% in 2018 (8·8% increase; annual rate of increase [ARI] 1·3 [95% CI 0·6 to 2·1]). Late preterm births (8·8%; ARI 1·5% [0·9 to 2·2]) and very preterm births (13·3%; ARI 1·8% [0·5 to 3·0]) significantly increased from 2012 to 2018, whereas moderate preterm births did not (3·8%; ARI 0·3% [95% CI -0·9 to 1·5]). In singleton pregnancies, the overall preterm birth rate showed a small but significant 6·4% increase (ARI 1·0% [0·4 to 1·7]) over the 7 year period. In multiple pregnancies, the overall preterm birth rate significantly increased from 46·8% in 2012 to 52·7% in 2018 (12·4% increase; ARI 1·9% [1·2 to 2·6]). Compared with women who gave birth in 2012, those who gave birth in 2018 were more likely to be older (aged ≥35 years; 7·4% in 2012 vs 15·9% in 2018), have multiples (1·6% vs 1·9%), have seven or more antenatal visits (50·2% vs 70·7%), and have antepartum complications and medical disease (17·9% vs 35·1%), but they were less likely to deliver via caesarean section (47·5% vs 45·0%). Compared with the baseline period (January, 2012 to June, 2016), a higher increase in preterm birth was observed after the universal two child policy came into effect in July, 2016 (β=0·034; p=0·03). An increase in preterm births was noted for both singleton and multiple pregnancies between 2012 and 2018 in China. China's strategic investment in maternal and neonatal health has been crucial for the prevention of preterm birth. Due to rapid changes in sociodemographic and obstetric factors related to preterm birth-particularly within the context of the universal two child policy-such as advanced maternal age at delivery, maternal complications, and multiple pregnancies, greater efforts to reduce the burden of preterm birth are urgently needed. National Key R&D Program of China, National Health Commission of the People's Republic of China, China Medical Board, WHO, and UNICEF.

China has achieved Millennium Development Goal 4 to reduce under-5 mortality rate by two-thirds between 1990 and 2015. In this study, we estimated the national and subnational levels and causes of child mortality in China annually from 1996 to 2015 to draw implications for achievement of the SDGs for China and other low-income and middle-income countries. In this systematic analysis, we adjusted empirical data on levels and causes of child mortality collected in the China Maternal and Child Health Surveillance System to generate representative estimates at the national and subnational levels. In adjusting the data, we considered the sampling design and probability, applied smoothing techniques to produce stable trends, fitted livebirth and age-specific death estimates to natvional estimates produced by the UN for international comparison, and partitioned national estimates of infrequent causes produced by independent sources to the subnational level. Between 1996 and 2015, the under-5 mortality rate in China declined from 50·8 per 1000 livebirths to 10·7 per 1000 livebirths, at an average annual rate of reduction of 8·2%. However, 181 600 children still died before their fifth birthday, with 93 400 (51·5%) deaths occurring in neonates. Great inequity exists in child mortality across regions and in urban versus rural areas. The leading causes of under-5 mortality in 2015 were congenital abnormalities (35 700 deaths, 95% uncertainty range [UR] 28 400-45 200), preterm birth complications (30 900 deaths, 24 200-40 800), and injuries (26 600 deaths, 21 000-33 400). Pneumonia contributed to a higher proportion of deaths in the western region of China than in the eastern and central regions, and injury was a main cause of death in rural areas. Variations in cause-of-death composition by age were also examined. The contribution of preterm birth complications to mortality decreased after the neonatal period; congenital abnormalities remained an important cause of mortality throughout infancy, whereas the contribution of injuries to mortality increased after the first year of life. China has achieved a rapid reduction in child mortality in 1996-2015. The decline has been widespread across regions, urban and rural areas, age groups, and cause-of-death categories, but great disparities remain. The western region and rural areas and especially western rural areas should receive most attention in improving child survival through enhanced policy and programmes in the Sustainable Development Goals era. Continued investment is crucial in primary and secondary prevention of deaths due to congenital abnormalities, preterm birth complications, and injuries nationally, and of deaths due to pneumonia in western rural areas. The study also has implications for improving child survival and civil registration and vital statistics in other low-income and middle-income countries. Bill & Melinda Gates Foundation.

Objective To examine how the relaxation of the one child policy and policies to reduce caesarean section rates might have affected trends over time in caesarean section rates and perinatal and pregnancy related mortality in China. Design Observational study. Setting China’s National Maternal Near Miss Surveillance System (NMNMSS). Participants 6 838 582 births at 28 completed weeks or more of gestation or birth weight ≥1000 g in 438 hospitals in the NMNMSS between 2012 and 2016. Main outcome measures Obstetric risk was defined using a modified Robson classification. The main outcome measures were changes in parity and age distributions and relative frequency of each Robson group, crude and adjusted trends over time in caesarean section rates within each risk category (using Poisson regression with a robust variance estimator), and trends in perinatal and pregnancy related mortality over time. Results Caesarean section rates declined steadily between 2012 and 2016 (crude relative risk 0.91, 95% confidence interval 0.89 to 0.93), reaching an overall hospital based rate of 41.1% in 2016. The relaxation of the one child policy was associated with an increase in the proportion of multiparous births (from 34.1% in 2012 to 46.7% in 2016), and births in women with a uterine scar nearly doubled (from 9.8% to 17.7% of all births). Taking account of these changes, the decline in caesarean sections was amplified over time (adjusted relative risk 0.82, 95% confidence interval 0.81 to 0.84). Caesarean sections declined noticeably in nulliparous women (0.75, 0.73 to 0.77) but also declined in multiparous women without a uterine scar (0.65, 0.62 to 0.77). The decrease in caesarean section rates was most pronounced in hospitals with the highest rates in 2012, consistent with the government’s policy of targeting hospitals with the highest rates. Perinatal mortality declined from 10.1 to 7.2 per 1000 births over the same period (0.87, 0.83 to 0.91), and there was no change in pregnancy related mortality over time. Conclusions China is the only country that has succeeded in reverting the rising trends in caesarean sections. China’s success is remarkable given that the changes in obstetric risk associated with the relaxation of the one child policy would have led to an increase in the need for caesarean sections. China’s experience suggests that change is possible when strategies are comprehensive and deal with the system level factors that underpin overuse as well as the various incentives at work during a clinical encounter.

On 12 May, 2008, a devastating earthquake registering 8.0 on the Richter scale occurred in Sichuan Province, China, taking tens of thousands of lives and destroying the homes of millions of people. Many of the deceased were children, particular children less than five years old who were more vulnerable to such a huge disaster than the adult. In order to obtain information specifically relevant to further researches and future preventive measures, potential risk factors associated with earthquake-related child mortality need to be identified. We used four geographical detectors (risk detector, factor detector, ecological detector, and interaction detector) based on spatial variation analysis of some potential factors to assess their effects on the under-five mortality. It was found that three factors are responsible for child mortality: earthquake intensity, collapsed house, and slope. The study, despite some limitations, has important implications for both researchers and policy makers.