Association of interpregnancy interval and risk of adverse pregnancy outcomes in woman by different previous gestational ages.

BACKGROUND: With an increasing proportion of multiparas, proper interpregnancy intervals (IPIs) are urgently needed. However, the association between IPIs and adverse perinatal outcomes has always been debated. This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages. METHODS: We used individual data from China's National Maternal Near Miss Surveillance System between 2014 and 2019. Multivariable Poisson models with restricted cubic splines were used. Each adverse outcome was analyzed separately in the overall model and stratified models. The stratified models included different categories of fertility policy periods (2014-2015, 2016-2017, and 2018-2019) and infant gestational age in previous pregnancy (<28 weeks, 28-36 weeks, and ≥37 weeks). RESULTS: There were 781,731 pregnancies enrolled in this study. A short IPI (≤6 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.63 [1.55, 1.71] for vaginal delivery [VD] and 1.10 [1.03, 1.19] for cesarean section [CS]), low Apgar scores and small for gestational age (SGA), and a decreased risk of diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. A long IPI (≥60 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.18 [1.11, 1.26] for VD and 1.39 [1.32, 1.47] for CS), placenta previa, postpartum hemorrhage, diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes. The estimated risk of preterm birth, low Apgar scores, SGA, diabetes mellitus in pregnancy, and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss. CONCLUSION: For pregnant women with shorter or longer IPIs, more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.

Non-invasive prenatal testing for the detection of trisomies 21, 18, and 13 in pregnant women with various clinical indications: A multicenter observational study of 1,854,148 women in China.

OBJECTIVE: This study aimed to evaluate the performance of noninvasive prenatal testing (NIPT) for detecting three common trisomies (T21, T18, and T13) in pregnant women with diverse clinical indications. METHODS: Frequencies of NIPT, of high chance of having one of the three trisomies, and of confirmed trisomies were determined for women with each of seven clinical indications in a national cross-sectional survey of approximately 300 prenatal diagnosis centers. Data were collected for the period from October 1, 2016 to September 30, 2018 using the Prenatal Diagnosis Technology Management On-line Information System. The performance of NIPT for detecting the three trisomies in pregnant women with different clinical indications was assessed in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value, and the corresponding 95% confidence intervals. RESULTS: A total of 5766 true positive cases for T21, T18, and T13 were detected among 1,854,148 samples, giving an overall detection rate of 0.31% (95% CI: 0.30%-0.32%). Most positive cases were associated with "NT thickening" (1.18%) and "advanced maternal age" (0.51%). The detection sensitivities of NIPT were 99.60% for T21, 99.14% for T18, and 100% for T13, while the corresponding specificities were 99.90%, 99.94%, and 99.95%. The corresponding PPVs were 69.77%, 47.24%, and 22.36%. NIPT showed high sensitivity and specificity, regardless of clinical indication. In contrast, PPV for three trisomies varied widely between 9.09% and 66.46% depending on the clinical indication. Across seven clinical indications, PPV ranged from 50.62% to 73.09% for T21, 20.00%-58.33% for T18, and 4.17%-47.37% for T13. The highest PPVs were 73.09% for T21 in pregnancies involving "advanced maternal age", 58.33% for T18 in pregnancies with "NT thickening", and 47.37% for T13 in pregnancies with "NT thickening". CONCLUSIONS: NIPT shows high sensitivity and specificity for detecting T21, T18, and T13 in pregnant women with different clinical indications. However, PPV depends strongly on clinical indication, highlighting the need to strengthen education and genetic counseling about prenatal screening.

Characteristics and fetal outcomes of pregnant women with hypertensive disorders in China: a 9-year national hospital-based cohort study.

BACKGROUND: Hypertensive disorders of pregnancy (HDP) are a growing concern and a challenge for maternity care providers as the prevalence of hypertension continues to increase. However, optimal management of HDP is unclear. Therefore, we aimed to explore the differences in adverse fetal outcomes among women with different subtypes of HDP and different blood pressure (BP) levels, to provide evidence-based management of HDP. METHODS: We obtained data from China's National Maternal Near-Miss Surveillance System from 2012 to 2020. Associations between BP management and adverse fetal outcomes, stratified by the four subtypes of HDP, were assessed using logistic regression analysis with a robust variance estimator. RESULTS: For the period, a total of 393,353 pregnant women with HDP were included in the study; 8.51% had chronic hypertension, 2.27% had superimposed preeclampsia, 50.17% had preeclampsia or eclampsia, and 39.04% had gestational hypertension. The BP levels at delivery admission were mostly (61.14%) of non-severe stage 2 (systolic BP 140-159 mm Hg and/or diastolic BP 90-109 mm Hg) hypertension by American Heart Association classification. A high rate of adverse fetal outcomes was observed among women with HDP, especially among those aged < 20 or > 35 y or those diagnosed with superimposed preeclampsia. Compared with those with normal BP levels at delivery admission, we found an upward curve with increased risk among pregnant women with more severe BP levels, including the risk of preterm birth and small for gestational age (SGA) fetus. The odds ratios (ORs) of stillbirth, neonatal death, and low Apgar scores associated with severe stage 2 hypertension increased significantly. In addition, the association between BP at admission and fetal outcomes differed among women with varying HDP subtypes. Pregnant women with preeclampsia or eclampsia had an increased risk for preterm birth (adjusted OR [aOR], 1.33 [95% confidence interval {CI}, 1.07 ~ 1.65]) and SGA (aOR, 1.37 [95% CI, 1.10 ~ 1.71]) even when the admission BP was at stage 1 level. CONCLUSION: Greater attention should be paid to cases involving preeclampsia superimposed on chronic hypertension and pregnant women aged < 20 or > 35 y to mitigate the burden of adverse fetal outcomes caused by HDP.

Interrupted-time-series analysis of the immediate impact of COVID-19 mitigation measures on preterm birth in China.

Preliminary evidence from China and other countries has suggested that coronavirus disease 2019 (COVID-19) mitigation measures have caused a decline in preterm births, but evidence is conflicting. Utilising a national representative data of 11,714,947 pregnant women in China, we explored the immediate changes in preterm birth rates during the COVID-19 mitigation period using an interrupted-time-series analysis. We defined the period prior to February 1, 2020 as the baseline, followed by the COVID-19 mitigation stage. In the first month of the COVID-19 mitigation, a significant absolute decrease in preterm birth rates of 0.68% (95%CI:-1.10% to -0.26%) in singleton, and of 2.80% (95%CI:-4.51% to -1.09%) in multiple births was noted. This immediate decline in Wuhan was greater than that at the national level among singleton births [-2.21% (95%CI:-4.09% to -0.34% vs. -0.68%)]. Here we report an immediate impact of COVID-19 mitigation measures on preterm birth in China.

Temporal trends and adverse perinatal outcomes of twin pregnancies at differing gestational ages: an observational study from China between 2012-2020.

BACKGROUND: With the development of assisted reproductive technology, the twinning rate in China has been increasing. However, little is known about twinning from 2014 onwards. In addition, previous studies analysing optimal gestational times have rarely considered maternal health conditions. Therefore, whether maternal health conditions affect the optimal gestational time remains unclear. METHODS: Data of women delivered between January 2012 and December 2020 were collected through China's National Maternal Near Miss Surveillance System. Interrupted time series analysis was used to determine the rates of twinning, stillbirth, smaller than gestational age (SGA), and low Apgar scores (< 4) among twins in China. To estimate the risk of each adverse perinatal outcome for separate gestational weeks, a multivariate generalised linear model was used. Infants born at 37 weeks of gestational age or foetuses staying in utero were used as reference separately. The analyses were adjusted for the sampling distribution of the population and the cluster effect at the hospital and individual levels were considered. RESULTS: There were 442,268 infants enrolled in this study, and the adjusted rates for twinning, stillbirth, SGA, and low Apgar scores were 3.10%, 1.75%, 7.70%, and 0.79%, respectively. From 2012 to 2020, the twinning rate showed an increasing trend. Adverse perinatal outcomes, including stillbirth, SGA, and low Apgar scores showed a decreasing trend. A gestational age between 34 and 36 weeks decreased most for rate of stillbirth (average changing rate -9.72%, 95% confidence interval [CI] -11.41% to -8.00%); and a gestational age of between 37 and 38 weeks decreased most for rates of SGA (average changing rate -4.64%, 95% CI -5.42% to -3.85%) and low Apgar scores (average changing rate -17.61%, 95% CI -21.73% to -13.26%). No significant difference in changes in twinning rate or changes of each perinatal outcome was observed during periods of different fertility policies. Infants born at 37 weeks of gestation had a decreased risk of stillbirth, SGA, and low Apgar scores. Maternal antepartum or medical complications increased the risk of SGA and low Apgar scores in different gestational weeks. CONCLUSION: China's twinning rate showed an increasing trend, while adverse perinatal outcomes decreased from 2012 to 2020. Fertility policy changes have had little effect on the twinning rate or the rate of adverse perinatal outcomes such as stillbirth, SGA, or low Apgar scores. The optimal gestational age for twins was 37 weeks. Women pregnant with twins and with antepartum or medical complications should be cautious due to an increased risk of SGA and low Apgar scores.

Geographical disparities in infant mortality in the rural areas of China: a descriptive study, 2010-2018.

BACKGROUND: The infant mortality rate (IMR) is considered a basic measure of public health for countries around the world. The specific aim of our study was to provide an updated description of infant mortality rate among different regions in rural China, and assess the trends and causes of the IMR geographical disparities. METHODS: Data were collected from China's Under-5 Child Mortality Surveillance System(U5CMSS). The annual number of deaths and causes of death were adjusted using a 3-year moving average underreporting rate based on annual national data quality control results. The average annual decline rate (AADR) and the relative risk (RR) of the IMR and cause-specific infant mortality were calculated by Poisson regression and the Cochran-Mantel-Haenszel method. Data analysis was completed by SAS software. RESULTS: There was an apparent decrease in infant mortality in rural China from 2010 to 2018, at the AADR of 11.0% (95%CI 9.6-12.4), 11.2% (95%CI 10.3-12.1) and 6.6% (95%CI 6.0-7.3) in the eastern, central and western rural areas, respectively. The IMR was highest in the western rural area, followed by the central and eastern rural areas. Compared with the eastern rural area, the RR of infant mortality in the central rural area remained at 1.4-1.6 and increased from 2.4 (95%CI 2.3-2.6) in 2010-2012 to 3.1 (95% CI 2.9-3.4) in 2016-2018 in the western rural area. Pneumonia, preterm birth /LBW and birth asphyxia were the leading causes of infant deaths in the western rural area. Mortality rates of these three causes fell significantly in 2010-2018 but contributed to a higher proportion of deaths in the western rural area than in the central and western rural ares. CONCLUSIONS: Our study indicated that the infant mortality rate dropped significantly from 2010 to 2018, however, geographical disparities of IMR in rural China are still persist. Therefore, there is an urgent need for public health programmes and policy interventions for infants in western rural China.

Incidence, trends and risk factors for obstetric massive blood transfusion in China from 2012 to 2019: an observational study.

OBJECTIVES: This study aims to use the high-quality national monitoring data from the China's National Maternal Near Miss Surveillance System (NMNMSS) to ascertain the incidence, trends and risk factors of obstetric massive blood transfusion (MBT) from 2012 to 2019 in China and determine its clinical outcomes. SETTINGS: Observational study of hospitalised pregnancies who had given birth or ended their pregnancy among member hospitals of NMNMSS. PARTICIPANTS: 11 667 406 women were included in this study. PRIMARY AND SECONDARY OUTCOME MEASURES: We screened for the incidence, trends, risk factors and main reasons for obstetric MBT, and the outcomes after obstetric MBT. MBT was defined as the transfusion of ≥5 units of red blood cells or ≥1000 mL of whole blood. The incidence of MBT was defined as the MBT cases per 10 000 pregnancies. RESULTS: Obstetric MBT occurred in 27 626 cases, corresponding to an incidence of 23.68 per 10 000 maternities, which exhibited an increasing trend in China during 2012-2019 (14.03-29.59 per 10 000 maternities, p for trend <0.001). Obstetric MBT was mainly associated with amniotic fluid embolism, uterine atony, abnormal placenta, severe anaemia, ectopic pregnancy, abortion, caesarean section, advanced maternal age and multiparous from biological effect. While from sociological effects, uterine atony, severe anaemia and placenta previa are the top three complications which more likely to undergo obstetric MBT in the Chinese population. Overall, the secular trends of hysterectomy incidence (25.07%-9.92%) and MMR during hospitalisation (21.41‰-7.48‰) among women who underwent MBT showed decreasing trends (p for trend <0.001). CONCLUSION: To minimise the incidence of obstetric MBT, more attention should be paid to education on the importance of the antenatal visit, evidence-based transfusion practice and females who are multiparous and have an advanced age, amniotic fluid embolism, uterine atony, severe anaemia and placenta previa.

Preterm births in China between 2012 and 2018: an observational study of more than 9 million women.

BACKGROUND: 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. METHODS: 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. FINDINGS: 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 (ß=0·034; p=0·03). INTERPRETATION: 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. FUNDING: National Key R&D Program of China, National Health Commission of the People's Republic of China, China Medical Board, WHO, and UNICEF.

Characteristics and adverse outcomes of Chinese adolescent pregnancies between 2012 and 2019.

We aimed to describe the characteristics of adolescent pregnancy, determine its effect on adverse maternal and perinatal outcomes and explore whether that association varies with gestational age with the goal of proposing specific recommendations for adolescent health in China. This study included 2,366,559 women aged 10-24 years who had singleton pregnancies between 2012 and 2019 at 438 hospitals. Adolescent pregnancy was defined as younger than 20 years of age. We used multivariable logistic regression to estimate the effects. Women aged 20-24 years served as the reference group in all analyses. The proportion of rural girls with adolescent pregnancies rebounded after 2015 even though common-law marriage in rural areas decreased. Higher risks of eclampsia (adjusted odds ratio (aOR) 1.87, 95% confidence interval (CI) 1.57 ~ 2.23), severe anaemia (aOR 1.18, 95% CI 1.09 ~ 1.28), maternal near miss (MNM; aOR 1.24, 95% CI 1.12 ~ 1.37), and small for gestational age (SGA; aOR 1.30, 95% CI 1.28 ~ 1.33) were observed when gestational age was > 37 weeks. Adolescent pregnancy was independently associated with increased risks of other perinatal outcomes. Further implementation of pregnancy prevention strategies and improved health care interventions are needed to reduce adolescent pregnancies and prevent adverse fertility outcomes among adolescent women in China at a time when adolescent fertility rate is rebounding.

The trends and associated adverse maternal and perinatal outcomes of labour neuraxial analgesia among vaginal deliveries in China between 2012 and 2019: a real-world observational evidence.

BACKGROUND: There is a lack of national report of the labour neuraxial analgesia (NA) rates in China in recent years, especially after the national promotion policy. The adverse maternal and perinatal outcomes associated with NA in China are also unknown. The aim of this study is to estimate the trends of NA rates from 2012 to 2019, to evaluate the effect of national policy on promoting NA and to identify the association between NA and adverse outcomes in China. METHODS: We used the individual data from China's National Maternal Near Miss Surveillance System (NMNMSS) between 2012 and 2019, covering 438 hospitals from 326 urban districts or rural counties in 30 provinces across China. The analysis was restricted to singleton pregnant women who underwent vaginal delivery at or after 28 completed weeks of gestation. We estimate the trends of NA rates between 2012 and 2019, both at the national and provincial levels using Bayesian multilevel model. We also estimated the effect of the national pilot policy launched in 2018 using interrupted time-series analysis and identified the association between NA and adverse outcomes using modified Poisson regression combined with propensity score analysis. RESULTS: Over the study period, 620,851 of 6,023,046 women underwent vaginal delivery with NA. The estimated national NA rates increased from 8.4% in 2012 to 16.7% in 2019. Most provinces experienced the same rapid rise during this period. The national pilot policy accelerated the rise of the rates. No differences were observed between women with NA and without any analgesia in the incidence of uterine atony, placental retention, intrapartum stillbirths and 1- and 5-min Apgar scores lower than 7. However, women with NA had higher incidences of genital tract trauma (adjusted relative risk (aRR) 1.53, 95% confidence interval (CI) 1.04-2.26) and maternal near miss (aRR 1.35, 95% CI 1.08-1.69), only in hospitals which were not covered by the national pilot policy and usually lack of sufficient equipment and personnel. CONCLUSIONS: The national policy can effectively increase the NA rate. However, as genital tract trauma and maternal near miss may increase in low-resource hospitals, but not in high-resource hospitals, further study is required to identify the reasons.

Apgar score and neonatal mortality in China: an observational study from a national surveillance system.

BACKGROUND: To examine the association between the Apgar score and neonatal mortality over gestational age in China and to explore whether this association changed when Apgar scores were combined at 1 and 5 min. METHODS: Data for all singleton live births collected from 438 hospitals between 2012 and 2016 were used in this study. Poisson regression with a robust variance estimator adjusted for a complete set of confounders was used to describe the strength of the association between the Apgar score and neonatal mortality. RESULTS: The relative risks of neonatal death-associated intermediate Apgar score at 5 min peaked at 39-40 weeks of gestation and subsequently decreased if the gestational age increased to 42 weeks or above, in contrast to the low Apgar score. Among both preterm and term new-borns with Apgar scores at 5 min, new-borns that were not small for gestational age had a lower mortality rate than those that were small for gestational age. The association between Apgar score and the neonatal mortality was even stronger when scores at 1 and 5 min were combined. CONCLUSIONS: Apgar score is not only meaningful for preterm new-borns but also useful for term new-borns, especially term new-borns that are not small for gestational age. Once the baby's Apgar score worsens, timely intervention is needed. There is still a gap between China and high-income countries in terms of sustained treatment of new-borns with low Apgar scores.

Provincial-level outcomes of China's 'Reducing maternal mortality and eliminating neonatal tetanus' program.

To determine whether the nationwide program 'Reducing maternal mortality and eliminating neonatal tetanus' contributed to the rapid decline in China's maternal mortality ratio (MMR) and neonatal tetanus elimination by enhancing hospital delivery, we compared MMR and neonatal tetanus incidence rate (NTR) reductions by province from 2000 to 2013. The difference-in-difference method was used to analyze the program effect. Long-term effects were analyzed relative to MMR and NTR in 2000 and 2002, respectively, while short-term effects in a given year were analyzed relative to MMR and NTR in the preceding year. The national program was associated with a faster decline in MMR in the long term. The rate of decline showed an inverse 'U' shape from 2000 to 2013, peaking in 2009. The program had a short-term effect in MMR reduction in 2005, 2007, and 2009. The program was also associated with faster decline in NTR in the short term at some time points, but this association was not consistent and was not found in the long term. In conclusion, the program accelerated decline of MMR from 2000 to 2013 but did not clearly reduce NTR at the province level. Therefore, this targeted program worked efficiently in resource-poor areas.

Spatiotemporal trends and ecological determinants in maternal mortality ratios in 2,205 Chinese counties, 2010-2013: A Bayesian modelling analysis.

BACKGROUND: As one of its Millennium Development Goals (MDGs), China has achieved a dramatic reduction in the maternal mortality ratio (MMR), although a distinct spatial heterogeneity still persists. Evidence of the quantitative effects of determinants on MMR in China is limited. A better understanding of the spatiotemporal heterogeneity and quantifying determinants of the MMR would support evidence-based policymaking to sustainably reduce the MMR in China and other developing areas worldwide. METHODS AND FINDINGS: We used data on MMR collected by the National Maternal and Child Health Surveillance System (NMCHSS) at the county level in China from 2010 to 2013. We employed a Bayesian space-time model to investigate the spatiotemporal trends in the MMR from 2010 to 2013. We used Bayesian multivariable regression and GeoDetector models to address 3 main ecological determinants of the MMR, including per capita income (PCI), the proportion of pregnant women who delivered in hospitals (PPWDH), and the proportion of pregnant women who had at least 5 check-ups (PPWFC). Among the 2,205 counties, there were 925 (42.0%) hotspot counties, located mostly in China's western and southwestern regions, with a higher MMR, and 764 (34.6%) coldspot counties with a lower MMR than the national level. China's westernmost regions, including Tibet and western Xinjiang, experienced a weak downward trend over the study period. Nationwide, medical intervention was the major determinant of the change in MMR. The MMR decreased by 1.787 (95% confidence interval [CI]: 1.424-2.142, p < 0.001) per 100,000 live births when PPWDH increased by 1% and decreased by 0.623 (95% CI 0.436-0.798, p < 0.001) per 100,000 live births when PPWFC increased by 1%. The major determinants for the MMR in China's western and southwestern regions were PCI and PPWFC, while that in China's eastern and southern coastlands was PCI. The MMR in western and southwestern regions decreased nonsignificantly by 1.111 (95% CI -1.485-3.655, p = 0.20) per 100,000 live births when PCI in these regions increased by 1,000 Chinese Yuan and decreased by 1.686 (95% CI 1.275-2.090, p < 0.001) when PPWFC increased by 1%. Additionally, the western and southwestern regions showed the strongest interactive effects between different factors, in which the corresponding explanatory power of any 2 interacting factors reached up to greater than 80.0% (p < 0.001) for the MMR. Limitations of this study include a relatively short study period and lack of full coverage of eastern coastlands with especially low MMR. CONCLUSIONS: Although China has accomplished a 75% reduction in the MMR, spatial heterogeneity still exists. In this study, we have identified 925 (hotspot) high-risk counties, mostly located in western and southwestern regions, and among which 332 counties are experiencing a slower pace of decrease than the national downward trend. Nationally, medical intervention is the major determinant. The major determinants for the MMR in western and southwestern regions, which are developing areas, are PCI and PPWFC, while that in China's developed areas is PCI. The interactive influence of any two of the three factors, PCI, PPWDH, and PPWFC, in western and southwestern regions was up to and in excess of 80% (p < 0.001).

The national maternal near miss surveillance in China: A facility-based surveillance system covered 30 provinces.

To introduce the National Maternal Near Miss Surveillance System (NMNMSS) in detail and to report the composition of maternal near miss (MNM) in China.The NMNMSS was established by the National Health Commission at the end of 2010, covered over 400 health facilities from 30 provinces in China. The NMNMSS was designed to collect individual information for every pregnant woman admitted to obstetric department in the sampled health facilities. Cross tabulations and correlations were used to describe the distribution of population and sampled facilities in the NMNMSS, and to calculate the MNM mortality ratio for different complications and organ dysfunctions.The individual survey forms of 9,051,638 pregnant women were collected in the NMNMSS between 2012 and 2017. Compared with urban areas, there are very few well-quality medical resources in rural areas. Most women with pregnancy complications in rural areas can only be treated in Level 2 and lower hospitals. MNM in women with indirect obstetric complications received treatment more frequently in Level 3 hospital. The most common maternal complications in severe maternal outcomes (including maternal near miss and maternal death) are obstetrics hemorrhage (58.7%), hypertension disorder (28.0%), and severe anemia (20.6%). The overall MNM mortality ratio is 38:1. The MNM mortality ratios are lowest in amniotic fluid embolism, HIV/AIDS, heart disease, thrombophlebitis, and sepsis. For different organ dysfunctions, the ranks of the MNM mortality ratio from low to high are renal dysfunction, respiratory dysfunction, cardiovascular dysfunction, hepatic dysfunction, neurologic dysfunction, uterine dysfunction, coagulation dysfunction.The NMNMSS is a well-established hospital-based surveillance system for maternal complications in China. It can identify the maternal complications that need to improve health care immediately in China through a powerful longitudinal real-world evidence.

Prevalence of postterm births and associated maternal risk factors in China: data from over 6 million births at health facilities between 2012 and 2016.

Postterm births are associated with an increased risk of adverse perinatal outcomes, but few studies have investigated the epidemiological characteristics of postterm births. We aimed to estimate the prevalence of postterm births and examine the potential association between maternal sociodemographic and obstetric characteristics and postterm births. Data were collected from China's National Maternal Near Miss Surveillance System, 2012-2016. A logistic regression was used to assess the association between sociodemographic and obstetric characteristics and postterm births. A Poisson regression was used to determine the crude and adjusted trends of postterm births over time across regions. Among the 6,240,830 singleton births with gestational periods of 37 weeks or longer, 1.16% were postterm. The prevalence of postterm births was significantly higher in the western region and among mothers who delivered at a level ≤2 hospital, had a lower education, or were younger. A reduced risk of postterm births was observed among primiparous women, mothers who previously had a caesarean section, mothers with pregnancy complications, and mothers with ten or more antenatal visits. The risk of postterm births decreased as the number of antenatal visits increased. The overall postterm birth rates significantly decreased from 1.49% in 2012 to 0.70% in 2016. The postterm birth rates were markedly reduced in the east, central, and west regions, and the rate of the decrease was greater in the east than in the west. Furthermore, substantial decreases were observed across regions in 2014 and 2016. In conclusion, multiple sociodemographic and obstetric factors are associated with the prevalence of postterm births. A significant decreasing trend in postterm birth rates was observed in China.

Maternal mortality ratios in 2852 Chinese counties, 1996-2015, and achievement of Millennium Development Goal 5 in China: a subnational analysis of the Global Burden of Disease Study 2016.

BACKGROUND: As one of only a handful of countries that have achieved both Millennium Development Goals (MDGs) 4 and 5, China has substantially lowered maternal mortality in the past two decades. Little is known, however, about the levels and trends of maternal mortality at the county level in China. METHODS: Using a national registration system of maternal mortality at the county level, we estimated the maternal mortality ratios for 2852 counties in China between 1996 and 2015. We used a state-of-the-art Bayesian small-area estimation hierarchical model with latent Gaussian layers to account for space and time correlations among neighbouring counties. Estimates at the county level were then scaled to be consistent with country-level estimates of maternal mortality for China, which were separately estimated from multiple data sources. We also assessed maternal mortality ratios among ethnic minorities in China and computed Gini coefficients of inequality of maternal mortality ratios at the country and provincial levels. FINDINGS: China as a country has experienced fast decline in maternal mortality ratios, from 108·7 per 100 000 livebirths in 1996 to 21·8 per 100 000 livebirths in 2015, with an annualised rate of decline of 8·5% per year, which is much faster than the target pace in MDG 5. However, we found substantial heterogeneity in levels and trends at the county level. In 1996, the range of maternal mortality ratios by county was 16·8 per 100 000 livebirths in Shantou, Guangdong, to 3510·3 per 100 000 livebirths in Zanda County, Tibet. Almost all counties showed remarkable decline in maternal mortality ratios in the two decades regardless of those in 1996. The annualised rate of decline across counties from 1996 to 2015 ranges from 4·4% to 12·9%, and 2838 (99·5%) of the 2852 counties had achieved the MDG 5 pace of decline. Decline accelerated between 2005 and 2015 compared with between 1996 and 2005. In 2015, the lowest county-level maternal mortality ratio was 3·4 per 100 000 livebirths in Nanhu District, Zhejiang Province. The highest was still in Zanda County, Tibet, but the fall to 830·5 per 100 000 livebirths was only 76·3%. 26 ethnic groups had population majorities in at least one county in China, and all had achieved declines in maternal mortality ratios in line with the pace of MDG 5. Intercounty Gini coefficients for maternal mortality ratio have declined at the national level in China, indicating improved equality, whereas trends in inequality at the provincial level varied. INTERPRETATION: In the past two decades, maternal mortality ratios have reduced rapidly and universally across China at the county level. Fast improvement in maternal mortality ratios is possible even in less economically developed places with resource constraints. This finding has important implications for improving maternal mortality ratios in developing countries in the Sustainable Development Goal era. FUNDING: National Health and Family Planning Commission of the People's Republic of China, China Medical Board, WHO, University of Washington Center for Demography and Economics of Aging, Bill & Melinda Gates Foundation.

Prior caesarean section and likelihood of vaginal birth, 2012-2016, China.

OBJECTIVE: To examine the trends and safety of vaginal birth after caesarean section around the period of the one-child policy relaxation in China. METHODS: We used data from China's National Maternal Near Miss Surveillance System between 2012 and 2016. To examine trends in vaginal birth after caesarean section, we used Poisson regression with a robust variance estimator. We also assessed the association between vaginal birth after caesarean section and maternal and perinatal outcomes. FINDINGS: We analysed 871 636 deliveries by women with a previous caesarean section. Both in 2012 and 2016, the rate of vaginal birth after caesarean section was 9.8%. After adjusting for institutional, sociodemographic and obstetric characteristics, the rate increased by 14% between 2012 and 2016 (adjusted relative risk, aRR: 1.14; 95% confidence interval, CI: 1.07-1.21). Compared to women with a repeat caesarean section, women with a vaginal birth after caesarean section experienced lower incidence of uterine rupture (aRR: 0.26, 95% CI: 0.16-0.42), blood transfusion (aRR: 0.68, 95% CI: 0.53-0.87) and admission to the intensive care unit (aRR: 0.36, 95% CI: 0.25-0.52), but higher incidence of intrapartum stillbirths, (aRR: 7.20, 95% CI: 6.09-8.51), newborns with a 5-minute Apgar score less than 7 (aRR: 1.75, 95% CI: 1.54-1.99) and neonatal death before discharge (aRR: 1.90, 95% CI: 1.61-2.24). CONCLUSION: Promotion of vaginal birth after caesarean section could increase the rate even further in China. To ensure the safety of mothers and their newborns, national policies and guidelines on vaginal birth after caesarean section are needed.

Relaxation of the one child policy and trends in caesarean section rates and birth outcomes in China between 2012 and 2016: observational study of nearly seven million health facility births.

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.

Low birthweight in China: evidence from 441 health facilities between 2012 and 2014.

OBJECTIVE: This study aimed to identify new evidence about the burden and risk factors of low birthweight (LBW) in China using national facility-based data. METHODS: The association between sociodemographic and obstetric characteristics and LBW was examined using a multilevel model, taking into account the clustering of livebirths within hospitals and multiple gestations per woman. RESULTS: There were 3 915 965 deliveries and 235 247 cases born with LBW, producing a LBW rate of 5.36% in mainland China; 65.34% of all cases of LBW were caused by preterm birth. The LBW rate was particularly high for women who delivered at home, were younger than 14 years of age, were unmarried, were illiterate, had not received antenatal care, had delivered three or more infants and who had multiple gestations. Maternal complications were strongly associated with LBW, but the risk effects of full-term LBW were lower than for of LBW. CONCLUSIONS: China's LBW rate was lower than that of many other countries, but due to its large population size, the number of infants born with LBW still contributed significantly to the overall number of LBW births globally. By recognizing populations of the most disadvantaged women, we can identify opportunities for prevention and intervention that target LBW.

The Sex Ratio at Birth for 5,338,853 Deliveries in China from 2012 to 2015: A Facility-Based Study.

OBJECTIVE: The accuracy of a population-based sex ratio at birth (SRB) in China has long been questioned. To depict a more accurate profile, the present study used data from a national surveillance system for health facility births to explore the characteristics of SRB in China. METHODS: Data from China's National Maternal Near Miss Surveillance System between 2012 and 2015 were used. We restricted the analysis to live births of ≥28 completed gestational weeks or ≥1000 g birth weight. The strength of association between obstetric characteristics and SRB was examined using logistic regression, taking into account the sampling strategy and clustering of births within health facilities. RESULTS: There were 2,785,513 boys and 2,549,269 girls born alive between 2012 and 2015 in 441 health facilities. The SRB was 111.04 in 2012, 110.16 in 2013, 108.79 in 2014, and 109.53 in 2015. The SRB was high in the eastern region, especially in rural areas. The SRBs increased with mother's age and decreased with mother's education. The SRB in women who were pregnant for the first time was 104.30. The SRB in primipara was normal (104.35), but it was extremely high in non-primipara, especially for women with three or more parities (141.76); only 5.26% of live births fell within this group. The SRBs increased significantly by the number of parities, especially in the rural areas of the central region. After adjustment for sociodemographic factors, women with three or more parities were 1.39 (95% CI 1.34, 1.43) times more likely to give birth to a boy compared with primiparae who were pregnant for the first time. CONCLUSION: Our analysis suggests that the SRB was lower than what was reported officially but higher than normal. The government should keep strengthening supervision to prevent sex-selection, especially in the wake of the two-child policy implemented in 2015.