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

Risk factors for maternal near-miss in an undeveloped province in south-central China, 2012-2022

OBJECTIVE

To explore the risk factors for maternal near-miss (MNM) using the WHO near-miss approach.

METHODS

Data were obtained from the Maternal Near-Miss Surveillance System in Hunan Province, China, 2012-2022. Multivariate logistic regression analysis (method: Forward, Wald, α = 0.05) and adjusted odds ratios (aORs) were used to identify risk factors for MNM.

RESULTS

Our study included 780,359 women with 731,185 live births, a total of 2461 (0.32%) MNMs, 777,846 (99.68%) non-MNMs, and 52 (0.006%) maternal deaths were identified. The MNM ratio was 3.37‰ (95%CI: 3.23-3.50). Coagulation/hematological dysfunction was the most common cause of MNM (75.66%). Results of multivariate logistic regression analysis showed risk factors for MNM: maternal age > = 30 years old (aOR > 1, P < 0.05), unmarried women (aOR = 2.21, 95%CI: 1.71-2.85), number of pregnancies > = 2 (aOR > 1, P < 0.05), nulliparity (aOR = 1.51, 95%CI: 1.32-1.72) or parity > = 3 (aOR = 1.95, 95%CI: 1.50-2.55), prenatal examinations < 5 times (aOR = 1.13, 95%CI: 1.01-1.27), and number of cesarean sections was 1 (aOR = 1.83, 95%CI: 1.64-2.04) or > = 2 (aOR = 2.48, 95%CI: 1.99-3.09).

CONCLUSION

The MNM ratio was relatively low in Hunan Province. Advanced maternal age, unmarried status, a high number of pregnancies, nulliparity or high parity, a low number of prenatal examinations, and cesarean sections were risk factors for MNM. Our study is essential for improving the quality of maternal health care and preventing MNM.

Severe acute maternal morbidity reporting in Australia: Why is it so hard?

Adverse outcomes associated with pregnancy, including severe acute maternal morbidity (SAMM) and mortality, are internationally regarded as important indicators of quality of maternity services. Varied definitions and processes are barriers for SAMM recording, reporting and review. Identifying and documenting these cases of SAMM is a critical first step. Case reviews allow exploration of factors contributing to SAMM. Translation of the lessons learnt into practice improvement strategies and dissemination of this knowledge is essential for continual quality improvement. This review will outline the current status of SAMM review internationally and in Australia.

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.

Dose-response associations of maternal age with pregnancy complications and multimorbidity among nulliparas and multiparas: A multicentric retrospective cohort study in southern China

Background

Advanced maternal age is becoming an increasingly common issue worldwide, presenting substantial health risks to pregnant women. However, dose-response associations of maternal age with a comprehensive range of pregnancy complications and their multimorbidity remain unclear.

Methods

We conducted a retrospective cohort study using data from China's National Maternal Near Miss Surveillance System for 2017-2018, including 18 hospitals in southern China. We included 135 274 pregnant women aged 15-54 years with a singleton birth. We used multivariable logistic regression and restricted cubic spline to examine dose-response associations between maternal age and various pregnancy complications, as well as multimorbidity. We employed the Apriori algorithm to mine the association rules among pregnancy complications and identify frequent multimorbidity patterns.

Results

We found three distinct patterns of associations between maternal age and specific pregnancy complications. In relation to increasing maternal age, gestational diabetes mellitus, preeclampsia, and gestational hypertension showed nonlinear increasing trends for both nulliparas and multiparas, as did multimorbidity in nulliparas. Conversely, we observed linear increasing trends for placental previa in both nulliparas and multiparas, placental abruption in nulliparas, and multimorbidity in multiparas. Infection and severe anaemia had an approximate J-shaped curve among nulliparas, while postpartum haemorrhage exhibited a similar curve in both nulliparas and multiparas. Advanced maternal age was linked to an elevated risk of multimorbidity during pregnancy or postpartum period, exhibiting more complicated patterns. The most common multimorbidity patterns in this age group were "preeclampsia + gestational diabetes mellitus", "gestational hypertension + gestational diabetes mellitus", "infection + gestational diabetes mellitus", and "placental previa + gestational diabetes mellitus".

Conclusions

Maternal age was associated with pregnancy complications and multimorbidity in three broad dose-response manners, including approximate J-shaped curves, as well as nonlinear and linear increasing trends, depending on the specific outcome and parity, which may suggest different underlying biological mechanisms. Women with advanced maternal age had a higher risk and more complicated patterns of multimorbidity during pregnancy or postpartum, suggesting that this group should be targeted for more intensive health care.

Association of Daytime-Only, Nighttime-Only, and Compound Heat Waves With Preterm Birth by Urban-Rural Area and Regional Socioeconomic Status in China

Importance

Associations between heat waves and preterm birth (PTB) have been reported. However, associations of daytime-only, nighttime-only, and compound heat waves with PTB have yet to be explored at a national level. Furthermore, possible heterogeneity across urban-rural communities with different socioeconomic statuses needs to be explored.

Objective

To examine the association between daytime-only, nighttime-only, and compound heat waves and PTB in China and to find variations between urban and rural regions.

Design, Setting, and Participants

This case-crossover study used nationwide representative birth data between January 1, 2012, and December 31, 2019, from China's National Maternal Near Miss Surveillance System. This multisite study covered 30 provinces in China and ensured the representation of urban and rural populations across 3 socioeconomic regions. Singleton live births delivered in the warm seasons from April to October during the study period were included. Exclusion criteria consisted of gestational age younger than 20 or older than 45 weeks, maternal ages younger than 13 or older than 50 years, conception dates earlier than 20 weeks before January 1, 2012, and later than 45 weeks before December 31, 2019, and an inconsistent combination of birthweight and gestational age according to growth standard curves of Chinese newborns. Data were analyzed from September 10, 2021, to April 25, 2023.

Exposures

Eighteen definitions of heat waves by 3 distinct types, including daytime only (only daily maximum temperature exceeds thresholds), nighttime only (only daily minimum temperature exceeds thresholds), and compound (both daily maximum and minimum temperature exceeds thresholds) heat waves, and 6 indexes, including 75th percentile of daily temperature thresholds for 2 or more (75th-D2), 3 or more (75th-D3), or 4 or more (75th-D4) consecutive days and 90th percentile of daily temperature thresholds for 2 or more (90th-D2), 3 or more (90th-D3), and 4 or more (90th-D4) consecutive days.

Main Outcomes and Measures

Preterm births with less than 37 completed weeks of gestation.

Results

Among the 5 446 088 singleton births in the final analytic sample (maternal mean [SD] age, 28.8 [4.8] years), 310 384 were PTBs (maternal mean [SD] age, 29.5 [5.5] years). Compared with unexposed women, exposure of pregnant women to compound heat waves in the last week before delivery was associated with higher risk for PTB, with the adjusted odds ratios (AORs) ranging from 1.02 (95% CI, 1.00-1.03) to 1.04 (95% CI, 1.01-1.07) in 6 indexes. For daytime-only heat wave exposures, AORs ranged from 1.03 (95% CI, 1.01-1.05) to 1.04 (95% CI, 1.01-1.08) in the 75th-D4, 90th-D2, 90th-D3, and 90th-D4 indexes. Such associations varied by rural (AOR range, 1.05 [95% CI, 1.01-1.09] to 1.09 [95% CI, 1.04-1.14]) and urban (AOR range, 1.00 [95% CI, 0.98-1.02] to 1.01 [95% CI, 0.99-1.04]) regions during exposure to daytime-only heat waves in the 75th-D3 and 90th-D3 indexes.

Conclusions and Relevance

In this case-crossover study, exposure to compound and daytime-only heat waves in the last week before delivery were associated with PTB, particularly for pregnant women in rural regions exposed to daytime-only heat waves. These findings suggest that tailored urban-rural preventive measures may improve maternal health in the context of climate change.

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.

A scoping review of maternal near miss assessment in Australia, New Zealand, South-East Asia and the South Pacific region: How, what, why and where to?

BACKGROUND

Severe maternal morbidity or maternal near miss (MNM) events can have significant consequences for individuals, their families and society and the study of these events may inform practices to reduce future adverse pregnancy outcomes.

AIMS

To review the scope of MNM studies undertaken in Australia, New Zealand, South-East Asia and the South Pacific region.

MATERIALS AND METHODS

A systematic search of four online databases (MEDLINE, EMBASE, SCOPUS and CINAHL) and the World Health Organization Library was conducted to identify all relevant studies published between 1 January 2011 and 31 December 2020. The studies were reviewed and included if they assessed MNM using a composite outcome or a predefined set of indicators.

RESULTS

The literature search yielded 143 articles of which 49 are included in this review. There were substantial differences in the monitoring approach to MNM in the Australasian region. Overall rates of MNM in the region ranged from two to 100/1000 births and the most common aetiologies identified were direct obstetric causes such as postpartum haemorrhage, pre-eclampsia and sepsis. Multidisciplinary review indicated a substantial number of MNM cases were preventable or amenable to improved management, mostly from a provider perspective.

CONCLUSIONS

Assessment of MNM is an important part of the evaluation of maternity care provision. Reaching a consensus on indicators and how best to collect information will allow a more discerning assessment of MNM including longer-term health outcomes, aspects of preventability and financial implications for health services.

Maternal mortality: near-miss events in middle-income countries, a systematic review

OBJECTIVE

To describe the incidence and main causes of maternal near-miss events in middle-income countries using the World Health Organization's (WHO) maternal near-miss tool and to evaluate its applicability in these settings.

METHODS

We did a systematic review of studies on maternal near misses in middle-income countries published over 2009-2020. We extracted data on number of live births, number of maternal near misses, major causes of maternal near miss and most frequent organ dysfunction. We extracted, or calculated, the maternal near-miss ratio, maternal mortality ratio and mortality index. We also noted descriptions of researchers' experiences and modifications of the WHO tool for local use.

FINDINGS

We included 69 studies from 26 countries (12 lower-middle- and 14 upper-middle-income countries). Studies reported a total of 50 552 maternal near misses out of 10 450 482 live births. Median number of cases of maternal near miss per 1000 live births was 15.9 (interquartile range, IQR: 8.9-34.7) in lower-middle- and 7.8 (IQR: 5.0-9.6) in upper-middle-income countries, with considerable variation between and within countries. The most frequent causes of near miss were obstetric haemorrhage in 19/40 studies in lower-middle-income countries and hypertensive disorders in 15/29 studies in upper-middle-income countries. Around half the studies recommended adaptations to the laboratory and management criteria to avoid underestimation of cases of near miss, as well as clearer guidance to avoid different interpretations of the tool.

CONCLUSION

In several countries, adaptations of the WHO near-miss tool to the local context were suggested, possibly hampering international comparisons, but facilitating locally relevant audits to learn lessons.

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.

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.