The Impact of Severe Maternal Morbidity on Perinatal Outcomes in High Income Countries: Systematic Review and Meta-Analysis

Risk of Adverse Neonatal Events in Pregnancies Complicated by Severe Maternal Morbidity

OBJECTIVE

To investigate the risk of adverse neonatal events after a pregnancy complicated by severe maternal morbidity.

STUDY DESIGN

We analyzed a population-based cohort of deliveries in Quebec, Canada, from between 2006 and 2021. The main exposure measure was severe maternal morbidity comprising life-threatening conditions, such as severe hemorrhage, cardiac complications, and eclampsia. The outcome included adverse neonatal events, such as very preterm birth (gestational age <32 weeks), bronchopulmonary dysplasia, hypoxic ischemic encephalopathy, and neonatal death. Using log-binomial regression models, we estimated adjusted relative risks (RR) and 95% confidence intervals (CI) for the association between severe maternal morbidity and adverse neonatal events.

RESULTS

Among 1,199,112 deliveries, 29,992 (2.5%) were complicated by severe maternal morbidity and 83,367 (7.0%) had adverse neonatal events. Severe maternal morbidity was associated with 2.96 times the risk of adverse neonatal events compared with no morbidity (95% CI 2.90-3.03). Associations were greatest for mothers who required assisted ventilation (RR 5.86, 95% CI 5.34-6.44), experienced uterine rupture (RR 4.54, 95% CI 3.73-5.51), or had cardiac complications (RR 4.39, 95% CI 3.98-4.84). Severe maternal morbidity was associated with ≥3 times the risk of neonatal death and hypoxic-ischemic encephalopathy and ≥10 times the risk of very preterm birth and bronchopulmonary dysplasia.

CONCLUSIONS

Severe maternal morbidity is associated with an elevated risk of adverse neonatal events. Better prevention of severe maternal morbidity may help reduce burden of severe neonatal morbidity.

Measuring the impact of maternal critical care admission on short- and longer-term maternal and birth outcomes

PURPOSE

Factors increasing the risk of maternal critical illness are rising in prevalence in maternity populations. Studies of general critical care populations highlight that severe illness is associated with longer-term physical and psychological morbidity. We aimed to compare short- and longer-term outcomes between women who required critical care admission during pregnancy/puerperium and those who did not.

METHODS

This is a cohort study including all women delivering in Scottish hospitals between 01/01/2005 and 31/12/2018, using national healthcare databases. The primary exposure was intensive care unit (ICU) admission, while secondary exposures included high dependency unit admission. Outcomes included hospital readmission (1-year post-hospital discharge, 1-year mortality, psychiatric hospital admission, stillbirth, and neonatal critical care admission). Multivariable Cox and logistic regression were used to report hazard ratios (HR) and odds ratios (OR) of association between ICU admission and outcomes.

RESULTS

Of 762,918 deliveries, 1449 (0.18%) women were admitted to ICU, most commonly due to post-partum hemorrhage (225, 15.5%) followed by eclampsia/pre-eclampsia (133, 9.2%). Over-half (53.8%) required mechanical ventilation. One-year hospital readmission was more frequent in women admitted to ICU compared with non-ICU populations [24.5% (n = 299) vs 8.9% (n = 68,029)]. This association persisted after confounder adjustment (HR 1.93, 95% confidence interval [CI] 1.33, 2.81, p < 0.001). Furthermore, maternal ICU admission was associated with increased 1-year mortality (HR 40.06, 95% CI 24.04, 66.76, p < 0.001), stillbirth (OR 12.31, 95% CI 7.95,19.08, p < 0.001) and neonatal critical care admission (OR 6.99, 95% CI 5.64,8.67, p < 0.001) after confounder adjustment.

CONCLUSION

Critical care admission increases the risk of adverse short-term and long-term maternal, pregnancy and neonatal outcomes. Optimizing long-term post-partum care may benefit maternal critical illness survivors.

Trends in Apgar scores and umbilical artery pH: a population-based cohort study on 10,696,831 live births in Germany, 2008-2022

Low Apgar scores and low umbilical arterial (UA) blood pH are considered indicators of adverse perinatal events. This study investigated trends of these perinatal health indicators in Germany. Perinatal data on 10,696,831 in-hospital live births from 2008 to 2022 were obtained from quality assurance institutes. Joinpoint regression analysis was used to quantify trends of low Apgar score and UA pH. Additional analyses stratified by mode of delivery were performed on term singletons with cephalic presentation. Robustness against unmeasured confounding was analyzed using the E-value sensitivity analysis. The overall rates of 5-min Apgar scores < 7 and UA pH < 7.10 in liveborn infants were 1.17% and 1.98%, respectively. For low Apgar scores, joinpoint analysis revealed an increase from 2008 to 2011 (annual percent change (APC) 5.19; 95% CI 3.66-9.00) followed by a slower increase from 2011 to 2019 (APC 2.56; 95% CI 2.00-3.03) and a stabilization from 2019 onwards (APC - 0.64; 95% CI - 3.60 to 0.62). The rate of UA blood pH < 7.10 increased significantly between 2011 and 2017 (APC 5.90; 95% CI 5.15-7.42). For term singletons in cephalic presentation, the risk amplification of low Apgar scores was highest after instrumental delivery (risk ratio 1.623, 95% CI 1.509-1.745), whereas those born spontaneous had the highest increase in pH < 7.10 (risk ratio 1.648, 95% CI 1.615-1.682).          Conclusion: Rates of low 5-min Apgar scores and UA pH in liveborn infants increased from 2008 to 2022 in Germany. What is Known: • Low Apgar scores at 5 min after birth and umbilical arterial blood pH are associated with adverse perinatal outcomes. • Prospective collection of Apgar scores and arterial blood pH data allows for nationwide quality assurance. What is New: • The rates of liveborn infants with 5-min Apgar scores < 7 rose from 0.97 to 1.30% and that of umbilical arterial blood pH < 7.10 from 1.55 to 2.30% between 2008-2010 and 2020-2022. • In spontaneously born term singletons in cephalic presentation, the rate of metabolic acidosis with pH < 7.10 and BE < -5 mmol/L in umbilical arterial blood roughly doubled between the periods 2008-2010 and 2020-2022.

Neonatal outcomes according to different degrees of maternal morbidity: cross-sectional evidence from the Perinatal Information System (SIP) of the CLAP network

BACKGROUND

The burden of maternal morbidity in neonatal outcomes can vary with the adequacy of healthcare provision and tool implementation to improve monitoring. Such information is lacking in Latin American countries, where the decrease in severe maternal morbidity and maternal death remains challenging.

OBJECTIVES

To determine neonatal outcomes according to maternal characteristics, including different degrees of maternal morbidity in Latin American health facilities.

METHODS

This is a secondary cross-sectional analysis of the Perinatal Information System (SIP) database from eight health facilities in five Latin American and Caribbean countries. Participants were all women delivering from August 2018 to June 2021, excluding cases of abortion, multiple pregnancies and missing information on perinatal outcomes. As primary and secondary outcome measures, neonatal near miss and neonatal death were measured according to maternal/pregnancy characteristics and degrees of maternal morbidity. Estimated adjusted prevalence ratios (PRadj) with their respective 95% CIs were reported.

RESULTS

In total 85,863 live births were included, with 1,250 neonatal near miss (NNM) cases and 695 identified neonatal deaths. NNM and neonatal mortality ratios were 14.6 and 8.1 per 1,000 live births, respectively. Conditions independently associated with a NNM or neonatal death were the need for neonatal resuscitation (PRadj 16.73, 95% CI [13.29-21.05]), being single (PRadj 1.45, 95% CI [1.32-1.59]), maternal near miss or death (PRadj 1.64, 95% CI [1.14-2.37]), preeclampsia (PRadj 3.02, 95% CI [1.70-5.35]), eclampsia/HELPP (PRadj 1.50, 95% CI [1.16-1.94]), maternal age (years) (PRadj 1.01, 95% CI [<1.01-1.02]), major congenital anomalies (PRadj 3.21, 95% CI [1.43-7.23]), diabetes (PRadj 1.49, 95% CI [1.11-1.98]) and cardiac disease (PRadj 1.65, 95% CI [1.14-2.37]).

CONCLUSION

Maternal morbidity leads to worse neonatal outcomes, especially in women suffering maternal near miss or death. Based on SIP/PAHO database all these indicators may be helpful for routine situation monitoring in Latin America with the purpose of policy changes and improvement of maternal and neonatal health.

Risk factors for preterm birth: an umbrella review of meta-analyses of observational studies

BACKGROUND

Preterm birth defined as delivery before 37 gestational weeks is a leading cause of neonatal and infant morbidity and mortality. The aim of this study is to summarize the evidence from meta-analyses of observational studies on risk factors associated with PTB, evaluate whether there are indications of biases in this literature, and identify which of the previously reported associations are supported by robust evidence.

METHODS

We searched PubMed and Scopus until February 2021, in order to identify meta-analyses examining associations between risk factors and PTB. For each meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Evidence was graded as robust, highly suggestive, suggestive, and weak.

RESULTS

Eighty-five eligible meta-analyses were identified, which included 1480 primary studies providing data on 166 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections, and vaccines. Ninety-nine (59.3%) associations were significant at P < 0.05, while 41 (24.7%) were significant at P < 10-6. Ninety-one (54.8%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 37 (22.3%) and 12 (7.2%) associations, respectively. We evaluated all associations according to prespecified criteria. Seven risk factors provided robust evidence: amphetamine exposure, isolated single umbilical artery, maternal personality disorder, sleep-disordered breathing (SDB), prior induced termination of pregnancy with vacuum aspiration (I-TOP with VA), low gestational weight gain (GWG), and interpregnancy interval (IPI) following miscarriage < 6 months.

CONCLUSIONS

The results from the synthesis of observational studies suggest that seven risk factors for PTB are supported by robust evidence. Routine screening for sleep quality and mental health is currently lacking from prenatal visits and should be introduced. This assessment can promote the development and training of prediction models using robust risk factors that could improve risk stratification and guide cost-effective preventive strategies.

TRIAL REGISTRATION

PROSPERO 2021 CRD42021227296.

Risk factors for preterm labor: An Umbrella Review of meta-analyses of observational studies

Preterm birth defined as delivery before 37 gestational weeks, is a leading cause of neonatal and infant morbidity and mortality. Understanding its multifactorial nature may improve prediction, prevention and the clinical management. We performed an umbrella review to summarize the evidence from meta-analyses of observational studies on risks factors associated with PTB, evaluate whether there are indications of biases in this literature and identify which of the previously reported associations are supported by robust evidence. We included 1511 primary studies providing data on 170 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections and vaccines. Only seven risk factors provided robust evidence. The results from synthesis of observational studies suggests that sleep quality and mental health, risk factors with robust evidence should be routinely screened in clinical practice, should be tested in large randomized trial. Identification of risk factors with robust evidence will promote the development and training of prediction models that could improve public health, in a way that offers new perspectives in health professionals.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Societal cost of nine selected maternal morbidities in the United States

OBJECTIVE

To estimate the cost of maternal morbidity for all 2019 pregnancies and births in the United States.

METHODS

Using data from 2010 to 2020, we developed a cost analysis model that calculated the excess cases of outcomes attributed to nine maternal morbidity conditions with evidence of outcomes in the literature. We then modeled the associated medical and nonmedical costs of each outcome incurred by birthing people and their children in 2019, projected through five years postpartum.

RESULTS

We estimated that the total cost of nine maternal morbidity conditions for all pregnancies and births in 2019 was $32.3 billion from conception to five years postpartum, amounting to $8,624 in societal costs per birthing person.

CONCLUSION

We found only nine maternal morbidity conditions with sufficient supporting evidence of linkages to outcomes and costs. The lack of comprehensive data for other conditions suggests that maternal morbidity exacts a higher toll on society than we found.

POLICY IMPLICATIONS

Although this study likely provides lower bound cost estimates, it establishes the substantial adverse societal impact of maternal morbidity and suggests further opportunities to invest in maternal health.

A Systematic Review of Severe Maternal Morbidity in High-Income Countries

With declining maternal mortality rates in high-income countries (HICs), severe maternal morbidity (SMM) is becoming an important quality measure of maternal care. However, there is no international consensus on the definition and types of SMM. This study aims to critically analyze published literature on SMM in HICs. The objectives are to compare definitions and criteria used to identify SMM and identify the main causes and risk factors contributing to SMM in HICs. PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Scopus databases were searched for articles published between 2010 and 2022, results were filtered, and 10 studies were critically appraised. Six of the articles discussed SMM identification criteria and proposed definition modifications. Longer hospital stays and admission to the intensive care unit (ICU) were suggested as additional criteria. Disease-based criteria were shown to be superior to organ dysfunction criteria. Seven articles detailed common types of SMM as severe hemorrhage, hypertensive disorders, and preeclampsia/eclampsia. Six articles described SMM risk factors, of which advanced maternal age and cesarean delivery were the most common. This literature review identified disease-based criteria and Canadian study criteria as promising measures of SMM. It also identified several causes and risk factors of SMM common between HICs. These findings can help physicians identify women at risk of SMM. The study is however limited to eight HICs and 10 studies. Further research should aim to investigate how these criteria compare with previous sources of criteria and discern the association of weight and race risk factors with SMM.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

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 and perinatal outcomes of pregnant women with SARS-CoV-2 infection at the time of birth in England: national cohort study

BACKGROUND

Some studies have suggested that women with SARS-CoV-2 infection during pregnancy are at increased risk of adverse pregnancy and neonatal outcomes, but these associations are still not clear.

OBJECTIVE

This study aimed to determine the association between SARS-CoV-2 infection at the time of birth and maternal and perinatal outcomes.

STUDY DESIGN

This is a population-based cohort study in England. The inclusion criteria were women with a recorded singleton birth between May 29, 2020, and January 31, 2021, in a national database of hospital admissions. Maternal and perinatal outcomes were compared between pregnant women with a laboratory-confirmed SARS-CoV-2 infection recorded in the birth episode and those without. Study outcomes were fetal death at or beyond 24 weeks' gestation (stillbirth), preterm birth (<37 weeks' gestation), small for gestational age infant (small for gestational age; birthweight at the <tenth centile), preeclampsia or eclampsia, induction of labor, mode of birth, specialist neonatal care, composite neonatal adverse outcome indicator, maternal and neonatal length of hospital stay after birth (3 days or more), and 28-day neonatal and 42-day maternal hospital readmission. Adjusted odds ratios and their 95% confidence interval for the association between SARS-CoV-2 infection status and outcomes were calculated using logistic regression, adjusting for maternal age, ethnicity, parity, preexisting diabetes mellitus, preexisting hypertension, and socioeconomic deprivation measured using the Index of Multiple Deprivation 2019. Models were fitted with robust standard errors to account for hospital-level clustering. The analysis of the neonatal outcomes was repeated for those born at term (≥37 weeks' gestation) because preterm birth has been reported to be more common in pregnant women with SARS-CoV-2 infection.

RESULTS

The analysis included 342,080 women, of whom 3527 had laboratory-confirmed SARS-CoV-2 infection. Laboratory-confirmed SARS-CoV-2 infection was more common in women who were younger, of non-White ethnicity, primiparous, or residing in the most deprived areas or had comorbidities. Fetal death (adjusted odds ratio, 2.21; 95% confidence interval, 1.58-3.11; P<.001) and preterm birth (adjusted odds ratio, 2.17; 95% confidence interval, 1.96-2.42; P<.001) occurred more frequently in women with SARS-CoV-2 infection than those without. The risk of preeclampsia or eclampsia (adjusted odds ratio, 1.55; 95% confidence interval, 1.29-1.85; P<.001), birth by emergency cesarean delivery (adjusted odds ratio, 1.63; 95% confidence interval, 1.51-1.76; P<.001), and prolonged admission after birth (adjusted odds ratio, 1.57; 95% confidence interval, 1.44-1.72; P<.001) were significantly higher for women with SARS-CoV-2 infection than those without. There were no significant differences (P>.05) in the rate of other maternal outcomes. The risk of neonatal adverse outcome (adjusted odds ratio, 1.45; 95% confidence interval, 1.27-1.66; P<.001), need for specialist neonatal care (adjusted odds ratio, 1.24; 95% confidence interval, 1.02-1.51; P=.03), and prolonged neonatal admission after birth (adjusted odds ratio, 1.61; 95% confidence interval, 1.49-1.75; P<.001) were all significantly higher for infants with mothers with laboratory-confirmed SARS-CoV-2 infection. When the analysis was restricted to pregnancies delivered at term (≥37 weeks), there were no significant differences in neonatal adverse outcome (P=.78), need for specialist neonatal care after birth (P=.22), or neonatal readmission within 4 weeks of birth (P=.05). Neonates born at term to mothers with laboratory-confirmed SARS-CoV-2 infection were more likely to have prolonged admission after birth (21.1% compared with 14.6%; adjusted odds ratio, 1.61; 95% confidence interval, 1.49-1.75; P<.001).

CONCLUSION

SARS-CoV-2 infection at the time of birth is associated with higher rates of fetal death, preterm birth, preeclampsia, and emergency cesarean delivery. There were no additional adverse neonatal outcomes, other than those related to preterm delivery. Pregnant women should be counseled regarding risks of SARS-CoV-2 infection and should be considered a priority for vaccination.

Impact of ambient temperature exposure on newborns with low Apgar scores in northwest China

In the context of global climate change, research efforts were focused on the association of ambient temperatures on maternal and neonatal health condition, but few have examined associations with low Apgar scores. From January 1, 2017, to December 31, 2018, all singleton deliveries of Ningxia Hui Autonomous Region were extracted from the Hospital Information System (N = 182,322). Daily temperature data were obtained from the official website of China Meteorological Administration. Low Apgar scores were defined as Apgar score ≤ 3 at 5 min in the present study. Logistic regression models were used to estimate the adjusted association between prenatal temperature exposure and low Apgar scores. Restricted cubic spline models were used to explore the dose-response relationship between temperature and low Apgar scores. The study population included 182,322 live singleton births, with 1575 (0.86%) cases of low Apgar scores. The elevated ambient temperature in different exposure timing windows in late pregnancy was associated with increased risk of low Apgar scores. As compared to moderate (10th-90th) temperature exposure, prenatal exposure to extreme hot (>90th) was associated with 13.9-47.0% increased risk of low Apgar scores, while non-significant relationship was found between extreme cold (<10th) exposure and low Apgar scores. The restricted cubic spline models showed a U-shaped relationship between prenatal temperature exposure and low Apgar scores (P for non-linearity < 0.05). Exposure to high ambient temperature during late pregnancy is associated with an increased risk of low Apgar scores in northwest China.