Severe maternal morbidity in Scotland

Predicting risk of maternal critical care admission in Scotland: Development of a risk prediction model

Background

Identifying women at highest or lowest risk of perinatal intensive care unit (ICU) admission may enable clinicians to risk stratify women antenatally so that enhanced care or elective admission to ICU may be considered or excluded in birthing plans. We aimed to develop a statistical model to predict the risk of maternal ICU admission.

Methods

We studied 762,918 pregnancies between 2005 and 2018. Predictive models were constructed using multivariable logistic regression. The primary outcome was ICU admission. Additional analyses were performed to allow inclusion of delivery-related factors. Predictors were selected following expert consultation and reviewing literature, resulting in 13 variables being included in the primary analysis: demographics, prior health status, obstetric history and pregnancy-related factors. A complete case analysis was performed. K-fold cross validation was used to mitigate against overfitting.

Results

Complete data were available for 578,310 pregnancies, of whom 1087 were admitted to ICU (0.19%). Model performance was fair (area under the ROC curve = 0.66). A comparatively high cut-point of ⩾0.6% for ICU admission risk resulted in a negative predictive value (NPV) of 99.8% (specificity 97.8%) but positive predictive value (PPV) of 0.8% (sensitivity 9.1%). Models including delivery-related factors demonstrated superior discriminative performance.

Conclusions

Our model for maternal ICU admission has an acceptable discriminative performance. The low frequency of ICU admission and resulting low PPV indicates that the model would be unlikely to be useful as a 'rule-in' test for pre-emptive consideration of ICU admission. Its potential for improving efficiency in screening as a 'rule-out' test remains uncertain.

Severe maternal morbidity in the high income setting: a systematic review of composite definitions

Background

Severe maternal morbidity (SMM) is an important indicator for the improvement of maternity care. Measurement of SMM varies, limiting global comparisons. To promote concordance we studied how SMM has been defined in epidemiological practice.

Methods

Comprehensive composite definitions of SMM in pregnancy or up to 6 weeks postnatal that captured both obstetric and non-obstetric processes in high-income settings were identified through a prospectively registered (PROSPERO CRD42023421377) systematic search of PubMed, Embase, and Google Scholar 01/01/1993-31/08/2024. Clinical concepts, diagnostic and procedural codes captured by definitions of SMM were compared and the variation between definitions was described.

Findings

The initial search identified 7852 records and 40 studies were included: 28 studies that reported 32 definitions of SMM for use with administrative data, with median incidence of 11.4/1000, and 13 studies that reported 13 definitions for use with the primary medical record, with median SMM incidence of 6.7/1000. The majority of definitions included cardiac, respiratory, and renal dysfunction or failure; haemorrhagic, thrombotic or infective morbidity; and critical interventions. Up to 75% of cases of SMM under some definitions involved transfusion. The main source of variation between definitions was the selection and definition of common obstetric diagnoses. Variation in the sources of additional routine data required to construct a definition also limited comparability.

Interpretation

Despite common approaches to defining SMM, there are opportunities to improve comparability. No two definitions for use with administrative data in different settings involved a similar incidence and set of components and involved a similar distribution of components among cases. Harmonization of the purpose, constituent codes, and sources of data would facilitate comparisons between maternity systems.

Funding

This work was supported by the Medical Research Council [MR/X006115/1] as well as the National Institute for Health Research [NIHR204430].

Prevalence, underlying causes, and determinants of maternal near miss in Ethiopia: a systematic review and meta-analysis

Background

Maternal near miss (MNM) is one of the newly adopted assessment parameters to gauge the quality of maternity care. In Ethiopia, several studies have been conducted to investigate the incidence, underlying causes, and determinants of MNM. However, the findings from those studies vary greatly and are largely inconsistent. Thus, this review aims to more robustly estimate the pooled prevalence, identify underlying causes, and single out determinants of MNM in Ethiopia.

Methods

Studies were searched from international databases (PubMed/ Medline, Cochrane Library, and Embase databases) and other potential sites. All observational studies were included. Heterogeneity between studies was checked using Cochrane Q test statistics and I2 test statistics and small study effects were checked using Egger's statistical test at a 5% significance level. Outcome measures were overall and specific underlying causes (obstetrics hemorrhage, hypertensive disorder pregnancy, pregnancy-related infection) rates of MNMs per 10,000 live births.

Result

The meta-analysis included 43 studies consisting of 77240 MNM cases. The pooled prevalence MNM per 1000 live births in Ethiopia was 54.33 (95% CI: 33.93 to 85.89). Between-study heterogeneity was high (I2 = 100%, P < 0.0001), with the highest rate observed in Amhara region (384.54 per 1000). The prevalence of obstetrics hemorrhage (14.56 per 1000) was higher than that of hypertensive disorder pregnancy (12.67 per 1000) and pregnancy-related infections (3.55 per 1000) were identified as underlying causes. Various factors, including socio demographic characteristics, previous medical and obstetrics history as well as access to and quality of care obtained, were associated with MNM.

Conclusion

Almost six women encounter near miss among a hundred live births in Ethiopia. Obstetric hemorrhage and hypertensive disorder pregnancy were the most common underlying causes of MNM. Both individual and facility level determinants were found to be associated with MNM. Considering the magnitude and identified factors, tailored measures should be taken at every stage of the continuum of care.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023395259.

Validation study of obstetric hospitalization data held on the Brazilian National Health System Hospital Information System for maternal morbidity surveillance: Brazil, 2021-2022

OBJECTIVE

To validate the Brazilian National Health System Hospital Information System (SIH/SUS) for maternal morbidity surveillance.

METHODS

This was a cross-sectional study conducted in 2021/2022, taking as its reference a national study on maternal morbidity (MMG) conducted in 50 public and 28 private hospitals; we compared SIH/SUS and MMG data for hospitalization frequency, reason and type of discharge and calculated sensitivity, specificity, positive and negative likelihood ratios for seven diagnoses and four procedures.

RESULTS

Hospitalizations identified on SIH/SUS (32,212) corresponded to 95.1% of hospitalizations assessed by MMG (33,867), with lower recording on SIH/SUS (85.5%) for private hospitals [10,036 (SIH/SUS)]; 11,742 (MMG)]; compared to MMG, SIH/SUS had a lower proportion of hospitalizations due to "complications during pregnancy" (9.7% versus 16.5%) as well as under-recording of all diagnoses and procedures assessed, except "ectopic pregnancy".

CONCLUSION

Better recording of diagnoses and procedures on SIH/SUS is essential for its use in maternal morbidity surveillance.

Long-term effects of neuraxial analgesia

PURPOSE OF REVIEW

This review article explores the potential longer-term implications of neuraxial analgesia in labour for both the mother and her child.

RECENT FINDINGS

Neuraxial techniques for labour analgesia are well tolerated and effective, and long-term adverse sequelae are rare. Labour epidural analgesia is not independently associated with long-term headache, backache, postnatal depression or anal sphincter injury, and evidence supports that epidurals may offer protection against severe maternal morbidity, particularly in women at a higher risk of complications. However, there is an increasing awareness that postdural puncture headache may be associated with chronic headache, back pain and postnatal depression, emphasizing the need for adequate follow-up until symptoms resolve.For the neonate, a growing body of evidence refutes any association between epidural analgesia in labour and the later development of autism spectrum disorder. The clinical significance of epidural related maternal fever remains uncertain and is a research priority.

SUMMARY

Women should continue to access the significant benefits of neuraxial analgesia in labour without undue concern about adverse sequelae for themselves or their offspring. Measures to prevent, appropriately manage and adequately follow-up women who have suffered complications of neuraxial analgesia, such as postdural puncture headache, are good practice and can mitigate the development of long-term sequelae.

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.

Preparedness for severe maternal morbidity in European hospitals: The MaCriCare study

PURPOSE

To evaluate obstetric units (OUs) and intensive care units (ICUs) preparedness for severe maternal morbidity (SMM).

METHODS

From September 2021 to January 2022, an international multicentre cross-sectional study surveyed OUs in 26 WHO Europe Region countries. We assessed modified early obstetric warning score usage (MEOWS), approaches to four SMM clinical scenarios, invasive monitoring availability in OUs, and access to high-dependency units (HDUs) and onsite ICUs. Within ICUs, we examined the availability of trained staff, response to obstetric emergencies, leadership, and data collection.

RESULTS

1133 responses were evaluated. MEOWS use was 34.5%. Non-obstetric early warning scores were being used. 21.4% (242) of OUs provided invasive monitoring in the OU. A quarter lacked access to onsite HDU beds. In cases of SMM, up to 13.8% of all OUs indicated the need for transfer to another hospital. The transfer rate was highest (74.0%) in small units. 81.9% of centers provided onsite ICU facilities to obstetric patients. Over 90% of the onsite ICUs provided daily specialist obstetric reviews but lacked immediate access to key resources: 3.4% - uterotonic drugs, 7.5% - neonatal resuscitation equipment, 9.2% - neonatal resuscitation team, 11.4% - perimortem cesarean section equipment. 41.2% reported obstetric data to a national database.

CONCLUSION

Gaps in provision exist for obstetric patients with SMM in Europe, potentially compromising patient safety and experience. MEOWS use in OUs was low, while access to invasive monitoring and onsite HDU and ICU facilities was variable. ICUs frequently lacked resources and did not universally collect obstetric data for quality control.

Epidural analgesia during labour and severe maternal morbidity: population based study

OBJECTIVES

To determine the effect of labour epidural on severe maternal morbidity (SMM) and to explore whether this effect might be greater in women with a medical indication for epidural analgesia during labour, or with preterm labour.

DESIGN

Population based study.

SETTING

All NHS hospitals in Scotland.

PARTICIPANTS

567 216 women in labour at 24+0 to 42+6 weeks' gestation between 1 January 2007 and 31 December 2019, delivering vaginally or through unplanned caesarean section.

MAIN OUTCOME MEASURES

The primary outcome was SMM, defined as the presence of ≥1 of 21 conditions used by the US Centers for Disease Control and Prevention (CDC) as criteria for SMM, or a critical care admission, with either occurring at any point from date of delivery to 42 days post partum (described as SMM). Secondary outcomes included a composite of ≥1 of the 21 CDC conditions and critical care admission (SMM plus critical care admission), and respiratory morbidity.

RESULTS

Of the 567 216 women, 125 024 (22.0%) had epidural analgesia during labour. SMM occurred in 2412 women (4.3 per 1000 births, 95% confidence interval (CI) 4.1 to 4.4). Epidural analgesia was associated with a reduction in SMM (adjusted relative risk 0.65, 95% CI 0.50 to 0.85), SMM plus critical care admission (0.46, 0.29 to 0.73), and respiratory morbidity (0.42, 0.16 to 1.15), although the last of these was underpowered and had wide confidence intervals. Greater risk reductions in SMM were detected among women with a medical indication for epidural analgesia (0.50, 0.34 to 0.72) compared with those with no such indication (0.67, 0.43 to 1.03; P<0.001 for difference). More marked reductions in SMM were seen in women delivering preterm (0.53, 0.37 to 0.76) compared with those delivering at term or post term (1.09, 0.98 to 1.21; P<0.001 for difference). The observed reduced risk of SMM with epidural analgesia was increasingly noticeable as gestational age at birth decreased in the whole cohort, and in women with a medical indication for epidural analgesia.

CONCLUSION

Epidural analgesia during labour was associated with a 35% reduction in SMM, and showed a more pronounced effect in women with medical indications for epidural analgesia and with preterm births. Expanding access to epidural analgesia for all women during labour, and particularly for those at greatest risk, could improve maternal health.

Severe maternal morbidity surveillance, temporal trends and regional variation: A population-based cohort study

OBJECTIVE

To quantify temporal trends and regional variation in severe maternal morbidity (SMM) in Sweden.

DESIGN

Cohort study.

POPULATION

Live birth and stillbirth deliveries in Sweden, 1999-2019.

METHODS

Types and subtypes of SMM were identified, based on a standard list (modified for Swedish clinical setting after considering the frequency and validity of each indicator) using diagnoses and procedure codes, among all deliveries at ≥22 weeks of gestation (including complications within 42 days of delivery). Contrasts between regions were quantified using rate ratios (RRs) and 95% confidence intervals (95% CIs). Temporal changes in SMM types and subtypes were described.

MAIN OUTCOME MEASURES

Types and subtypes of SMM.

RESULTS

There were 59 789 SMM cases among 2 212 576 deliveries, corresponding to 270.2 (95% CI 268.1-272.4) per 10 000 deliveries. Composite SMM rates increased from 236.6 per 10 000 deliveries in 1999 to 307.3 per 10 000 deliveries in 2006, before declining to 253.8 per 10 000 deliveries in 2019. Changes in composite SMM corresponded with temporal changes in severe haemorrhage rates, which increased from 94.9 per 10 000 deliveries in 1999 to 169.3 per 10 000 deliveries in 2006, before declining to 111.2 per 10 000 deliveries in 2019. Severe pre-eclampsia, eclampsia and HELLP (haemolysis, elevated liver enzymes and low platelet count) syndrome (103.8 per 10 000 deliveries), severe haemorrhage (133.7 per 10 000 deliveries), sepsis, embolism, disseminated intravascular coagulation, shock and severe mental health disorders were the most common SMM types. Rates of embolism, disseminated intravascular coagulation and shock, acute renal failure, cardiac complications, sepsis and assisted ventilation increased, whereas rates of surgical complications, severe uterine rupture and anaesthesia complications declined.

CONCLUSIONS

The observed spatiotemporal variations in composite SMM and SMM types provide substantive insights and highlight regional priorities for improving maternal health.

Genetic correlations and causal relationships between cardio-metabolic traits and sepsis

Cardio-metabolic traits have been reported to be associated with the development of sepsis. It is, however, unclear whether these co-morbidities reflect causal associations, shared genetic heritability, or are confounded by environmental factors. We performed three analyses to explore the relationships between cardio-metabolic traits and sepsis. Mendelian randomization (MR) study to evaluate the causal effects of multiple cardio-metabolic traits on sepsis. Global genetic correlation analysis to explore the correlations between cardio-metabolic traits and sepsis. Local genetic correlation (GC) analysis to explore shared genetic heritability between cardio-metabolic traits and sepsis. Some loci were further examined for related genes responsible for the causal relationships. Genetic associations were obtained from the UK Biobank data or published large-scale genome-wide association studies with sample sizes between 200,000 to 750,000. In MR, we found causality between BMI and sepsis (OR: 1.53 [1.4-1.67]; p < 0.001). Body mass index (BMI), which is confirmed by sensitivity analyses and multivariable MR adjusting for confounding factors. Global GC analysis showed a significant correlation between BMI and sepsis (rg = 0.55, p < 0.001). More cardio-metabolic traits were identified to be correlated to the sepsis onset such as CRP (rg = 0.37, p = 0.035), type 2 diabetes (rg = 0.33, p < 0.001), HDL (rg = - 0.41, p < 0.001), and coronary artery disease (rg = 0.43, p < 0.001). Local GC revealed some shared genetic loci responsible for the causality. The top locus 1126 was located at chromosome 7 and comprised genes HIBADH, JAZF1, and CREB5. The present study provides evidence for an independent causal effect of BMI on sepsis. Further detailed analysis of the shared genetic heritability between cardio-metabolic traits and sepsis provides the opportunity to improve the preventive strategies for sepsis.