Risk Of Severe Maternal Morbidity Research Articles

Comparison of Natural Language Processing of Clinical Notes With a Validated Risk-Stratification Tool to Predict Severe Maternal Morbidity

Risk-stratification tools are routinely used in obstetrics to assist care teams in assessing and communicating risk associated with delivery. Electronic health record data and machine learning methods may offer a novel opportunity to improve and automate risk assessment. To compare the predictive performance of natural language processing (NLP) of clinician documentation with that of a previously validated tool to identify individuals at high risk for maternal morbidity. This retrospective diagnostic study was conducted at Brigham and Women's Hospital and Massachusetts General Hospital, Boston, Massachusetts, and included individuals admitted for delivery at the former institution from July 1, 2016, to February 29, 2020. A subset of these encounters (admissions from February to December 2018) was part of a previous prospective validation study of the Obstetric Comorbidity Index (OB-CMI), a comorbidity-weighted score to stratify risk of severe maternal morbidity (SMM). Natural language processing of clinician documentation and OB-CMI scores. Natural language processing of clinician-authored admission notes was used to predict SMM in individuals delivering at the same institution but not included in the prospective OB-CMI study. The NLP model was then compared with the OB-CMI in the subset with a known OB-CMI score. Model discrimination between the 2 approaches was compared using the DeLong test. Sensitivity and positive predictive value for the identification of individuals at highest risk were prioritized as the characteristics of interest. This study included 19 794 individuals; 4034 (20.4%) were included in the original prospective validation study of the OB-CMI (testing set), and the remaining 15 760 (79.6%) composed the training set. Mean (SD) age was 32.3 (5.2) years in the testing cohort and 32.2 (5.2) years in the training cohort. A total of 115 individuals in the testing cohort (2.9%) and 468 in the training cohort (3.0%) experienced SMM. The NLP model was built from a pruned vocabulary of 2783 unique words that occurred within the 15 760 admission notes from individuals in the training set. The area under the receiver operating characteristic curve of the NLP-based model for the prediction of SMM was 0.76 (95% CI, 0.72-0.81) and was comparable with that of the OB-CMI model (0.74; 95% CI, 0.70-0.79) in the testing set (P = .53). Sensitivity (NLP, 28.7%; OB-CMI, 24.4%) and positive predictive value (NLP, 19.4%; OB-CMI, 17.6%) were comparable between the NLP and OB-CMI high-risk designations for the prediction of SMM. In this study, the NLP method and a validated risk-stratification tool had a similar ability to identify patients at high risk of SMM. Future prospective research is needed to validate the NLP approach in clinical practice and determine whether it could augment or replace tools requiring manual user input.

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 SMMand identify the main causes and risk factors contributing to SMM in HICs. PubMed, Cumulative IndextoNursing and Allied Health Literature(CINAHL), and Scopus databases were searched for articles published between 2010 and 2022, results were filtered, and 10 studieswere 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.

Severe Maternal Morbidity in Pregnancies Complicated by Fetal Congenital Heart Disease

BackgroundMaternal risk factors for fetal congenital heart disease (CHD) may also be associated with delivery complications in the mother. ObjectivesThis study aimed to determine the prevalence of and risk factors for severe maternal morbidity (SMM) and maternal hospital transfer in pregnancies complicated by fetal CHD. MethodsA population-based retrospective cohort study utilizing linked Ohio birth certificates and birth defect data for all live births from 2011 to 2015 was performed. The primary outcome was composite SMM. Secondary outcome was maternal hospital transfer prior to delivery. Pregnancies with isolated fetal CHD were compared to pregnancies with no fetal anomalies and isolated fetal cleft lip/palate (CLP). ResultsA total of 682,929 mothers with live births were included. Of these, 5,844 (0.85%) mothers had fetal CHD, and 963 (0.14%) had fetal CLP. SMM in pregnancies with fetal CHD was higher than that in those with no anomalies (3.6% vs 1.9%, P < 0.001) or CLP (3.6% vs 1.9%, P = 0.006). After adjusting for known risk factors, fetal CHD remained independently associated with SMM when compared to no fetal anomalies (adjusted relative risk [adjRR]: 1.81, 95% CI: 1.58-2.08) and CLP (adjRR: 1.81, 95% CI: 1.12-2.92). Maternal hospital transfer occurred more frequently in fetal CHD cases vs for those without fetal anomalies with an increased adjusted risk (adjRR: 3.65, 95% CI: 3.14-4.25). ConclusionsPregnancies with isolated fetal CHD have increased risk of SMM and maternal hospital transfer after adjusting for known risk factors. This may inform delivery planning for mothers with fetal CHD. Understanding the biological mechanisms may provide insight into other adverse perinatal outcomes in this population.

Racial/ethnic disparities in severe maternal morbidity: An intersectional lifecourse approach.

Despite long-existing calls to address alarming racial/ethnic gaps in severe maternal morbidity (SMM), research that considers the impact of intersecting social inequities on SMM risk remains scarce. Invoking intersectionality theory, we sought to assess SMM risk at the nexus of racial/ethnic marginalization, weathering, and neighborhood/individual socioeconomic disadvantage. We used birth hospitalization records from California across 20 years (1997-2017, N = 9,806,406) on all live births ≥20 weeks gestation. We estimated adjusted average predicted probabilities of SMM at the combination of levels of race/ethnicity, age, and neighborhood deprivation or individual socioeconomic status (SES). The highest risk of SMM was observed among Black birthing people aged ≥35 years who either resided in the most deprived neighborhoods or had the lowest SES. Black birthing people conceptualized to be better off due to their social standing (aged 20-34 years and living in the least deprived neighborhoods or college graduates) had comparable and at times worse risk than White birthing people conceptualized to be worse off (aged ≥35 years and living in the most deprived neighborhoods or had a high-school degree or less). Our findings highlight the need to explicitly address structural racism as the driver of racial/ethnic health inequities and the imperative to incorporate intersectional approaches.

Severe maternal morbidity following stillbirth in Western Australia 2000–2015: a population-based study

PurposeThere is scant literature about the management of stillbirth and the subsequent risk of severe maternal morbidity (SMM). We aimed to assess the risk of SMM associated with stillbirths compared with live births and whether this differed by the presence of maternal comorbidities.MethodsIn this retrospective cohort study, we used a population-based dataset of all stillbirths and live births ≥ 20 weeks’ gestation in Western Australia between 2000 and 2015. SMM was identified using a published Australian composite for use with routinely collected hospital morbidity data. Maternal comorbidities were identified in the Hospital Morbidity Data Collection or the Midwives Notification System using a modified Australian chronic disease composite. Multivariable Poisson regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for factors associated with SMM in analyses stratified by the presence of maternal comorbidities. Singleton and multiple pregnancies were examined separately.ResultsThis study included 458,639 singleton births (2319 stillbirths and 456,320 live births). The adjusted RRs for SMM among stillbirths were 2.30 (95% CI 1.77, 3.00) for those without comorbidities and 4.80 (95% CI 4.11, 5.59) (Interaction P value < 0.0001) for those with comorbidities compared to live births without and with comorbidities, respectively.ConclusionIn Western Australia between 2000 and 2015, mothers of stillbirths both with and without any maternal comorbidities had an increased risk of SMM compared with live births. Further investigation into why women who have had a stillbirth without any existing conditions or pregnancy complications develop SMM is warranted.

Patient Race and Racial Composition of Delivery Unit Associated With Disparities in Severe Maternal Morbidity: A Multistate Analysis 2007–2014

(Int J Obstet Anesth. 2021;47:103160) Black women have a higher rate of severe maternal morbidity (SMM) than non-Hispanic White women. Although investigations of SMM and race/ethnicity have typically centered around inequalities at the patient level, SMM is also associated with quality of care at the hospital level. Mothers who give birth in hospitals that serve a disproportionate number of black women (Black-serving hospitals) are more likely to have SMM than mothers who deliver at hospitals that serve fewer black women. Likewise, mothers who deliver at hospitals with a relatively greater proportion of patients without insurance or on public insurance (safety-net burden) have an increased risk for SMM. Few studies have investigated the relationship between hospital-level and patient‐level factors and risk for SMM. Using State Inpatient Databases (SID), data from Healthcare and Cost and Utilization Project (HCUP), and Agency for Healthcare Research and Quality (AHRQ) for the years 2007–2014, this retrospective observational study attempted to calculate the odds of SMM with the hospital-level factors of safety-net burden and Black-serving classification, both separately and in conjunction with the patient’s race/ethnicity.

Racial and ethnic differences in severe maternal morbidity among singleton stillbirth deliveries

Despite growing evidence suggesting racial or ethnic disparities in the risk of severe maternal morbidity among live births, there is little research investigating potential differences in severe maternal morbidity risk among stillbirths across race and ethnicity. This study aimed to compare the risk of severe maternal morbidity by race and ethnicity among patients with singleton stillbirth pregnancies. We used the California Linked Birth File database to perform a retrospective analysis of singleton stillbirth pregnancies delivered at 20 to 42 weeks' gestation between 2007 and 2011. The database contained information from fetal death certificates linked to maternal hospital discharge records. We defined severe maternal morbidity using the Centers for Disease Control and Prevention composite severe maternal morbidity indicator and compared rates of severe maternal morbidity across racial and ethnic groups. Multivariable regression analysis was used to examine how race and ethnicity were associated with severe maternal morbidity risk after accounting for the influence of patients' clinical risk factors, socioeconomic characteristics, and attributes of the delivery hospital. Of the 9198 patients with singleton stillbirths, 533 (5.8%) experienced severe maternal morbidity. Non-Hispanic Black patients had a significantly higher risk of severe maternal morbidity (10.6% vs 5.2% in non-Hispanic White patients, 5.2% in Hispanic patients, and 5.1% in patients with other race or ethnicity; P<.001). The higher risk of severe maternal morbidity among non-Hispanic Black patients persisted even after adjusting for patients' clinical, socioeconomic, and hospital characteristics (adjusted odds ratio for non-Hispanic Black vs non-Hispanic White patients, 1.74; 95% confidence interval, 1.21-2.50). Further analysis separating blood-transfusion and nontransfusion severe maternal morbidity showed a higher risk of blood transfusion in non-Hispanic Black patients, which remained significant after adjusting for patients' clinical, socioeconomic, and hospital characteristics (adjusted odds ratio for non-Hispanic Black vs non-Hispanic White patients, 1.64; 95% confidence interval, 1.11-2.43). However, the higher risk of nontransfusion severe maternal morbidity in non-Hispanic Black patients was no longer significant after adjusting for patients' clinical risk factors (adjusted odds ratio for non-Hispanic Black vs non-Hispanic White patients, 1.38; 95% confidence interval, 0.83-2.30). Severe maternal morbidity occurred in 5.8% of patients with a singleton stillbirth. Risk of severe maternal morbidity in stillbirth was higher in patients with non-Hispanic Black race, which was likely owing to a higher risk of hemorrhage, as evidenced by increased rate of blood transfusion.

Society for Maternal-Fetal Medicine Consult Series #63: Cesarean scar ectopic pregnancy

Cesarean scar ectopic pregnancy is a complication in which an early pregnancy implants in the scar from a previous cesarean delivery. This condition presents a substantial risk for severe maternal morbidity and mortality because of challenges in securing a prompt diagnosis. Ultrasound is the primary imaging modality for cesarean scar ectopic pregnancy diagnosis, although a correct and timely determination can be difficult. Surgical, medical, and minimally invasive therapies have been described for cesarean scar ectopic pregnancy management, but the optimal treatment is unknown. Patients who decline treatment of a cesarean scar ectopic pregnancy should be counseled regarding the risk for severe morbidity. The following are the Society for Maternal-Fetal Medicine recommendations: we recommend against expectant management of cesarean scar ectopic pregnancy (GRADE 1B); we suggest that operative resection (with transvaginal or laparoscopic approaches when possible) or ultrasound-guided uterine aspiration be considered for the surgical management of cesarean scar ectopic pregnancy and that sharp curettage alone be avoided (GRADE 2C); we suggest intragestational methotrexate for the medical treatment of cesarean scar ectopic pregnancy, with or without other treatment modalities (GRADE 2C); we recommend that systemic methotrexate alone not be used to treat cesarean scar ectopic pregnancy (GRADE 1C); in patients who choose expectant management and continuation of a cesarean scar ectopic pregnancy, we recommend repeated cesarean delivery between 34 0/7 and 35 6/7 weeks of gestation (GRADE 1C); we recommend that patients with a cesarean scar ectopic pregnancy be advised on the risks of another pregnancy and counseled regarding effective contraceptive methods, including long-acting reversible contraception and permanent contraception (GRADE 1C).

Association of Prepregnancy Body Mass Index With Risk of Severe Maternal Morbidity and Mortality Among Medicaid Beneficiaries

The association between body mass index (BMI, which is calculated as weight in kilograms divided by height in meters squared) and severe maternal morbidity (SMM) and/or mortality is uncertain, judging from the current evidence. To examine the association between prepregnancy BMI and SMM and/or mortality through 1 year post partum and to identify both the direct and indirect implications of maternal obesity for SMM and/or mortality by examining hypertensive disorders and pregestational diabetes as potential mediators. This population-based cohort study was conducted from March to October 2021 using the vital records and linked Medicaid claims data in the state of Ohio from January 1, 2012, through December 31, 2017. The cohort comprised pregnant Medicaid beneficiaries who delivered at 20 weeks' gestation or later and had prepregnancy BMI information. The primary exposure was maternal prepregnancy BMI, which was categorized as follows: underweight (<18.5), healthy weight (18.5-24.9), overweight (25.0-29.9), class 1 obesity (30.0-34.9), class 2 obesity (35.0-39.9), and class 3 obesity (≥40.0). The primary outcome was a composite of SMM (defined using Centers for Disease Control and Prevention criteria) and/or maternal mortality between 20 weeks' gestation and 1 year post partum. Additional periods were assessed, including 20 weeks' gestation through delivery hospitalization and 20 weeks' gestation through 42 days post partum. Generalized estimating equation models were used to estimate adjusted relative risks (aRRs) for the primary outcome according to BMI category. Maternal hypertensive diseases and pregestational diabetes were assessed as potential meditators. In a cohort of 347 497 pregnancies among 276 691 Medicaid beneficiaries (median [IQR] maternal age at delivery, 25 [21-29] years; 210 470 non-Hispanic White individuals [60.6%]), the prevalence of maternal obesity was 30.5% (n = 106 031). Composite SMM and/or mortality outcome occurred in 5.3% of pregnancies (n = 18 398). Overweight (aRR, 1.07; 95% CI, 1.03-1.11) and obesity (class 1: aRR, 1.19 [95% CI, 1.14-1.24]; class 2: aRR, 1.37 [95% CI, 1.30-1.44]; class 3: aRR, 1.71 [95% CI, 1.63-1.80]) were associated with an elevated risk of SMM and/or mortality during pregnancy to 1 year post partum compared with healthy BMI. Similar findings were observed when the follow-up period was shortened to 42 days post partum or the delivery hospitalization. Hypertension mediated 65.1% (95% CI, 64.6%-65.6%) of the association between obesity and the primary outcome. Results of this study showed that maternal prepregnancy obesity was associated with an elevated risk of SMM and/or mortality. Hypertensive disorders appeared to mediate this association, suggesting that improved prevention and management of hypertensive disorders in pregnancy may reduce morbidity and mortality in individuals with obesity.

Maternal and obstetric outcomes of listeria pregnancy: insights from a national cohort

Objective We sought to evaluate and describe the maternal and obstetric morbidity associated with Listeria infection in pregnancy. Methods Retrospective cohort of pregnant women using the 2007-2018 National Inpatient Sample. Pregnant women with discharge diagnosis codes consistent with Listeria infection were identified. Outcomes of deliveries complicated by Listeria infection were compared to those of delivery without this infection. The primary outcome was a composite of severe maternal morbidity. Secondary outcomes included components of the composite, maternal length of stay, mode of delivery, stillbirth, and preterm delivery. Results We identified 134 maternity associated hospitalizations for Listeria (weighted national estimate 666), of which 72 (weighted national estimate of 358) were delivery admissions. Delivery admissions complicated by Listeria resulted in higher rates of severe maternal morbidity than those without, (30.9% vs. 1.6%, p<.001). In adjusted analyses, women with Listeria had 21.2-fold higher risk of severe maternal morbidity (95% CI: 14.0, 31.9) when compared to those without Listeria. Specifically, Listeria delivery admissions had higher rates of acute respiratory distress syndrome (2.8% vs. 0.1%, p<.001), mechanical ventilation (1.4% vs. 0.0%, p<.001), sepsis (28.1% vs. 0.1%, p<.001), and shock (1.4% vs. 0.0%, p<.001). Listeria delivery admissions also had higher rates of preterm birth (61.3% vs. 7.7%, p < 0.001) and stillbirth (13.5% vs. 0.7%, p<.001). Women hospitalized or delivered with Listeria infection were also more likely to have a cesarean delivery (57.9% vs. 32.9, p<.001) and the average length of stay for women with Listeria was also longer (4.0 days vs. 2.3 days, p<.001). Conclusions Women with Listeria infection in pregnancy have higher rates of severe maternal morbidity, specifically increased risk of sepsis, septic shock, and acute respiratory distress syndrome. Among delivery hospitalizations, these women also have higher rates of preterm birth and stillbirth.

The Association Between Adequate Prenatal Care and Severe Maternal Morbidity Among Teenage Pregnancies: A Population-Based Cohort Study.

BackgroundThe aim of this study was to examine whether inadequate prenatal care affect the risk of severe maternal morbidity in teenage pregnancies.MethodsWe included 23,202 delivery cases among adolescent mothers aged between 13 and 19 years old with ≥ 37 weeks' gestational age. Data were derived from the National Health Insurance Service National Delivery Cohort in Korea between 2003 and 2018. We used a generalized estimating equation model while adjusting for numerous covariates to determine the adjusted relative risk (RR) associated with severe maternal morbidity. The main outcome measures were severe maternal morbidity and the Kessner Adequacy of Prenatal Care Index.ResultsSevere maternal morbidity occurred in 723 (3.1%) of the 23,202 investigated delivery cases. The risk of severe maternal morbidity was 1.8-fold higher among adolescent mothers who had received inadequate prenatal care (RR, 1.81, 95% confidence interval [CI], 1.39–2.37) and 1.6-fold higher among those who had received intermediate prenatal care (RR, 1.59, 95% CI, 1.33–1.87) compared to those with adequate prenatal care. Synergistic effects of inadequate prenatal care and maternal comorbidities affected severe maternal morbidity.ConclusionThis study confirmed that inadequate prenatal care is associated with increased risk of severe maternal morbidity among pregnant teenagers. Notably, maternal comorbidity and inadequate prenatal care produced synergistic effects on severe maternal morbidity. Public health policy makers should focus on the development and implementation of programs to ensure that adequate prenatal care and financial/healthcare support is provided to teenage mothers during their pregnancies.

Does the Quality of Postpartum Hemorrhage Local Protocols Improve the Identification and Management of Blood Loss after Vaginal Deliveries? A Multicenter Cohort Study.

Substandard care, which can result from a delayed recognition of the severity of blood loss, can increase maternal morbidity. Our objectives were to assess the incidence of postpartum hemorrhage (PPH) and of second-line procedures in maternity units according to the quality of their PPH protocol. We used a mixed design, a prospective cohort (3442 women with PPH after vaginal delivery; February–July 2011), and an audit of the written protocols (177 French maternity units; September 2010–June 2011). A quality score was calculated for the protocol of each unit. Maternity units were classified into three categories according to this score: category 1 (total score: 0–8), category 2 (9–12.5), and category 3 (>12.5). The PPH incidence (>500 mL) was 3.2%, 3.3% and 4.6% among maternity units in categories 1, 2 and 3, respectively (p < 0.0001). The incidence of severe maternal morbidity (surgery and/or artery embolization and/or blood transfusion) was higher among maternity units in category 1 (54.8%; 95% CI: 51.9, 57.7) than in either category 2 (50.1%; 95% CI: 47.8, 52.5) or 3 (38.0%; 95% CI: 33.8, 42.4]) (p < 0.0001). The risks of severe maternal morbidity were lower for category 3 than category 1 and 2 (respectively, adjusted RR 0.68, 95% CI 0.60–0.86 and 0.77, 95% CI 0.68–0.87). Finally, maternity units with higher scores identified PPH better and used fewer curative second-line procedures.

Evaluation of Adverse Pregnancy Outcomes in Physicians Compared With Nonphysicians

Physicians may be at risk of pregnancy complications due to prolonged work hours, overnight shifts, occupational hazards, and older maternal age at first birth compared with nonphysicians. Observational studies of physicians, including comparisons across physician specialties, are needed. To compare adverse maternal and perinatal outcomes between pregnant physicians and nonphysicians and between physicians of different specialties. A population-based retrospective cohort study was conducted in Ontario, Canada. Participants included physicians and nonphysician comparators residing in high-income areas who experienced a birth at 20 or more weeks' gestation from April 1, 2002, to November 26, 2018. Data analysis was performed from December 2020 to March 2022. Physician occupation and physician specialty. Severe maternal morbidity (in pregnancy and up to 42 days' post partum) and severe neonatal morbidity (up to hospital discharge among live-born infants) were the primary outcomes. Logistic regression under a generalized estimating equations approach was used to compare outcomes between physicians and nonphysicians, accounting for potentially more than 1 pregnancy per woman. Odds ratios were adjusted (aOR) for maternal age, parity, previous preterm birth, calendar year, immigration status, comorbidities, multiple gestation, and mode of delivery. A total of 10 489 births occurred among 6161 licensed physicians, and 298 683 births occurred among 211 191 nonphysician counterparts. Physicians were older (median [IQR] age, 34 [31-36] vs 32 [29-35] years) and more likely to be nulliparous (5049 [48.1%] vs 128 961 [43.2%]) compared with nonphysicians. Severe maternal morbidity was more likely to occur among physicians than nonphysicians (unadjusted OR, 1.21; 95% CI, 1.04-1.41) but not after adjusting for study covariates (aOR, 1.13; 95% CI, 0.97-1.32). Severe neonatal morbidity was less likely to occur among infants of physicians than infants of nonphysicians (aOR, 0.79; 95% CI, 0.72-0.87). Compared with family physicians, neither nonsurgical specialists (aOR, 1.12; 95% CI, 0.82-1.53) nor surgical specialists (aOR, 1.43; 95% CI, 0.74-2.76) were at increased risk of severe maternal morbidity. Similar findings were observed for severe neonatal morbidity (nonsurgical specialists: aOR, 0.98; 95% CI, 0.80-1.19; surgical specialists: aOR, 1.08; 95% CI, 0.68-1.71). The findings of this study suggest that female physicians may be at slightly higher risk of severe maternal morbidity. This association appeared to be mediated by their tendency to delay childbearing compared with nonphysicians. Newborns of physicians appear to experience less morbidity. Such differences were not observed between physician specialty groups.

Comparison of severe maternal morbidity in pregnancy by modified World Health Organization Classification of maternal cardiovascular risk

BackgroundTo compare rates of severe maternal morbidity (SMM) for pregnant patients with a cardiac diagnosis classified by the modified World Health Organization (mWHO) classification to those without a cardiac diagnosis. MethodsThis retrospective study using the 2015-2019 Nationwide Readmissions Database identified hospitalizations, comorbidities, and outcomes using diagnosis and procedure codes. The primary exposure was cardiac diagnosis, classified into low-risk (mWHO class I and II) and moderate-to-high-risk (mWHO class II/III, III, or IV). The primary outcome was SMM or death during the delivery hospitalization; secondary outcomes included cardiac-specific SMM during delivery hospitalizations and readmissions after the delivery hospitalization. ResultsA weighted national estimate of 14,995,122 delivery admissions was identified, including 46,541 (0.31%) with mWHO I-II diagnoses and 37,330 (0.25%) with mWHO II/III-IV diagnoses. Patients with mWHO II/III-IV diagnoses experienced SMM at the highest rates (22.8% vs 1.6% for no diagnosis; with adjusted relative risk (aRR) of 5.67 [95% CI: 5.36-6.00]). The risk of death was also highest for patients with mWHO II/III-IV diagnoses (0.3% vs <0.1% for no diagnosis; aRR 18.07 [95% CI: 12.25-26.66]). Elevated risk of SMM and death persisted to 11 months postpartum for those patients with mWHO II/III-IV diagnoses. ConclusionsIn this nationwide database, SMM is highest among individuals with moderate-to-severe cardiac disease based on mWHO classification. This risk persists in the year postpartum. These results can be used to enhance pregnancy counseling.

Deliveries Among Patients Aged 11-19 Years and Risk for Adverse Pregnancy Outcomes.

To characterize delivery hospitalization trends of patients aged 11-19 years and associated comorbidities and outcomes. For this repeated cross-sectional analysis, deliveries to patients aged 11-54 years were identified in the 2000-2018 National Inpatient Sample. Temporal trends in deliveries to patients aged 11-14 years and 15-19 years were analyzed using joinpoint regression to estimate average annual percent change with 95% CIs. The association of deliveries among patients aged 11-19 years with other comorbid conditions was analyzed. The relationship between delivery among patients aged 11-19 years and adverse maternal outcomes was analyzed with unadjusted and adjusted logistic regression models, with unadjusted and adjusted odds ratios (aORs) as measures of effect. An estimated 73,198,153 delivery hospitalizations from 2000 to 2018 were included, of which 88,363 were to patients aged 11-14 years and 6,359,331 were to patients aged 15-19 years. The proportion of delivery hospitalizations among patients aged 11-14 years decreased from 2.1 to 0.4 per 1,000 from 2000 to 2018 (average annual percent change -7.8%, 95% CI -8.5% to -7.2%). Deliveries to patients aged 15-19 years decreased from 2000 to 2018, from 11.5% to 4.8% of all deliveries (average annual percent change -4.9%, 95% CI -5.6% to -4.3%). For deliveries among patients aged 11-19 years, rates of obesity, mental health conditions, substance use disorder, asthma, and pregestational and gestational diabetes all significantly increased over the study period. From 2000 to 2018, rates of severe maternal morbidity (average annual percent change 2.4%, 95% CI 1.6-3.1%), postpartum hemorrhage (average annual percent change 2.4%, 95% CI 1.4-3.4%), cesarean delivery (average annual percent change 1.3%, 95% CI 0.9-1.7%), and hypertensive disorders of pregnancy (average annual percent change 3.3%, 95% CI 2.8-3.8%) all increased significantly among deliveries to patients aged 11-19 years. Compared with deliveries to patients aged 20-54 years, deliveries to patients aged 11-14 years were associated with increased risk for severe maternal morbidity (aOR 1.73, 95% CI 1.49-2.00), hypertensive disorders of pregnancy (aOR 1.79, 95% CI 1.71-1.88), and postpartum hemorrhage (aOR 1.37, 95% CI 1.27-1.49). Deliveries among patients aged 11-19 years have decreased, but both comorbidity and risk for adverse outcomes increased among this age group.

Primary Cesarean Deliveries of Term Singletons Prior to or in Labour and Risks of Severe Maternal Morbidity: A Comparison of Canadian Tiers of Obstetric Services

To estimate the rates of severe maternal morbidity/mortality associated with primary cesarean sections (PCS) in different tiers of obstetrics services (ToS) in Canada.

Maternal Morbid Obesity Is Associated With an Increased Risk of Severe Maternal Morbidity [A234

INTRODUCTION: Prepregnancy obesity (body mass index [BMI]≥30) has been consistently associated with maternal morbidity. The rate of morbid obesity (BMI≥40) appears to be increasing. This study investigated whether morbid obesity was associated with severe maternal morbidity in a population cohort. METHODS: Internal review board exemption was obtained. We identified 197,822 patients using the birth-certificate-based New York Statewide Perinatal Data System from 2010 to 2020. Women were divided into two categories, those with prepregnancy BMI &lt;40 and those with prepregnancy BMI ≥40 (morbid obesity). The risk of severe maternal morbidity (maternal transfusion, intensive care unit admission, unplanned hysterectomy, and unplanned reoperation) was compared. We also compared the risk of cesarean delivery, hypertensive disorders of pregnancy, and gestational diabetes. Chi-square and t tests were used to compare categorical and continuous variables respectively. RESULTS: We identified 197,822 deliveries, of which 13,120 (6.63%) were complicated by maternal morbid obesity. Morbidly obese women had a significantly higher risk of severe morbidity (RR, 1.16; 95% CI, 1.003–1.33). The risk of intensive care unit admission was significantly increased (RR, 1.84; 95% CI, 1.35–2.53), but blood transfusion, unplanned hysterectomy, and unplanned reoperation were unchanged. CONCLUSION: Morbid obesity was associated with increased severe maternal morbidity specifically due to maternal intensive care unit admission. This may indicate a higher risk of severe medical complications and likely represents a higher risk of maternal mortality.

Severe maternal morbidity and other perinatal complications among women with physical, sensory, or intellectual and developmental disabilities.

Little is known about severe maternal morbidity (SMM) among women with disabilities. We assessed differences in SMM and other perinatal complications by presence and type of disability. We hypothesised that SMM and other complications would be more common in births to women with disabilities than to women without disabilities. We conducted a retrospective cohort study of California births from 2000 to 2012, using birth and death certificate data linked with hospital discharge data. We included singleton deliveries with gestational age of 23-42weeks. We classified women as having any disability or not and identified disability type (physical, hearing, vision, intellectual/developmental disabilities [IDD]). Our primary outcome was a composite indicator of SMM. Secondary outcomes included additional perinatal complications: gestational hypertension, preeclampsia, gestational diabetes, venous thromboembolism, chorioamnionitis, puerperal endometritis and mental health disorders complicating pregnancy, childbirth or the puerperium. We used modified Poisson regression to obtain covariate-adjusted relative risks (RR) and 95% confidence intervals (CI) for the association of disability status and type with SMM and secondary outcomes. Of 5,787,090 deliveries, 33,044 (0.6%) were to women with disabilities. Of these, 311 per 10,000 were complicated by SMM, compared with 84 per 10,000 deliveries to women without disabilities. In multivariable analyses, risk of SMM for births to women with disabilities was nearly three times that for women without disabilities (RR 2.84, 95% CI 2.67, 3.02). Proportion and risk of SMM were greatest for vision disability (793 per 10,000; RR 4.04, 95% CI 3.41, 4.78). Secondary outcomes were also more common among women with disabilities. In particular, more than a third of births to women with IDD (37.4%) were complicated by mental health disorders (versus 2.2% for women without disabilities). As hypothesised, SMM and other perinatal complications were more common among women with disabilities than among women without disabilities.

Natural language processing of admission notes to predict severe maternal morbidity during the delivery encounter

Severe maternal morbidity and mortality remain public health priorities in the United States, given their high rates relative to other high-income countries and the notable racial and ethnic disparities that exist. In general, accurate risk stratification methods are needed to help patients, providers, hospitals, and health systems plan for and potentially avert adverse outcomes. Our objective was to understand if machine learning methods with natural language processing of history and physical notes could identify a group of patients at high risk of maternal morbidity on admission for delivery without relying on any additional patient information (eg, demographics and diagnosis codes). This was a retrospective study of people admitted for delivery at 2 hospitals (hospitals A and B) in a single healthcare system between July 1, 2016, and June 30, 2020. The primary outcome was severe maternal morbidity, as defined by the Centers for Disease Control and Prevention; furthermore, we examined nontransfusion severe maternal morbidity. Clinician documents designated as history and physical notes were extracted from the electronic health record for processing and analysis. A bag-of-words approach was used for this natural language processing analysis (ie, each history or physical note was converted into a matrix of counts of individual words (or phrases) that occurred within the document). The least absolute shrinkage and selection operator models were used to generate prediction probabilities for severe maternal morbidity and nontransfusion severe maternal morbidity for each note. Model discrimination was assessed via the area under the receiver operating curve. Discrimination was compared between models using the DeLong test. Calibration plots were generated to assess model calibration. Moreover, the natural language processing models with history and physical note texts were compared with validated obstetrical comorbidity risk scores based on diagnosis codes. There were 13,572 delivery encounters with history and physical notes from hospital A, split between training (Atrain, n=10,250) and testing (Atest, n=3,322) datasets for model derivation and internal validation. There were 23,397 delivery encounters with history and physical notes from hospital B (Bvalid) used for external validation. For the outcome of severe maternal morbidity, the natural language processing model had an area under the receiver operating curve of 0.67 (95% confidence interval, 0.63-0.72) and 0.72 (95% confidence interval, 0.70-0.74) in the Atest and Bvalid datasets, respectively. For the outcome of nontransfusion severe maternal morbidity, the area under the receiver operating curve was 0.72 (95% confidence interval, 0.65-0.80) and 0.76 (95% confidence interval, 0.73-0.79) in the Atest and Bvalid datasets, respectively. The calibration plots demonstrated the bag-of-words model's ability to distinguish a group of individuals at a substantially higher risk of severe maternal morbidity and nontransfusion severe maternal morbidity, notably those in the top deciles of predicted risk. Areas under the receiver operating curve in the natural language processing-based models were similar to those generated using a validated, retrospectively derived, diagnosis code-based comorbidity score. In this practical application of machine learning, we demonstrated the capabilities of natural language processing for the prediction of severe maternal morbidity based on provider documentation inherently generated at the time of admission. This work should serve as a catalyst for providers, hospitals, and electronic health record systems to explore ways that artificial intelligence can be incorporated into clinical practice and evaluated rigorously for their ability to improve health.

Severe maternal morbidity in pregnant patients with SARS-CoV-2 infection

BACKGROUNDAlthough the increased risk for severe illness and adverse pregnancy outcomes associated with SARS-CoV-2 infection during pregnancy is well described, the association of infection with severe maternal morbidity has not been well characterized.OBJECTIVEThis study aimed to evaluate the risk for severe maternal morbidity associated with SARS-CoV-2 infection during pregnancy.STUDY DESIGNThis was a multicenter retrospective cohort study of all pregnant patients who had a SARS-CoV-2 test done and who delivered in a New York health system between March 1, 2020 and March 1, 2021. Patients with missing test results were excluded. The primary outcome of severe maternal morbidity, derived from the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine example list of diagnoses and complications, was compared between the following 2 groups: patients who tested positive for SARS-CoV-2 during pregnancy and patients who tested negative. Secondary outcomes included subgroups of severe maternal morbidity. Multivariable logistic regression was used to adjust for potential confounders such as maternal demographics, neighborhood socioeconomic status, hospital location, and pregnancy-related complications. A subanalysis was performed to determine if the risk for severe obstetrical hemorrhage and hypertension-associated or neurologic morbidity differed based on the timing of SARS-CoV-2 infection between those who tested positive for SARS-CoV-2 at their delivery hospitalization (ie, active infection) and those who tested positive during pregnancy but negative at their delivery hospitalization (ie, resolved infection).RESULTSOf the 22,483 patients included, 1653 (7.4%) tested positive for SARS-CoV-2 infection. Patients with SARS-CoV-2 infection were more commonly Black, multiracial, Hispanic, non-English speaking, used Medicaid insurance, were multiparous, and from neighborhoods with a lower socioeconomic status. Patients with SARS-CoV-2 infection were at an increased risk for severe maternal morbidity when compared with those without infection (9.3 vs 6.5%; adjusted odds ratio, 1.52; 95% confidence interval, 1.21–1.88). Patients with SARS-CoV-2 infection were also at an increased risk for severe obstetrical hemorrhage (1.1% vs 0.5%; adjusted odds ratio, 1.78; 95% confidence interval, 1.04–2.88), pulmonary morbidity (2.0% vs 0.5%; adjusted odds ratio, 3.90; 95% confidence interval, 2.52–5.89), and intensive care unit admission (1.8% vs 0.5%; adjusted odds ratio, 3.29; 95% confidence interval, 2.09–5.04) when compared with those without infection. The risk for hypertension-associated or neurologic morbidity was similar between the 2 groups. The timing of SARS-CoV-2 infection (whether active or resolved at time of delivery) was not associated with the risk for severe obstetrical hemorrhage or hypertension-associated or neurologic morbidity when compared with those without infection.CONCLUSIONSARS-CoV-2 infection during pregnancy was associated with an increased risk for severe maternal morbidity, severe obstetrical hemorrhage, pulmonary morbidity, and intensive care unit admission. These data highlight the need for obstetrical unit preparedness in caring for patients with SARS-CoV-2 infection, continued public health efforts aimed at minimizing the risk for infection, and support in including this select population in investigational therapy and vaccine trials.