Validation of ICD-10 Codes for Severe Maternal Morbidity at Delivery in a Public Hospital.

BACKGROUND: Severe maternal morbidity is a composite measure of serious obstetric complications that is often identified in administrative data using the International Classification of Diseases (ICD) diagnosis and procedure codes for a set of 21 indicators. Prior studies of screen-positive cases have demonstrated low predictive value for ICD codes relative to the medical record. To our knowledge, the validity of ICD-10 codes for identifying severe maternal morbidity has not been fully described. METHODS: We estimated the sensitivity, specificity, positive predictive value, and negative predictive value of ICD-10 codes for severe maternal morbidity occurring at delivery, compared with medical record abstraction (gold standard), for 1,000 deliveries that took place during 2016-2018 at a large, public hospital. RESULTS: We identified a total of 67 cases of severe maternal morbidity using the ICD-10 definition and 74 cases in the medical record. The sensitivity was 26% (95% confidence interval [CI] = 16%, 37%), the positive predictive value was 28% (95% CI = 18%, 41%), the specificity was 95% (95% CI = 93%, 96%), and the negative predictive value was 94% (95% CI = 92%, 96%). CONCLUSIONS: The validity of ICD-10 codes for severe maternal morbidity in our high-burden population was poor, suggesting considerable potential for bias.

Utilization and Comparative Effectiveness of Uterine Artery Embolization versus Hysterectomy for Severe Postpartum Hemorrhage: A National Inpatient Sample Study.

PURPOSE: To identify differences in mortality or length of hospital stay for mothers treated with uterine artery embolization (UAE) or hysterectomy for severe postpartum hemorrhage (PPH), as well as to analyze whether geographic or clinical determinants affected the type of therapy received. MATERIALS AND METHODS: This National Inpatient Sample study from 2005 to 2017 included all patients with live-birth deliveries. Severe PPH was defined as PPH that required transfusion, hysterectomy, or UAE. Propensity score weighting-adjusted demographic, maternal, and delivery risk factors were used to assess mortality and prolonged hospital stay. RESULTS: Of 9.8 million identified live births, PPH occurred in 31.0 per 1,000 cases. The most common intervention for PPH was transfusion (116.4 per 1,000 cases of PPH). Hysterectomy was used more frequently than UAE (20.4 vs 12.9 per 1,000 cases). The following factors predicted that hysterectomy would be used more commonly than UAE: previous cesarean delivery, breech fetal position, placenta previa, transient hypertension during pregnancy without pre-eclampsia, pre-existing hypertension without pre-eclampsia, pre-existing hypertension with pre-eclampsia, unspecified maternal hypertension, and gestational diabetes (all P < .001). Delivery risk factors associated with greater utilization of hysterectomy over UAE included postterm pregnancy, premature rupture of membranes, cervical laceration, forceps vaginal delivery, and shock (all P < .001). There was no difference in mortality between hysterectomy and UAE. After balancing demographic, maternal, and delivery risk factors, the odds of prolonged hospital stay were 0.38 times lower with UAE than hysterectomy (P < .001). CONCLUSIONS: Despite similar mortality and shorter hospital stays, UAE is used far less than hysterectomy in the management of severe PPH.

Validation of Hypertensive Disorders During Pregnancy: ICD-10 Codes in a High-burden Southeastern United States Hospital.

BACKGROUND: Identification of hypertensive disorders in pregnancy research often uses hospital International Classification of Diseases v. 10 (ICD-10) codes meant for billing purposes, which may introduce misclassification error relative to medical records. We estimated the validity of ICD-10 codes for hypertensive disorders during pregnancy overall and by subdiagnosis, compared with medical record diagnosis, in a Southeastern United States high disease burden hospital. METHODS: We linked medical record data with hospital discharge records for deliveries between 1 July 2016, and 30 June 2018, in an Atlanta, Georgia, public hospital. For any hypertensive disorder (with and without unspecified codes) and each subdiagnosis (hemolysis, elevated liver enzymes, and low platelet count [HELLP] syndrome, eclampsia, preeclampsia with and without severe features, chronic hypertension, superimposed preeclampsia, and gestational hypertension), we calculated positive predictive value (PPV), negative predictive value (NPV) sensitivity, and specificity for ICD-10 codes compared with medical record diagnoses (gold standard). RESULTS: Thirty-seven percent of 3,654 eligible pregnancies had a clinical diagnosis of any hypertensive disorder during pregnancy. Overall, ICD-10 codes identified medical record diagnoses well (PPV, NPV, specificity >90%; sensitivity >80%). PPV, NPV, and specificity were high for all subindicators (>80%). Sensitivity estimates were high for superimposed preeclampsia, chronic hypertension, and gestational hypertension (>80%); moderate for eclampsia (66.7%; 95% confidence interval [CI] = 22.3%, 95.7%), HELLP (75.0%; 95% CI = 50.9%, 91.3%), and preeclampsia with severe features (58.3%; 95% CI = 52.6%, 63.8%); and low for preeclampsia without severe features (3.2%; 95% CI, 1.4%, 6.2%). CONCLUSIONS: We provide bias parameters for future US-based studies of hypertensive outcomes during pregnancy in high-burden populations using hospital ICD-10 codes.

Validation of ICD-10 Codes for Gestational and Pregestational Diabetes During Pregnancy in a Large, Public Hospital.

BACKGROUND: The use of billing codes (ICD-10) to identify and track cases of gestational and pregestational diabetes during pregnancy is common in clinical quality improvement, research, and surveillance. However, specific diagnoses may be misclassified using ICD-10 codes, potentially biasing estimates. The goal of this study is to provide estimates of validation parameters (sensitivity, specificity, positive predictive value, and negative predictive value) for pregestational and gestational diabetes diagnosis using ICD-10 diagnosis codes compared with medical record abstraction at a large public hospital in Atlanta, Georgia. METHODS: This study includes 3,654 deliveries to Emory physicians at Grady Memorial Hospital in Atlanta, Georgia, between 2016 and 2018. We linked information abstracted from the medical record to ICD-10 diagnosis codes for gestational and pregestational diabetes during the delivery hospitalization. Using the medical record as the gold standard, we calculated sensitivity, specificity, positive predictive value, and negative predictive value for each. RESULTS: For both pregestational and gestational diabetes, ICD-10 codes had a high-negative predictive value (>99%, Table 3) and specificity (>99%). For pregestational diabetes, the sensitivity was 85.9% (95% CI = 78.8, 93.0) and positive predictive value 90.8% (95% CI = 85, 97). For gestational diabetes, the sensitivity was 95% (95% CI = 92, 98) and positive predictive value 86% (95% CI = 81, 90). CONCLUSIONS: In a large public hospital, ICD-10 codes accurately identified cases of pregestational and gestational diabetes with low numbers of false positives.

Hypertensive Disorders of Pregnancy, Cesarean Delivery, and Severe Maternal Morbidity in an Urban Safety-Net Population.

Hypertensive disorders of pregnancy (HDP) are a leading cause of severe maternal morbidity (SMM), yet mediation by cesarean delivery is largely unexplored. We investigated the association between HDP and SMM in a cohort of deliveries at a safety-net institution in Atlanta, Georgia, during 2016-2018. Using multivariable generalized linear models, we estimated adjusted risk differences, adjusted risk ratios, and 95% confidence intervals for the association between HDP and SMM. We examined interactions with cesarean delivery and used mediation analysis with 4-way decomposition to estimate excess relative risks. Among 3,723 deliveries, the SMM rate for women with and without HDP was 124.4 per 1,000 and 52.0 per 1,000, respectively. The adjusted risk ratio for the total effect of HDP on SMM was 2.55 (95% confidence interval (CI): 2.15, 3.39). Approximately 55.2% (95% CI: 25.7, 68.5) of excess relative risk was due to neither interaction nor mediation, 24.9% (95% CI: 15.4, 50.0) was due to interaction between HDP and cesarean delivery, 9.6% (95% CI: 3.4, 15.2) was due to mediation, and 10.3% (95% CI: 5.4, 20.3) was due to mediation and interaction. HDP are a potentially modifiable risk factor for SMM; implementing evidence-based interventions for the prevention and treatment of HDP is critical for reducing SMM risk.

Severe cardiovascular morbidity in women with hypertensive diseases during delivery hospitalization.

BACKGROUND: Cardiovascular disease is the leading cause of pregnancy-related death in the United States. Identification of short-term indicators of cardiovascular morbidity has the potential to alter the course of this devastating disease among women. It has been established that hypertensive disorders of pregnancy are associated with increased risk of cardiovascular disease 10-30 years after delivery; however, little is known about the association of hypertensive disorders of pregnancy with cardiovascular morbidity during the delivery hospitalization. OBJECTIVE: We aimed to identify the immediate risk of cardiovascular morbidity during the delivery hospitalization among women who experienced a hypertensive disorder of pregnancy. MATERIALS AND METHODS: This retrospective cohort study of women, 15-55 years old with a singleton gestation between 2008 and 2012 in New York City, examined the risk of severe cardiovascular morbidity in women with hypertensive disorders of pregnancy compared with normotensive women during their delivery hospitalization. Women with a history of chronic hypertension, diabetes mellitus, or cardiovascular disease were excluded. Mortality and severe cardiovascular morbidity (myocardial infarction, cerebrovascular disease, acute heart failure, heart failure or arrest during labor or procedure, cardiomyopathy, cardiac arrest and ventricular fibrillation, or conversion of cardiac rhythm) during the delivery hospitalization were identified using birth certificates and discharge record coding. Using multivariable logistic regression, we assessed the association between hypertensive disorders of pregnancy and severe cardiovascular morbidity, adjusting for relevant sociodemographic and pregnancy-specific clinical risk factors. RESULTS: A total of 569,900 women met inclusion criteria. Of those women, 39,624 (6.9%) had a hypertensive disorder of pregnancy: 11,301 (1.9%) gestational hypertension; 16,117 (2.8%) preeclampsia without severe features; and 12,206 (2.1%) preeclampsia with severe features, of whom 319 (0.06%) had eclampsia. Among women with a hypertensive disorder of pregnancy, 431 experienced severe cardiovascular morbidity (10.9 per 1000 deliveries; 95% confidence interval, 9.9-11.9). Among normotensive women, 1780 women experienced severe cardiovascular morbidity (3.4 per 1000 deliveries; 95% confidence interval, 3.2-3.5). Compared with normotensive women, there was a progressively increased risk of cardiovascular morbidity with gestational hypertension (adjusted odds ratio, 1.18; 95% confidence interval, 0.92-1.52), preeclampsia without severe features (adjusted odds ratio, 1.96; 95% confidence interval, 1.66-2.32), preeclampsia with severe features (adjusted odds ratio, 3.46; 95% confidence interval, 2.99-4.00), and eclampsia (adjusted odds ratio, 12.46; 95% confidence interval, 7.69-20.22). Of the 39,624 women with hypertensive disorders of pregnancy, there were 15 maternal deaths, 14 of which involved 1 or more cases of severe cardiovascular morbidity. CONCLUSION: Hypertensive disorders of pregnancy, particularly preeclampsia with severe features and eclampsia, are significantly associated with cardiovascular morbidity during the delivery hospitalization. Increased vigilance, including diligent screening for cardiac pathology in patients with hypertensive disorders of pregnancy, may lead to decreased morbidity for mothers.

Postpartum healthcare expenditures for commercially insured deliveries with and without severe maternal morbidity.

BACKGROUND: Although severe maternal morbidity is associated with adverse health outcomes in the year after delivery, patterns of healthcare use beyond the 6-week postpartum period have not been well documented. OBJECTIVE: This study aimed to estimate healthcare utilization and expenditures for deliveries with and without severe maternal morbidity in the 12 months following delivery among commercially insured patients. STUDY DESIGN: Using data from the 2016 to 2018 IBM Marketscan Commercial Claims and Encounters Research Databases, we identified deliveries to individuals 15 to 49 years of age who were continuously enrolled in noncapitated health plans for 12 months after delivery discharge. We used multivariable generalized linear models to estimate adjusted mean 12-month medical expenditures and 95% confidence intervals for deliveries with and without severe maternal morbidity, accounting for region, health plan type, delivery method, and obstetrical comorbidities. We estimated expenditures associated with inpatient admissions, nonemergency outpatient visits, outpatient emergency department visits, and outpatient pharmaceutical claims. RESULTS: We identified 366,282 deliveries without severe maternal morbidity and 3976 deliveries (10.7 per 1000) with severe maternal morbidity. Adjusted mean total medical expenditures for deliveries with severe maternal morbidity were 43% higher in the 12 months after discharge than deliveries without severe maternal morbidity ($5320 vs $3041; difference $2278; 95% confidence interval, $1591-$2965). Adjusted mean expenditures for readmissions and nonemergency outpatient visits during the 12-month postpartum period were 61% and 39% higher, respectively, for deliveries with severe maternal morbidity compared with deliveries without severe maternal morbidity. Among deliveries with severe maternal morbidity, adjusted mean total costs were highest for patients living in the western region ($7831; 95% confidence interval, $5518-$10,144) and those having a primary cesarean ($7647; 95% confidence interval, $6323-$8970). CONCLUSION: Severe maternal morbidity at delivery is associated with increased healthcare use and expenditures in the year after delivery. These estimates can inform planning of severe maternal morbidity prevention efforts.

Timely treatment of severe hypertension and risk of severe maternal morbidity at an urban hospital.

BACKGROUND: Hypertensive disorders of pregnancy have been identified as a leading contributor to severe maternal morbidity and mortality. Pregnant persons with hypertensive disorders who develop severe hypertension at delivery admission have been shown to experience higher rates of severe maternal morbidity relative to those without severe hypertension. Current guidelines recommend prompt treatment of severe hypertension given known associated maternal and fetal risks; however, only 1 previous study has described an association between timeliness of antihypertensive therapy and risk of severe maternal morbidity. OBJECTIVE: This study aimed to characterize how development of severe intrapartum hypertension and its timely treatment affect the risk of severe maternal morbidity. STUDY DESIGN: We conducted a population cohort study of deliveries with and without hypertensive disorders of pregnancy at a single urban hospital between 2016 and 2018. Among deliveries of persons with hypertensive disorders of pregnancy, we identified those with persistent severe hypertension (defined as blood pressure ≥160/105 mm Hg sustained over ≥15 minutes) and further classified individuals with severe hypertension as having received timely (within 60 minutes) or delayed treatment. Severe maternal morbidity was identified using a composite measure developed by the Centers for Disease Control and Prevention. We calculated overall and indicator-specific rates of severe maternal morbidity for 4 categories of deliveries: without hypertensive disorder of pregnancy, with hypertensive disorder of pregnancy without severe hypertension, with severe hypertension and timely treatment, and with severe hypertension and delayed treatment. We assessed the association between hypertensive disorder of pregnancy, severe hypertension, timeliness of treatment, and severe maternal morbidity using multivariable robust Poisson regression, adjusting for demographic and clinical characteristics. RESULTS: Of 3723 delivery hospitalizations within the study time frame, 32.3% (1204/3723) were complicated by presence of a hypertensive disorder without severe hypertension and 5.7% (211/3723) by presence of a hypertensive disorder with severe hypertension. Among those with severe hypertension, 48.8% (103/211) received timely treatment. Compared with deliveries not complicated by a hypertensive disorder, severe maternal morbidity risk was increased for hypertensive disorder of pregnancy without severe hypertension (124.4/1000 vs 52.0/1000; adjusted risk ratio, 1.84; 95% confidence interval, 1.41-2.40), severe hypertension with timely treatment (233.0/1000; adjusted risk ratio, 3.81; 95% confidence interval, 2.45-5.92), and severe hypertension with delayed treatment (305.6/1000; adjusted risk ratio, 5.38; 95% confidence interval, 3.75-7.73). CONCLUSION: Patients with hypertensive disorders of pregnancy are at an elevated risk of severe maternal morbidity, and development of severe hypertension further increases this risk. Timely antihypertensive treatment is associated with lower risk of severe maternal morbidity among those with severe hypertension. These findings emphasize the importance of provider education and quality improvement efforts aimed at expediting treatment of severe hypertension.

Severe Maternal Morbidity and Postpartum Readmission Through 1 Year.

OBJECTIVE: To conduct a cohort study to estimate risk for readmission through 1 year postpartum and the most common readmission diagnoses for individuals with and without severe maternal morbidity (SMM) at delivery. METHODS: Using national health care claims data from IBM MarketScan Commercial Research Databases (now known as Merative), we identified all delivery hospitalizations for continuously enrolled individuals 15-49 years of age that occurred between January 1, 2016, and December 31, 2018. Severe maternal morbidity at delivery was identified using diagnosis and procedure codes. Individuals were followed for 365 days after delivery discharge, and cumulative readmission rates were calculated for up to 42 days, up to 90 days, up to 180 days, and up to 365 days. We used multivariable generalized linear models to estimate adjusted relative risks (aRR), adjusted risk differences, and 95% CIs for the association between readmission and SMM at each of the timepoints. RESULTS: The study population included 459,872 deliveries; 5,146 (1.1%) individuals had SMM during the delivery hospitalization, and 11,603 (2.5%) were readmitted within 365 days. The cumulative incidence of readmission was higher in individuals with SMM than those without at all timepoints (within 42 days: 3.5% vs 1.2%, aRR 1.44, 95% CI 1.23-1.68; within 90 days: 4.1% vs 1.4%, aRR 1.46, 95% CI 1.26-1.69); within 180 days: 5.0% vs 1.8%, aRR 1.48, 95% CI 1.30-1.69; within 365 days: 6.4% vs 2.5%, aRR 1.44, 95% CI 1.28-1.61). Sepsis and hypertensive disorders were the most common reason for readmission within 42 and 365 days for individuals with SMM (35.2% and 25.8%, respectively). CONCLUSION: Severe maternal morbidity at delivery was associated with increased risk for readmission throughout the year after delivery, a finding that underscores the need for heightened awareness of risk for complications beyond the traditional 6-week postpartum period.

Interpretable machine learning to predict adverse perinatal outcomes: examining marginal predictive value of risk factors during pregnancy.

BACKGROUND: The timely identification of nulliparas at high risk of adverse fetal and neonatal outcomes during pregnancy is crucial for initiating clinical interventions to prevent perinatal complications. Although machine learning methods have been applied to predict preterm birth and other pregnancy complications, many models do not provide explanations of their predictions, limiting the clinical use of the model. OBJECTIVE: This study aimed to develop interpretable prediction models for a composite adverse perinatal outcome (stillbirth, neonatal death, estimated Combined Apgar score of <10, or preterm birth) at different points in time during the pregnancy and to evaluate the marginal predictive value of individual predictors in the context of a machine learning model. STUDY DESIGN: This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be data, a prospective cohort study in which 10,038 nulliparous pregnant individuals with singleton pregnancies were enrolled. Here, interpretable prediction models were developed using L1-regularized logistic regression for adverse perinatal outcomes using data available at 3 study visits during the pregnancy (visit 1: 6 0/7 to 13 6/7 weeks of gestation; visit 2: 16 0/7 to 21 6/7 weeks of gestation; visit 3: 22 0/7 to 29 6/7 weeks of gestation). We identified the important predictors for each model using SHapley Additive exPlanations, a model-agnostic method of computing explanations of model predictions, and evaluated the marginal predictive value of each predictor using the DeLong test. RESULTS: Our interpretable machine learning model had an area under the receiver operating characteristic curves of 0.617 (95% confidence interval, 0.595-0.639; all predictor variables at visit 1), 0.652 (95% confidence interval, 0.631-0.673; all predictor variables at visit 2), and 0.673 (95% confidence interval, 0.651-0.694; all predictor variables at visit 3). For all visits, the placental biomarker inhibin A was a valuable predictor, as including inhibin A resulted in better performance in predicting adverse perinatal outcomes (P<.001, all visits). At visit 1, endoglin was also a valuable predictor (P<.001). At visit 2, free beta human chorionic gonadotropin (P=.001) and uterine artery pulsatility index (P=.023) were also valuable predictors. At visit 3, cervical length was also a valuable predictor (P<.001). CONCLUSION: Despite various advances in predictive modeling in obstetrics, the accurate prediction of adverse perinatal outcomes remains difficult. Interpretable machine learning can help clinicians understand how predictions are made, but barriers exist to the widespread clinical adoption of machine learning models for adverse perinatal outcomes. A better understanding of the evolution of risk factors for adverse perinatal outcomes throughout pregnancy is necessary for the development of effective interventions.

Social Determinants of Health Needs and Perinatal Risk in Socially Vulnerable Pregnant Patients.

OBJECTIVES: To understand perinatal risks associated with social needs in pregnancy Methods. Multivariable log-binomial regression analyses adjusting for age, parity, and insurance were used to evaluate the relationship between any social need (e.g., housing, transportation, food, and intimate partner violence) and adverse perinatal outcomes (stillbirth, prematurity, maternal morbidity) in a cohort of English and Spanish-speaking patients who obtained prenatal care and birthed at our institution during a one-year period. RESULTS: Of 2,435 patients, 1,608 (66%) completed social needs screening at least once during prenatal care. The cohort was predominantly non-Hispanic Black (1,294, 80%) and publicly insured (1,395, 87%). Having one or more social need was associated with three-fold increased risk of stillbirth (aRR 3.35, 95%CI 1.31,8.6) and 14% reduction in postpartum care attendance (aRR 0.86, 95%CI 0.78-0.95) and was highest in individuals reporting transportation needs. CONCLUSIONS: Social needs during pregnancy were associated with increased risk of stillbirth.

Demographic and Clinical Predictors of Postpartum Blood Pressure Screening Attendance.

Background: Hypertensive disorders of pregnancy (HDP) cause substantial preventable maternal morbidity and mortality. Postpartum hypertension that worsens after women are discharged is particularly dangerous, as it can go undiagnosed and cause complications. The American College of Obstetricians and Gynecologists recommends women with HDP undergo blood pressure (BP) screening 7-10 days after delivery to detect postpartum hypertension. This study aimed to describe predictors of postpartum BP screening attendance among a high-risk safety-net population in Atlanta, Georgia. Materials and Methods: We conducted a population-based cohort study of pregnant women who delivered at a large public hospital in Atlanta between July 1, 2016, and June 30, 2018. We manually abstracted demographic and clinical data from electronic medical records and used multivariable log binomial regression to estimate adjusted risk ratios (aRRs) and 95% confidence intervals (95% CIs) for associations with BP screening attendance. Results: Of 1260 women diagnosed with HDP, 13.7% attended a BP screening visit within 10 days of delivery. Women with preeclampsia with severe features were more likely to attend a BP visit than women with gestational hypertension (aRR 2.10, 95% CI 1.35-3.27). Rates of BP screening attendance were lower for women with inadequate (aRR 0.42, 95% CI 0.26-0.67) and intermediate (aRR 0.40, 95% CI 0.21-0.74) prenatal care utilization relative to women with adequate utilization. Conclusions: Among a high-risk safety-net population with HDP, most women did not attend a BP screening visit within 10 days of delivery. Addressing this gap requires further research and creative solutions to address barriers at the individual, provider, and system levels.

Delivery outcomes after induction of labor among women with hypertensive disorders of pregnancy.

OBJECTIVE: Induction of labor is known to be safe and highly effective in low-risk women. However, only limited research considers the relative success rates of induction of labor among women with one or more obstetric comorbidities. Our objective was to determine if the risk of cesarean delivery after induction of labor (IOL) is increased in women with a spectrum of hypertensive disorders of pregnancy compared to women with normotensive pregnancies. STUDY DESIGN: We analyzed data from 1842 women undergoing IOL occurring at Grady Memorial Hospital in Atlanta, Georgia 2016-2018. We used multivariable log binomial models to estimate unadjusted and adjusted risk ratios (aRR) describing the association between hypertensive disorder diagnosis (preeclampsia with or without severe features, gestational hypertension, and chronic hypertension) and cesarean delivery, adjusting for demographics, pre-pregnancy conditions, and gestational age at delivery. RESULTS: Overall, 44% (n = 808) of women in our study were diagnosed with any hypertensive disorder. Among women with hypertensive disorders, 74% had a successful vaginal delivery after IOL as compared to 82% of women without a hypertensive disorder. In the fully adjusted model, women with preeclampsia with severe features (aRR: 1.6, 95% CI: (1.3, 2.0)) and chronic hypertension had the largest risk for cesarean delivery (aRR 1.3, 95% CI: 0.9, 1.7)) compared with women with a normotensive pregnancy. CONCLUSION: Our study suggests that while patients with certain hypertensive diagnoses may be at increased risk for cesarean delivery following IOL, most patients with hypertensive disorders were still able to undergo a successful vaginal delivery following IOL.

Severe maternal morbidity and mortality during delivery hospitalization of class I, II, III, and super obese women.

BACKGROUND: Previous studies show that obesity predisposes patients to higher risks of adverse pregnancy outcomes. Data on the relationship between increasing degrees of obesity and risks of severe maternal morbidity, including mortality, are limited. OBJECTIVE: We examined the association of increasing classes of obesity, especially super obesity, with the risk of severe maternal morbidity and mortality at the time of delivery hospitalization. STUDY DESIGN: Using New York City linked birth certificates and hospital discharge data, we conducted a retrospective cohort study. This study identified delivery hospitalizations for singleton, live births in 2008-2012. Women were classified as having obesity (class I, II, III, or super obesity), as opposed to normal weight or overweight, based on prepregnancy body mass index. Cases of severe maternal morbidity were identified based on International Classification of Diseases, Ninth Revision diagnosis and procedure codes according to Centers for Disease Control and Prevention criteria. Multivariable logistic regression was used to evaluate the association between obesity classes and severe maternal morbidity, adjusting for maternal sociodemographic characteristics. RESULTS: During 2008-2012, there were 570,997 live singleton births with available information on prepregnancy body mass index that met all inclusion criteria. After adjusting for maternal characteristics, women with class II (adjusted odds ratio, 1.14; 95% confidence interval, 1.05-1.23), class III (adjusted odds ratio, 1.34; 95% confidence interval, 1.21-1.49), and super obesity (adjusted odds ratio, 1.99; 95% confidence interval, 1.57-2.54) were all significantly more likely to have severe maternal morbidity than normal and overweight women. Super obesity was associated with specific severe maternal morbidity indicators, including renal failure, air and thrombotic embolism, blood transfusion, heart failure, and the need for mechanical ventilation. CONCLUSION: There is a significant dose-response relationship between increasing obesity class and the risk of severe maternal morbidity at delivery hospitalization. The risks of severe maternal morbidity are highest for women with super obesity. Given that this is a modifiable risk factor, women with prepregnancy obesity should be counseled on the specific risks associated with pregnancy before conception to optimize their pregnancy outcomes.

Gestational Weight Gain and Severe Maternal Morbidity at Delivery Hospitalization.

OBJECTIVE: To examine whether women who varied from recommended gestational weight gain guidelines by the Institute of Medicine (IOM, now known as the National Academy of Medicine) were at increased risk of severe maternal morbidity during delivery hospitalization compared with those whose weight gain remained within guidelines. METHODS: We conducted a retrospective cohort study using linked 2008-2012 New York City discharge and birth certificate data sets. Cases of severe maternal morbidity were identified using International Classification of Diseases, 9th Revision, Clinical Modification codes based on the Centers for Disease Control and Prevention criteria, which consists of 21 indicators of possible life-threatening diagnoses, life-saving procedures, or death. Multivariable logistic regression was used to evaluate the association between gestational weight gain categories based on prepregnancy body mass index (BMI) and severe maternal morbidity adjusting for maternal demographics and socioeconomic status. The analysis was stratified by prepregnancy BMI categories. RESULTS: During 2008-2012, there were 515,148 term singleton live births in New York City with prepregnancy weight and gestational weight gain information. In 24.8%, 35.1%, 32.1%, and 8.0% of these births, women gained below, within, 1-19 lbs above, and 20 lbs or more above the IOM guidelines, respectively. After adjusting for maternal demographic and socioeconomic characteristics, women who had gestational weight gain 1-19 lbs above (adjusted odds ratio [AOR] 1.08, 95% CI 1.02-1.13) or 20 lbs or more above the IOM recommendations (AOR 1.21, 95% CI 1.12-1.31) had higher odds of overall severe maternal morbidity compared with women who gained within guidelines. Although the increased odds ratios (ORs) were statistically significant, this only resulted in an absolute rate increase of 2.1 and 6 cases of severe maternal morbidity per 1,000 deliveries for those who gained 1-19 and 20 lbs or more above recommendations, respectively. Women with gestational weight gain 20 lbs or more above recommendations had significantly higher ORs of eclampsia, heart failure during a procedure, pulmonary edema or acute heart failure, transfusion, and ventilation. CONCLUSION: Women whose gestational weight gain is in excess of IOM guidelines are at increased risk of severe maternal morbidity, although their absolute risks remain low.

Pregnancy-Associated Deaths in Rural, Nonrural, and Metropolitan Areas of Georgia.

OBJECTIVE: To characterize pregnancy-associated deaths and examine the relationship between area of residence and pregnancy-associated deaths and pregnancy-related mortality ratios in Georgia from 2010 to 2012. METHODS: The cohort of pregnancy-associated deaths was reviewed and categorized as pregnancy-related or resulting from other medical conditions not related to pregnancy, suicide, drug toxicity, homicide, or motor vehicle accident. Georgia Online Analytical Statistical Information System data were used to calculate pregnancy-related mortality ratio by rural, nonrural, and metropolitan Atlanta area and by race. Causes of death and pregnancy-related mortality ratio were compared by area of residence and race using χ tests; a P value <.05 was considered significant. RESULTS: There were 262 pregnancy-associated deaths; 40.1% (n=105) were pregnancy-related. The 2010-2012 pregnancy-related mortality ratio was 26.5 per 100,000 live births and the pregnancy-related mortality ratio did not differ statistically among rural (27.1), nonrural (24.4), and metropolitan Atlanta (27.7) areas (P=.845). Most pregnancy-related deaths were the result of hemorrhage and cardiovascular factors. In aggregate, the pregnancy-related mortality ratio for black women was 49.5 compared with 14.3 for white women (P<.001). The gap in pregnancy-related mortality ratio between black and white women was highest for metropolitan Atlanta (51.6 compared with 12.4, P<.001), less in nonrural areas (50.3 compared with 12.0, P<.001), and comparable in rural areas (39.4 compared with 22.4, P=.281). CONCLUSION: Although the pregnancy-related mortality ratio was similar for rural, nonrural, and metropolitan Atlanta areas, it was significantly higher for black compared with white women living outside of rural areas.