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

Hypertension subtypes and adverse maternal and perinatal outcomes - a retrospective population-based cohort study

BACKGROUND

This study aims to examine risk of adverse pregnancy outcomes and mothers' characteristics in patients with chronic hypertension, gestational hypertension and preeclampsia.

METHODS

The study included all births born from women aged 15-45 years, in Lleida, Spain from 2012 to 2018. Pregnancy outcomes were retrieved by regional administrative databases. Logistic regression analysis was used to calculate adjusted odds ratios (OR) (OR 95% CI) for maternal characteristics or neonatal outcomes.

RESULTS

Among 17,177 pregnant women, different types of hypertension present varying risks for both the mother and fetus. There is an increased risk of cesarean section in patients with preeclampsia (OR 2.04, 95% CI: 1.43-2.88). For the newborn, a higher risk of preterm birth is associated with maternal chronic hypertension (OR 3.09, 95% CI: 1.91-4.83) and preeclampsia (OR 5.07, 95% CI: 3.28-7.65). Additionally, there is a higher risk of low birth weight in cases of maternal chronic hypertension (OR 3.2, 95% CI: 2.04-4.88), preeclampsia (OR 5.07, 95% CI: 3.34-7.52), and gestational hypertension (OR 2.72, 95% CI: 1.49-4.68). Furthermore, only newborns of patients with preeclampsia had a higher risk of an Apgar score lower than 7 in the first minute (OR 2.95, 95% CI: 1.45-5.38).

CONCLUSIONS

In the study population adjusted for body weight, the different types of hypertension represent different risks in the mother and foetus. These complications were mostly associated with preeclampsia.

Planning for the forgotten fourth trimester of pregnancy: A parallel group randomized control trial to test a postpartum planning intervention vs. standard prenatal care

BACKGROUND

Black and brown birthing people experience persistent disparities in adverse maternal health outcomes, partially due to inadequate perinatal care. The goal of this study is to design and evaluate a patient-centered intervention for obstetric patients with one or more cardiometabolic risk factors for severe maternal morbidity [gestational diabetes, diabetes mellitus, hypertensive disorders of pregnancy (chronic hypertension, preeclampsia, eclampsia, or gestational hypertension), or preconception obesity (BMI > 30)] to promote postpartum visit attendance.

METHODS

To address identified unmet needs for postpartum support and barriers to postpartum care, we developed 20 thematic postpartum planning modules, each with corresponding patient educational materials, community resources, care coordination protocols, and clinician support tools (decision aids, electronic medical record prompts and fields). During prenatal care encounters, a research coordinator delivers the educational content (in English or Spanish), facilitates the participant's planning and shared decision-making, provides the participant with resources, and documents decisions in the electronic medical record. We will randomize 320 eligible patients with a 1:1 ratio to the intervention or standard prenatal care and evaluate the impact on postpartum visit attendance at 4-12 weeks and secondary outcomes (postpartum mental health, perceived future maternal and cardiometabolic risk, contraceptive use, primary care use, readmission, and patient satisfaction with care).

DISCUSSION

Through engagement with patients and community stakeholders, we developed a guideline-based, locally tailored intervention to address drivers of engagement with postpartum care for high-risk obstetric patients. If demonstrated to be effective, the educational materials and electronic medical record based-tool can be adapted to other settings.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.gov (NCT05430815) on June 23, 2022.

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.

Association of Postpartum Mental Illness Diagnoses with Severe Maternal Morbidity

Background: This study aimed to determine whether birthing people who experience severe maternal morbidity (SMM) are more likely to be diagnosed with a postpartum mental illness. Materials and Methods: Using the Massachusetts All Payer Claims Database, this study used modified Poisson regression analysis to assess the association of SMM with mental illness diagnosis during the postpartum year, accounting for prenatal mental illness diagnoses and other patient characteristics. Results: There were 128,161 deliveries identified, with 55.0% covered by Medicaid. Of these, 3.1% experienced SMM during pregnancy and/or delivery hospitalization, and 20.1% had a mental illness diagnosis within 1 year postpartum. In adjusted regression analyses, individuals with SMM had a 10.6% increased risk of having any mental illness diagnosis compared to individuals without SMM, primarily due to an increased risk of a depression or post-traumatic stress disorder diagnosis among people with SMM than those without SMM. Conclusions: Individuals who experienced SMM had a higher risk of a mental illness diagnosis in the postpartum year. Given increases in SMM in the United States in recent decades, policies to mitigate mental health sequelae of SMM are urgently needed.

Severe Maternal Morbidity among Low-Income Patients with Hypertensive Disorders of Pregnancy

OBJECTIVE

Hypertensive disorders of pregnancy (HDP) contribute significantly to the development of severe maternal morbidities (SMM), particularly among low-income women. The purpose of the study was to explore the relationship between maternal characteristics and SMM, and to investigate if differences in SMM exist among patients with HDP diagnosis.

STUDY DESIGN

This study utilized 2017 Alabama Medicaid administrative claims. SMM diagnoses were captured using the Centers for Disease Control and Prevention's classification by International Classification of Diseases codes. Maternal characteristics and frequencies were compared using Chi-square and Cramer's V statistics. Logistic regression analyses were conducted to examine multivariable relationships between maternal characteristics and SMM among patients with HDP diagnosis. Odds ratios and 95% confidence intervals (CIs) were used to estimate risk.

RESULTS

A higher proportion of patients experiencing SMM were >34 years old, Black, Medicaid for Low-Income Families eligible, lived in a county with greater Medicaid enrollment, and entered prenatal care (PNC) in the first trimester compared with those without SMM. Almost half of patients (46.2%) with SMM had a HDP diagnosis. After controlling for maternal characteristics, HDP, maternal age, county Medicaid enrollment, and trimester PNC entry were not associated with SMM risk. However, Black patients with HDP were at increased risk for SMM compared with White patients with HDP when other factors were taken into account (adjusted odds ratio [aOR] = 1.37, 95% CI: 1.11-1.69). Patients with HDP and SMM were more likely to have a prenatal hospitalization (aOR = 1.45, 95% CI: 1.20-1.76), emergency visit (aOR = 1.30, 95% CI: 1.07-1.57), and postpartum cardiovascular prescription (aOR = 2.43, 95% CI: 1.95-3.04).

CONCLUSION

Rates of SMM differed by age, race, Medicaid income eligibility, and county Medicaid enrollment but were highest among patients with clinical comorbidities, especially HDP. However, among patients with HDP, Black patients had an elevated risk of severe morbidity even after controlling for other characteristics.

KEY POINTS

· Patients with SMM were more likely to have a HDP diagnosis.. · Among those with HDP, Black patients had elevated risk of SMM.. · Differences in care delivery did not explain SMM disparities..

Antihypertensive Medication Use before and during Pregnancy and the Risk of Severe Maternal Morbidity in Individuals with Prepregnancy Hypertension

OBJECTIVE

Our objective is to examine severe maternal morbidity (SMM) and patterns of antihypertensive medication use before and during pregnancy among individuals with chronic hypertension.

STUDY DESIGN

We examined 11,759 pregnancies resulting in a live birth or stillbirth to individuals with chronic hypertension and one or more antihypertensive prescription 6 months before pregnancy (Optum, 2007-17). We examined whether study outcomes were associated with the use of medication as compared to no use during pregnancy. In addition, patterns of medication use based on the Food and Drug Administration guidance and literature were evaluated. Medication use was divided into prepregnancy and during pregnancy use and classified as pregnancy recommended (PR) or not pregnancy recommended (nPR) or no medication use. SMM was defined per the Centers for Disease Control and Prevention definition of 21 indicators. Risk ratios (RR) reflecting the association of SMM with the use of antihypertensive medications were computed using modified Poisson regression with robust standard errors and adjusted for maternal age, education, and birth year.

RESULTS

Overall, 83% of individuals filled an antihypertensive prescription during pregnancy and 6.3% experienced SMM. The majority of individuals with a prescription prior to pregnancy had a prescription for the same medication in pregnancy. Individuals with any versus no medication use in pregnancy had increased adjusted RR (aRR) of SMM (1.18, 95% confidence interval [CI]: 0.96-1.44). Compared to the use of PR medications before and during pregnancy, aRRs were 1.42 (95% CI: 1.18-1.69, 12.4% of sample) for nPR use before and during pregnancy, 1.52 (1.23-1.86; 12.4%) for nPR (before) and PR (during) use, and 2.67 (1.73-4.15) for PR and nPR use. Patterns with no medication use during pregnancy were not statistically significant.

CONCLUSION

Pattern of antihypertensive medication use before and during pregnancy may be associated with an elevated risk of SMM. Further research is required to elucidate whether this association is related to the severity of hypertension, medication effectiveness, or suboptimal quality of care.

KEY POINTS

· Individuals with any medication use compared to no medication use in pregnancy had an increased risk of SMM.. · Specific medication use patterns were associated with an elevated risk of SMM.. · Pattern of antihypertensive medication use before and during pregnancy may be associated with an increased risk of SMM..

Mediating processes underlying the associations between maternal obesity and the likelihood of cesarean birth

BACKGROUND

Pregnant women with obesity are more likely to experience cesarean birth compared to women without obesity. Yet, little is known about the underlying mechanisms. The objective of this study was therefore to evaluate how mediators contribute to the association between obesity and prelabor/intrapartum cesarean birth.

METHODS

We retrospectively analyzed Swiss cohort data from 394,812 singleton, cephalic deliveries between 2005 and 2020. Obesity (BMI ≥ 30 kg/m2 ) was defined as the exposure and prelabor or intrapartum cesarean birth as the outcomes. Hypothesized mediators included gestational comorbidities, large-for-gestational-age infant, pregnancy duration >410/7 weeks, slower labor progress, labor induction, and history of cesarean birth. We performed path analyses using generalized structural equation modeling and assessed mediation by a counterfactual approach.

RESULTS

Women with obesity had a cesarean birth rate of 39.36% vs. 24.12% in women without obesity. The path models mainly showed positive direct and indirect associations between obesity and cesarean birth. In the total sample, the mediation models explained up to 39.47% (95% CI 36.92-42.02) of the association between obesity and cesarean birth, and up to 57.13% (95% CI 54.10-60.16) when including history of cesarean birth as mediator in multiparous women. Slower labor progress and history of cesarean birth were found to be the most clinically significant mediators.

CONCLUSIONS

This study provides empirical insights into how obesity may increase cesarean birth rates through mediating processes. Particularly allowing for a slower labor progress in women with obesity might reduce cesarean birth rates and prevent subsequent repeat cesarean births in multiparous women.

Improving obstetric and perinatal outcomes with a remote patient monitoring program for hypertension in a large integrated care system

OBJECTIVE

To determine the effect of a remote patient monitoring program for hypertension (RPM HTN) in patients diagnosed with hypertensive disorders of pregnancy.

STUDY DESIGN

We used a matched retrospective cohort design to evaluate differences in obstetric and perinatal outcomes using data from electronic medical records. Patients enrolled in RPM HTN between November 1, 2019, and October 31, 2021, who delivered a pregnancy at ≥20 weeks gestation were compared to a cohort of patients matched by age, race, HTN and diabetes status, who delivered in the 48-month period before implementation of RPM HTN.

RESULTS

1030 patients were enrolled in RPM HTN and 937 were matched to historical controls. Five hundred and seventeen (50.2 %) were enrolled in the antepartum period and 513 (49.8 %) were enrolled postpartum. Patients in the RPM HTN cohort were more likely to have a post-hospital discharge blood pressure (BP) measured within the first 20 days after delivery (RR 1.56, 95 % CI: 1.47-1.65: p < 0.01) and were more likely to have that BP be normal (RR 1.43, 95 % CI: 1.31-1.55: p = 0.05). They were also more likely to be taking antihypertensives postpartum (RR 1.27, 95 % CI: 1.15-1.40; p < 0.01) and to be evaluated by an obstetric clinician within 20 days of delivery (RR 1.50, 95 % CI 1.42-1.58; p < 0.01).

CONCLUSIONS

A remote HTN monitoring program for 937 obstetric patients was associated with improved BP monitoring, better postpartum BP control, and improved linkages to clinician care after delivery, when compared to historical controls.

Decomposing the Black-White Racial Disparity in Severe Maternal Morbidity Risk: The Role of Hypertensive Disorders of Pregnancy

BACKGROUND

To our knowledge, no studies have explicitly studied the role of hypertensive disorders of pregnancy (HDP) in racial disparities in severe maternal morbidity (SMM).

METHODS

Using causal mediation models, we estimated the proportion of the non-Hispanic (NH) Black-White racial disparity in risk of SMM that is explained through the pathway of HDP. We linked 2006-2019 Georgia hospital discharge records with vital statistics birth and fetal death records for NH Black and NH White birthing persons. We used G-estimation of a structural nested mean model to decompose the absolute racial disparity in the incidence of SMM into pathways operating through HDP.

RESULTS

NH Black birthing people experienced an excess 56 SMM events (95% confidence interval [CI] = 52, 59) per 10,000 delivery hospitalizations compared with NH White birthing people. If counterfactual disparity measure estimation assumptions hold, the estimated absolute disparity remaining after blocking the causal pathways through HDP was 41 SMM events per 10,000 deliveries (95% CI = 38, 44), suggesting that 26% (95% CI = 12, 40) of the absolute racial disparity would be eliminated if there was no contribution of HDP to SMM risk.

CONCLUSION

Our results are consistent with the hypothesis that intervening to prevent HDP is an important (yet incomplete) pathway for reducing the excess risk among NH Black pregnancies compared with NH White pregnancies.

"We adjusted for race": now what? A systematic review of utilization and reporting of race in American Journal of Epidemiology and Epidemiology, 2020-2021

Race is a social construct, commonly used in epidemiologic research to adjust for confounding. However, adjustment of race may mask racial disparities, thereby perpetuating structural racism. We conducted a systematic review of articles published in Epidemiology and American Journal of Epidemiology between 2020 and 2021 to (1) understand how race, ethnicity, and similar social constructs were operationalized, used, and reported; and (2) characterize good and poor practices of utilization and reporting of race data on the basis of the extent to which they reveal or mask systemic racism. Original research articles were considered for full review and data extraction if race data were used in the study analysis. We extracted how race was categorized, used-as a descriptor, confounder, or for effect measure modification (EMM)-and reported if the authors discussed racial disparities and systemic bias-related mechanisms responsible for perpetuating the disparities. Of the 561 articles, 299 had race data available and 192 (34.2%) used race data in analyses. Among the 160 US-based studies, 81 different racial categorizations were used. Race was most often used as a confounder (52%), followed by effect measure modifier (33%), and descriptive variable (12%). Fewer than 1 in 4 articles (22.9%) exhibited good practices (EMM along with discussing disparities and mechanisms), 63.5% of the articles exhibited poor practices (confounding only or not discussing mechanisms), and 13.5% were considered neither poor nor good practices. We discuss implications and provide 13 recommendations for operationalization, utilization, and reporting of race in epidemiologic and public health research.

Types and timing of trauma exposure across the life course and maternal hypertension

Objective

To estimate associations between types and timing (first occurrence and time since) of trauma exposure and hypertension experienced during pregnancy in a safety-net hospital in Atlanta, Georgia.

Methods

Participants completed a 14-item trauma screener. We linked that information to data from the medical record on hypertension (inclusive of chronic hypertension, gestational hypertension, or preeclampsia). We fit logistic regression models and used the estimates to calculate risk ratios for each trauma type and each critical window (0-9 years, 10-19, and 20+). We fit unadjusted models and adjusted for age, parity, and education.

Results

We included 704 individuals with a delivery within 12 months of screening. The majority (94%, 661) reported at least one traumatic event, most commonly witnessing violence (79.4%). Overall, 18% experienced gestational hypertension, 10.8% chronic hypertension, and 11.9% preeclampsia. Among individuals who reported trauma, 31.5% screened positive for probable posttraumatic stress disorder and 30.9% for probable depression compared to 0 and 2.3% among those without reported trauma. No trauma type (violence, witnessing violence, non-interpersonal, or sexual assault) was associated with increased hypertensive risk, regardless of timing. Similarly, time between trauma and delivery (0-3 years, 3-10 years, 10+ years) was not associated with increased hypertensive risk.

Conclusions

In this sample with a high trauma and hypertension burden, trauma was not associated with elevated risk of hypertension during pregnancy, despite a high burden of PTSD and depressive symptoms among people with trauma exposure. Future research should consider how community-level exposure may modify the impact of trauma on adverse pregnancy outcomes.

Establishment and Validation of a Machine Learning-Based Prediction Model for Termination of Pregnancy via Cesarean Section

Objective

This study aimed to investigate the risk factors of cesarean section and establish a prediction model for cesarean section based on the characteristics of pregnant women.

Methods

The clinical characteristics of 2552 singleton pregnant women who delivered a live baby between January 2020 and December 2021 were retrospectively reviewed. They were divided into vaginal delivery group (n = 1850) and cesarean section group (n = 702). These subjects were divided into training set (2020.1-2021.6) and validation set (2021.7-2021.12). In the training set, univariate analysis, Lasso regression, and Boruta were used to screen independent risk factors for cesarean section. Four models, including Logistic Regression (LR), K-Nearest Neighbor (KNN), Classification and Regression Tree (CART), and Random forest (RF), were established in the training set using K-fold cross validation, hyperparameter optimization, and random oversampling techniques. The best model was screened, and Sort graph of feature variables, univariate partial dependency profile, and Break Down profile were delineated. In the validation set, the confusion matrix parameters were calculated, and receiver operating characteristic curve (ROC), precision recall curve (PRC), calibration curve, and clinical decision curve analysis (DCA) were delineated.

Results

The risk factors of cesarean section included age and height of women, weight at delivery, weight gain, para, assisted reproduction, abnormal blood glucose during pregnancy, pregnancy hypertension, scarred uterus, premature rupture of membrane (PROM), placenta previa, fetal malposition, thrombocytopenia, floating fetal head, and labor analgesia. RF had the best performance among the four models, and the accuracy of confusion matrix parameters was 0.8956357. The Matthews correlation coefficient (MCC) was 0.753012. The area under ROC (AUC-ROC) was 0.9790787, and the area under PRC (AUC-PRC) was 0.957888.

Conclusion

RF prediction model for caesarean section has high discrimination performance, accuracy and consistency, and outstanding generalization ability.

Pregnancy outcomes in women with gestational hypertension and preeclampsia at Paropakar Maternity and Women's Hospital, Nepal: A retrospective study

INTRODUCTION

Gestational hypertension and preeclampsia are the most common types of hypertensive disorder in pregnancy and these conditions are associated with adverse maternal and fetal outcomes. This study aims to determine the differences in pregnancy outcomes in women with gestational hypertension and preeclampsia.

METHODS

A retrospective study was done at The Paropakar Maternity and Women's Hospital, a tertiary level hospital, in the Kathmandu, Nepal. Pregnant women who had given birth at the hospital between September 17 and December 18 of 2017 were included. Data were obtained from the non-digitalized hospital records. The adjusted odds ratio (AOR) and 95% confidence interval were computed using logistic regression analysis. Multivariable analysis of pregnancy outcomes (cesarean sections, low birth weight, and preterm birth) was adjusted for maternal age, parity, twin birth, gestational age, calcium supplementation, and maternal co-morbidity.

RESULTS

Preeclampsia was strongly associated with cesarean section compared to normal pregnancies (OR = 8.11, p<0.001). Whereas the odds of cesarean section among women with gestational hypertension was almost 2 times (OR = 1.89, p<0.001). Preterm birth was not significantly associated with gestational hypertension but was associated with preeclampsia (OR = 3.39, p<0.001). Gestational hypertension and preeclampsia were not associated with low birth weight.

CONCLUSION

In Nepal, women who develop preeclampsia seem at higher risk of having adverse pregnancy outcomes than women with gestational hypertension. These findings should be considered by national health authorities and other health organizations when setting new priorities to improve pregnancy outcomes.

Machine learning-based evaluation of application value of pulse wave parameter model in the diagnosis of hypertensive disorder in pregnancy

Hypertensive disorder in pregnancy (HDP) remains a major health burden, and it is associated with systemic cardiovascular adaptation. The pulse wave is an important basis for evaluating the status of the human cardiovascular system. This research aims to evaluate the application value of pulse waves in the diagnosis of hypertensive disorder in pregnancy.This research a retrospective study of pregnant women who attended prenatal care and labored at Beijing Haidian District Maternal and Child Health Hospital. We extracted maternal hemodynamic factors and measured the pulse wave of the pregnant women. We developed an HDP predictive model by using support vector machine algorithms at five-gestational-week stages.At five-gestational-week stages, the area under the receiver operating characteristic curve (AUC) of the predictive model with pulse wave parameters was higher than that of the predictive model with hemodynamic factors. The AUC values of the predictive model with pulse wave parameters were 0.77 (95% CI 0.64 to 0.9), 0.83 (95% CI 0.77 to 0.9), 0.85 (95% CI 0.81 to 0.9), 0.93 (95% CI 0.9 to 0.96) and 0.88 (95% CI 0.8 to 0.95) at five-gestational-week stages, respectively. Compared to the predictive models with hemodynamic factors, the predictive model with pulse wave parameters had better prediction effects on HDP.Pulse waves had good predictive effects for HDP and provided appropriate guidance and a basis for non-invasive detection of HDP.

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.

Cost-effectiveness of induction of labor at 39 weeks vs expectant management by cervical examination

BACKGROUND

Previous analyses have demonstrated the cost effectiveness of elective induction of labor at 39 weeks of gestation for healthy nulliparous people. However, elective induction of labor is resource intensive, and optimal resource allocation requires a thorough understanding of which subgroups of patients will benefit most.

OBJECTIVE

This study aimed to determine whether induction of labor at 39 weeks of gestation is more cost-effective in patients with favorable or unfavorable cervical examinations.

STUDY DESIGN

We constructed 2 decision analysis models using TreeAge software: one modeling induction of labor at 39 weeks of gestation vs expectant management for a group of nulliparous patients with unfavorable cervical examinations and the other modeling induction of labor at 39 weeks of gestation vs expectant management for a group with favorable cervical examinations. Estimates of cost, probability, and health state utility were derived from the literature. Based on previous literature, we assumed that people with favorable cervical examinations would have a lower baseline rate of cesarean delivery and higher rates of spontaneous labor.

RESULTS

In our base case analysis, induction of labor at 39 weeks of gestation was cost-effective for patients with unfavorable cervical examinations, but not for patients with favorable cervical examinations. The incremental cost per quality-adjusted life year was 50-fold lower for people with unfavorable cervical examinations ($2150 vs $115,100). Induction of labor resulted in 3885 fewer cesarean deliveries and 58 fewer stillbirths per 100,000 patients for those with unfavorable examinations, whereas induction of labor resulted in 2293 fewer cesarean deliveries and 48 fewer stillbirths with labor induction for those with favorable cervical examinations. The results were sensitive to multiple inputs, including the likelihood of cesarean delivery, the cost of induction, the cost of vaginal or cesarean delivery, and the probability of spontaneous labor. In Monte Carlo analysis, the base case findings held true for 64.1% of modeled scenarios for patients with unfavorable cervixes and 55.4% of modeled scenarios for patients with favorable cervixes.

CONCLUSION

With a willingness-to-pay threshold of $100,000 per quality-adjusted life year, induction of labor at 39 weeks of gestation may be cost-effective for patients with unfavorable cervical examinations, but not for patients with favorable cervical examinations. This result was driven by the likelihood of labor in patients with favorable cervical examinations, and the resultant avoidance of prolonged pregnancy and its complications, including hypertensive disorders of pregnancy and stillbirths. Health systems may wish to prioritize patients with unfavorable cervical examinations for elective induction of labor at 39 weeks of gestation, which may be opposite to common practice.

Impact of the COVID-19 Pandemic on Obstetric Interventions at a Public Hospital

INTRODUCTION

In response to the COVID-19 pandemic, health systems quickly implemented changes in care delivery with a goal of balancing patient-focused obstetric care with the need to protect pregnant persons and health care providers from infection. Yet, there is no consensus within the scientific community on the impact these measures have on obstetric outcomes in vulnerable populations. We aimed to assess the impact of the COVID-19 pandemic on rates of obstetric procedures and severe maternal morbidity (SMM) among births at an urban safety net institution.

METHODS

We used an interrupted time series design to calculate risk ratios (RRs) and 95% confidence intervals (CIs) comparing monthly rates of labor induction, cesarean births (overall and among nulliparous, term, singleton, vertex births), operative vaginal births, and SMM among births occurring at a public hospital before (March 1, 2016, to February 29, 2020) and during (March 1, 2020, to May 31, 2021) the COVID-19 pandemic.

RESULTS

There were 10,714 and 2,736 births in the prepandemic and postpandemic periods, respectively. Overall, the rates of obstetric interventions and SMM were constant over the two time periods. There were no significant differences in rates of labor induction (42% during prepandemic period vs. 45% during pandemic period; RR, 1.12; 95% CI, 0.93-1.34), operative vaginal births (5% vs. 6%; RR, 1.24; 95% CI, 0.88-1.76), cesarean births (28% vs. 33%; RR, 1.10; 95% CI, 0.94-1.28), or nulliparous, term, singleton, vertex cesarean births (24% vs. 31%; RR, 1.27; 95% CI, 0.92-1.74). Rates of SMM (7% vs. 8%; RR, 1.19; 95% CI, 0.86-1.65) were also unchanged.

CONCLUSIONS

Our findings indicate that the rapid implementation of measures to reduce viral transmission in the labor and delivery setting did not materially affect routine clinical management or rates of serious maternal complications.

Neighborhood deprivation and severe maternal morbidity in a medicaid-Insured population in Georgia

BACKGROUND

Despite growing acceptance of the role of context in shaping perinatal risk, data on how neighborhood factors may identify high-risk obstetric patients is limited. In this study, we evaluated the effect of neighborhood deprivation and neighborhood racial composition on severe maternal morbidity (SMM) among persons delivered in a large public health system in Atlanta, Georgia.

METHODS

We conducted a population cohort study using electronic medical record data on all deliveries at Grady Memorial Hospital during 2011-2020. Using residential zip codes, we calculated neighborhood deprivation index based on data from the US Census. We used log-binomial regression with generalized estimating equations to estimate crude and adjusted relative risks (aRR) and 95% confidence intervals (CI) for the association between tertile of neighborhood deprivation and SMM, adjusting for demographic, clinical, and neighborhood-level (racial composition, food desert, and transit access) covariates.

RESULTS

Among 25,257 deliveries, 6.2% (1566) experienced SMM. Approximately 24.0%, 32.0%, and 44.0% of women lived in the lowest, middle, and highest tertile of neighborhood deprivation, respectively and 64.9% lived in a neighborhood with majority non-Hispanic Black residents. After adjustment, there was no association between neighborhood deprivation and SMM (aRR: 1.0 (0.8, 1.1)) or residence in a majority Black neighborhood and SMM (aRR:1.0 (0.9, 1.2)).

CONCLUSION

In this safety-net hospital, residence in a high deprivation or majority Black neighborhood did not predict SMM at or following delivery. Individual-level social determinants may better explain variation in risk, particularly in high-burden populations.

Dynamic risk prediction models for different subtypes of hypertensive disorders in pregnancy

Background

Hypertensive disorders in pregnancy (HDP) are diseases that coexist with pregnancy and hypertension. The pathogenesis of this disease is complex, and different physiological and pathological states can develop different subtypes of HDP.

Objective

To investigate the predictive effects of different variable selection and modeling methods on four HDP subtypes: gestational hypertension, early-onset preeclampsia, late-onset preeclampsia, and chronic hypertension complicated with preeclampsia.

Methods

This research was a retrospective study of pregnant women who attended antenatal care and labored at Beijing Maternity Hospital, Beijing Haidian District Maternal and Child Health Hospital, and Peking University People's Hospital. We extracted maternal demographic data and clinical characteristics for risk factor analysis and included gestational week as a parameter in this study. Finally, we developed a dynamic prediction model for HDP subtypes by nonlinear regression, support vector machine, stepwise regression, and Lasso regression methods.

Results

The AUCs of the Lasso regression dynamic prediction model for each subtype were 0.910, 0.962, 0.859, and 0.955, respectively. The AUC of the Lasso regression dynamic prediction model was higher than those of the other three prediction models. The accuracy of the Lasso regression dynamic prediction model was above 85%, and the highest was close to 92%. For the four subgroups, the Lasso regression dynamic prediction model had the best comprehensive performance in clinical application. The placental growth factor was tested significant (P &lt; 0.05) only in the stepwise regression dynamic prediction model for early-onset preeclampsia.

Conclusion

The Lasso regression dynamic prediction model could accurately predict the risk of four HDP subtypes, which provided the appropriate guidance and basis for targeted prevention of adverse outcomes and improved clinical care.

Risk of recurrent severe maternal morbidity in an urban safety net health system

BACKGROUND

Rates of severe maternal morbidity (SMM) are steadily increasing in the US and are highest among women who are Black, publicly insured, or deliver at a safety net hospital. There is limited information on the risk of SMM recurrence in subsequent births, particularly among socially vulnerable women.

OBJECTIVE

To estimate the risk of SMM recurrence among a singleton births in a large, public hospital system.

STUDY DESIGN

We conducted a population-based cohort study using electronic medical record data on deliveries occurring at an urban public hospital between 2011 and 2020. We included all women with two singleton deliveries at ≥20 weeks gestation (live or stillborn) during the study period and assessed SMM recorded at delivery or within 42 days postpartum. We used generalized linear models to estimate adjusted risk ratios (aRR), adjusted risk differences (aRD) and 95% confidence intervals (CI) for SMM at the subsequent birth, controlling for age, parity, self-reported race/ethnicity, insurance type, chronic hypertension and diabetes, and obesity at the index delivery.

RESULTS

Between 2011 and 2020, there were 26,994 singleton deliveries to 21,638 women. Among 4,368 women with two singleton births at ≥20 weeks gestation, 4.8% (n=211) had SMM at the index birth, and 5.7% (n=250) had SMM at the subsequent birth. SMM at the index birth was associated with an over 3-fold increased risk of SMM in a subsequent pregnancy (aRR 3.65, 95% CI: 2.65-5.03) and an excess risk of 12.9 per 100 deliveries (aRD 12.9, 95% CI: 7.7-18.1).

CONCLUSIONS

The results of our study suggest that women who experienced SMM in a prior birth are at increased risk for SMM recurrence and may warrant additional monitoring in subsequent pregnancies.

The Effect of Antiretroviral Therapy for the Treatment of HIV-1 in Pregnancy on Gestational Weight Gain

BACKGROUND

Gestational weight gain above the Institute of Medicine recommendations is associated with increased risk of pregnancy complications. The goal was to analyze the association between newer HIV antiretroviral regimens (ART) on gestational weight gain.

METHODS

This is a retrospective cohort study of pregnant women with HIV-1 on ART. The primary outcome was incidence of excess gestational weight gain. Treatment effects were estimated by ART regimen type using log-linear models for relative risk, adjusting for pre-pregnancy BMI and presence of detectable viral load at baseline.

RESULTS

303 pregnant women were included in the analysis. Baseline characteristics including pre-pregnancy BMI, viral load at prenatal care entry, and gestational age at delivery were similar by ART, including 53% of the entire cohort initiated ART before pregnancy ( p = NS). Excess gestational weight gain occurred in 29% of the cohort. Compared to non-INSTI or TAF exposed persons, receipt of INSTI+TAF had a 1.7-fold increased relative risk of excess gestational weight gain, (95%CI 1.18, 2.68, p< 0.01), while women who received TDF had a 0.64-fold decreased relative risk (95% CI 0.41, 0.99, p=0.047) of excess gestational weight gain. INSTI alone was not significantly associated with excess weight gain in this population. The effect of TAF without INSTI could not be inferred from our data. There was no difference in neonatal, obstetric, or maternal outcomes between the groups.

CONCLUSIONS

Pregnant women receiving ART with a combined regimen of INSTI and TAF have increased risk of excess gestational weight gain.

Gestational hypertensive disease and birthweight discordance in twin pregnancies: a systematic review and meta-analysis

INTRODUCTION

The objective of this systematic review was to explore the association between gestational hypertensive disease (GHD) and birthweight discordance in twin pregnancies.

METHODS

PubMed, Embase, Web of Science and Cochrane Library were systematically searched for studies reporting the risk of birthweight discordance in twin pregnancies complicated compared with those not complicated by GHD from establishment until July 2021. Risk of bias was assessed with the Newcastle-Ottawa Scale. According to the classification of GHD, sub-group analyses reporting cases with gestational hypertension (GH), chronic hypertension (CH) and preeclampsia (PE) were performed separately. Stratification by twin chorionicity (dichorionic (DC) and monochorionic (MC)) was also conducted. When there was substantial heterogeneity (I² ≥ 50%), the random effect mode was used to estimate the pooled risk ratio, otherwise the fixed effect model was used.

RESULTS

Nine studies (303,204 twin pregnancies) were included. GHD (OR 1.45, 95% CI 1.41-1.49) was a risk factor for intertwin birthweight discordance [PE (OR 1.69, 95% CI 1.33-2.16); CH (OR 1.59, 95% CI 1.46-1.73); GH (OR1.45, 95%Cl 1.10-1.92]. After stratification, birthweight discordance was related to GHD (OR 2.51, 95% CI 2.01-3.14), GH (OR 2.08, 95% CI 1.33-3.25) and PE (OR 2.74, 95% CI 2.09-3.61) in DC pregnancies, but no longer associated with GHD and PE in MC group.

CONCLUSIONS

Twin gestations complicated with GHD, especially in DC pregnancies, were at significantly higher risk of birthweight discordance.

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.

Predicting hypertensive disorders in pregnancy using multiple methods: Models with the placental growth factor parameter

BACKGROUND

Placental growth factor (PlGF), one of the biomarkers, has a certain predictive effect on hypertensive disorders in pregnancy (HDP).

OBJECTIVE

To study the HDP prediction effect of different methods for variable selection and modeling for models containing PlGF.

METHODS

For the model containing PlGF, the appropriate range of PlGF parameters needed to be selected. Step-logistic regression and lasso were used to compare the model effect of twice range selection. The PlGF model with good predictive effect and appropriate detecting gestational age was selected for the final prediction.

RESULTS

The effect of the model containing PlGF tested at 15-16 weeks was better than the PlGF value without comprehensive screening. The sensitivity of both methods was over 92%. By comprehensive comparison, the final model of lasso method in this study was more effective.

CONCLUSIONS

In this study, a variety of methods were used to screen models containing PlGF parameters. According to clinical needs and model effects, the optimal HDP prediction model with PlGF parameters in the second trimester of 15-26 weeks of pregnancy was finally selected.