Postpartum Hospital Readmissions With and Without Severe Maternal Morbidity Within 1 Year of Birth, Oregon, 2012-2017

Postpartum readmission risk: a comparison between stillbirths and live births

BACKGROUND

Stillbirth occurs more commonly among pregnant people with comorbid conditions and obstetrical complications. Stillbirth also independently increases maternal morbidity and imparts a psychosocial hazard when compared with live birth. These distinct needs and burden may increase the risk for postpartum readmission after stillbirth.

OBJECTIVE

This study aimed to examine the risk for maternal postpartum readmission after stillbirth in comparison with live birth and to identify indications for readmission and the associated risk factors.

STUDY DESIGN

This was a retrospective cohort of patients with singleton stillbirths or live births, delivered at ≥20 weeks' gestation, who were identified from the 2019 Nationwide Readmissions Database. The primary outcome was all-cause readmission within 6 weeks of discharge from the childbirth hospitalization. The association between stillbirth (vs live birth) and risk for readmission was assessed using multivariable regression models with adjustment for maternal age, sociodemographic characteristics, maternal and obstetrical conditions, and delivery characteristics. Within the stillbirth group, risk factors for readmission were further examined using multivariable regression. The secondary outcomes included principal indication for readmission (categorized based on principal diagnosis code of the readmission hospitalization) and timing of readmission (number of weeks after childbirth hospitalization). Differences in these secondary outcomes were compared between the stillbirth and live birth groups using chi-square tests. All analyses accounted for the complex sample design to generate nationally representative estimates.

RESULTS

Postpartum readmission occurred in 2.7% of 16,636 patients with stillbirths, whereas it occurred in 1.6% of 2,870,677 patients with live births (unadjusted risk ratio, 1.65; 95% confidence interval, 1.47-1.86). The higher risk for readmission after stillbirth (vs live birth) persisted after adjusting for maternal, obstetrical, and delivery characteristics (adjusted risk ratio, 1.27; 95% confidence interval, 1.11-1.46). The distribution of principal indication for readmission differed after stillbirth and after live birth and included hypertension (30.2% vs 39.5%; unadjusted risk ratio, 0.76; 95% confidence interval, 0.63-0.93), mental health or substance use disorders (6.8% vs 3.6%; unadjusted risk ratio, 1.90; 95% confidence interval, 1.15-3.16), and venous thromboembolism (5.8% vs 2.0%; unadjusted risk ratio, 2.87; 95% confidence interval, 1.60-5.17). Among patients with stillbirths, 56.0% of readmissions occurred within 1 week, 71.8% within 2 weeks, and 88.1% within 4 weeks; the timing of readmission did not differ significantly between the stillbirth and live birth cohorts. Pregestational diabetes (adjusted risk ratio, 1.87; 95% confidence interval, 1.20-2.93), gestational diabetes (adjusted risk ratio, 1.67; 95% confidence interval, 1.03-2.71), hypertensive disorders of pregnancy (adjusted risk ratio, 1.80; 95% confidence interval, 1.31-2.47), obesity (adjusted risk ratio, 1.46; 95% confidence interval, 1.01-2.12), and primary cesarean delivery (adjusted risk ratio, 1.74; 95% confidence interval, 1.17-2.58) were associated with a higher risk for readmission after stillbirth, whereas higher household income was associated with a lower risk for readmission (eg, adjusted risk ratio for income ≥$82,000 vs $1-$47,999, 0.48; 95% confidence interval, 0.30-0.77).

CONCLUSION

When compared with live births, the risk for postpartum readmission was higher after stillbirths, even after adjustment for differences in the patient demographic and clinical characteristics. Readmission for mental health or substance use disorders and venous thromboembolism is more common after stillbirths than after live births.

Severe maternal morbidity from pregnancy through 1 year postpartum

BACKGROUND

Few recent studies have examined the rate of severe maternal morbidity occurring during the antenatal and/or postpartum period to 42 days after delivery. However, little is known about the rate of severe maternal morbidity occurring beyond 42 days after delivery.

OBJECTIVE

This study aimed to examine the distribution of severe maternal morbidity and its indicators during antenatal, delivery, and postpartum hospitalizations to 365 days after delivery and to estimate the increase in severe maternal morbidity rate and its indicators after accounting for antenatal and postpartum severe maternal morbidity to 365 days after delivery.

STUDY DESIGN

This was a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from Michigan, Oregon, and South Carolina from 2008 to 2020. This study examined the distribution of severe maternal morbidity, nontransfusion severe maternal morbidity, and severe maternal morbidity indicators during antenatal, delivery, and postpartum hospitalizations to 365 days after delivery. Subsequently, this study examined "severe maternal morbidity cases added," which represent cases among unique individuals that are included by considering the antenatal and postpartum periods but that would be missed if only the delivery hospitalization cases were included.

RESULTS

A total of 64,661 (2.5%) individuals experienced severe maternal morbidity, whereas 37,112 (1.4%) individuals experienced nontransfusion severe maternal morbidity during antenatal, delivery, and/or postpartum hospitalization. A total of 31% of severe maternal morbidity cases were added after accounting for severe maternal morbidity occurring during the antenatal or postpartum hospitalization to 365 days after delivery, whereas 49% of nontransfusion severe maternal morbidity cases were added after accounting for nontransfusion severe maternal morbidity occurring during the antenatal or postpartum periods. Severe maternal morbidity occurring between 43 and 365 days after delivery contributed to 12% of all severe maternal morbidity cases, whereas nontransfusion severe maternal morbidity occurring between 43 and 365 days after delivery contributed to 19% of all nontransfusion severe maternal morbidity cases.

CONCLUSION

Our study showed that a total of 31% of severe maternal morbidity and 49% of nontransfusion severe maternal morbidity cases were added after accounting for severe maternal morbidity occurring during the antenatal or postpartum hospitalization to 365 days after delivery. Our findings highlight the importance of expanding the severe maternal morbidity definition beyond the delivery hospitalization to better capture the full period of increased risk, identify contributing factors, and design strategies to mitigate this risk. Only then can we improve outcomes for mothers and subsequently the quality of life of their infants.

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.

Trends in racial/ethnic disparities in postpartum hospital readmissions in California from 1997 to 2018

BACKGROUND

Postpartum readmission is an important indicator of postpartum morbidity. The likelihood of postpartum readmission is highest for Black individuals. However, it is unclear whether the likelihood of postpartum readmission has changed over time according to race/ethnicity. Little is also known about the factors that contribute to these trends.

OBJECTIVE

This study aimed to: (1) examine trends in postpartum readmission by race/ethnicity, (2) examine if prenatal or clinical factors explain the trends, and (3) investigate if racial/ethnic disparities changed over time.

STUDY DESIGN

We examined trends in postpartum readmission, defined as hospitalization within 42 days after birth hospitalization discharge, using live birth and fetal death certificates linked to delivery discharge records from 10,711,289 births in California from 1997 to 2018. We used multivariable logistic regression models that included year and year-squared (to allow for nonlinear trends), overall and stratified by race/ethnicity, to estimate the annual change in postpartum readmission during the study period, represented by odds ratios and 95% confidence intervals. We then adjusted models for prenatal (eg, patient demographics) and clinical (eg, gestational age, mode of birth) factors. To determine whether racial/ethnic disparities changed over time, we calculated risk ratios for 1997 and 2018 by comparing the predicted probabilities from the race-specific, unadjusted logistic regression models.

RESULTS

The overall incidence of postpartum readmission was 10 per 1000 births (17.4/1000 births for non-Hispanic Black, 10/1000 for non-Hispanic White, 7.9/1000 for non-Hispanic Asian/Pacific Islander, and 9.6/1000 for Hispanic individuals). Odds of readmission increased for all groups during the study period; the increase was greatest for Black individuals (42% vs 21%-29% for the other groups). After adjustment for prenatal and clinical factors, the increase in odds was similar for Black and White individuals (12%). The disparity in postpartum readmission rates relative to White individuals increased for Black individuals (risk ratio, 1.68 in 1997 and 1.90 in 2018) and more modestly for Hispanic individuals (risk ratio, 1.02 in 1997 and 1.05 in 2018) during the study period. Asian/Pacific Islander individuals continued to have lower risk than White individuals during the study period (risk ratio, 0.87 in 1997 and 0.82 in 2018).

CONCLUSION

The rate of postpartum readmissions increased from 1997 to 2018 in California across all racial/ethnic groups, with the greatest increase observed for Black individuals. Racial/ethnic differences in the trend were more modest after adjustment for prenatal and clinical factors. It is important to find ways to prevent further increases in postpartum readmission, especially among groups at highest risk.

Hospital Encounters Within 1 Year Postpartum Across Insurance Types, Oregon 2012-2017

BACKGROUND

Little is known about the timing and frequency of postpartum hospital encounters and postpartum visit attendance and how they may be associated with insurance types. Research on health insurance and its association with postpartum care utilization is often limited to the first 6 weeks.

OBJECTIVE

To assess whether postpartum utilization (hospital encounters within 1 year postpartum and postpartum visit attendance within 12 weeks) differs by insurance type at birth (Medicaid, high deductible health plans, and other commercial plans) and whether rates of hospital encounters differ by postpartum visit attendance and insurance status.

METHODS

Time-to-event analysis of Oregon hospital births from 2012 to 2017 using All Payer All Claims data. We conducted weighted Cox Proportional Hazard regressions and accounted for differences in insurance type at birth using multinomial propensity scores.

RESULTS

Among 202,167 hospital births, 24.9% of births had at least 1 hospital encounter within 1 year postpartum. Births funded by Medicaid had a higher risk of a postpartum emergency department (ED) visit (hazard ratio: 2.05, 95% CI: 1.99, 2.12) and lower postpartum visit attendance (hazard ratio: 0.71, 95% CI: 0.70, 0.72) compared with commercial plans. Among Medicaid beneficiaries, missing the postpartum visit in the first 6 weeks was associated with a lower risk of subsequent readmissions (adjusted hazard ratio 0.77, 95% CI: 0.68, 0.87) and ED visits (adjusted hazard ratio: 0.87 (0.85, 0.88).

CONCLUSIONS

Medicaid beneficiaries received more care in the ED within 1 year postpartum compared with those enrolled in other commercial plans. This highlights potential issues in postpartum care access.

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.