Severe Maternal Morbidity and Mortality in Sickle Cell Disease in the National Inpatient Sample, 2012-2018

Abstract

ImportancePregnancy outcomes are historically poor among people with sickle cell disease (SCD) in the US, most of whom have Black race. Whether outcomes have improved is unknown.ObjectiveTo tabulate adverse pregnancy outcomes among patients with SCD, comparing outcomes of deliveries among Black people with SCD with those of Black people without SCD and a control non-Black population, and to measure the association of racial disparities with adverse outcomes in SCD pregnancies.Design, Setting, and ParticipantsThis cross-sectional study was a secondary analysis involving data from National Inpatient Sample, a nationally representative sample of 20% of acute hospital admissions in the US, between 2012 and 2018. The data set included all admissions with codes for delivery of a pregnancy among people aged 11 to 55 years. Data were analyzed from September 2021 to August 2022.ExposuresSCD, racial disparities.Main Outcomes and MeasuresSevere maternal morbidity (SMM) as measured by the US Centers for Disease Control and Prevention’s index alongside other outcomes; multiple logistic regression was used to compare the odds for adverse pregnancy outcomes.ResultsThe sample included 5 401 899 deliveries, including 3901 deliveries among people with SCD and 742 164 deliveries among people with Black race. Compared with the non-Black control group, patients with SCD and Black patients were younger (mean [SD] age: SCD, 27.2 [5.9] years; Black, 27.1 [6.1] years vs 28.7 [5.9] years) and more likely to have public insurance (SCD, 2609 deliveries [67.3%]; Black, 496 828 deliveries [65.4%] vs 1 880 198 deliveries [40.8%]). The maternal mortality rate in deliveries among people with SCD was 26 times greater than in the non-Black control group and more than 10 times greater than among Black pregnant people without SCD (Per 10 000 deliveries: SCD 13.3; 95% CI, 5.7-31.2; Black race, 1.2; 95% CI, 1.0-1.5; non-Black control 0.5; 95% CI, 0.5-0.6). Compared with the control group, SCD deliveries had higher odds of SMM (adjusted odds ratio [aOR], 7.22; 95% CI, 6.25-8.34; P < .001), especially cerebrovascular events (aOR, 22.00; 95% CI, 15.25-31.72; P < .001) and thromboembolism (aOR, 17.34; 95% CI, 11.55-26.03; P < .001). Racial disparities explained a median (IQR) 28.9% (21.2%-33.1%) of the increased risk in deliveries to people with SCD and between 40% and 50% of the increased risk for acute kidney failure (excess risk [ER], 56.9%; 95% CI, 54.3%-59.3%), intrauterine fetal demise (ER, 47.8%; 95% CI, 46.6%-49.1%), and eclampsia (ER, 42.1%; 95% CI, 37.9%-46.1%).Conclusions and RelevanceIn this large cross-sectional study of pregnancy outcomes in people with SCD, the risk for SMM was higher compared with deliveries among people without SCD, especially for thrombotic events, organ failure, and death. Racial disparities were associated with adverse outcomes. Our findings compel scientific, clinical, and political effort to improve outcomes for pregnant people with SCD.

Association of Sickle Cell Disease With Racial Disparities and Severe Maternal Morbidities in Black Individuals

“…Since we initiated our analyses, 2 studies were published examining the association between SCD and SMM . One was conducted using the National Inpatient Sample (2012-2018) and reported that during the delivery hospitalization, the SMM rate excluding transfusion and SCD crisis was 5.7% among individuals with SCD and 0.7% among control patients of other than Black race, resulting in an OR of 7.2 (95% CI, 6.3-8.3) after adjusting for hospital and patient sociodemographic characteristics . The other study was conducted at a single center in Atlanta, Georgia (2011-2020), and reported that during the delivery hospitalization, the SMM rate excluding crisis was 65.9% among individuals with SCD and 11.7% among individuals without SCD for an RR of 5.4 (95% CI, 4.6-6.3) after adjusting for age, parity, insurance, chronic hypertension, diabetes, obesity, and multiple gestation .…”

“…Another study reported increased odds for sepsis (OR, 6.8; 95% CI, 4.4-10.5) . Studies conducted in the US examining maternal mortality reported rates to be 0.07%, 0.10%, 0.13%, and 0.16% . Our rate of 0.14% falls within the range of these studies.…”

“…Since we initiated our analyses, 2 studies were published examining the association between SCD and SMM . One was conducted using the National Inpatient Sample (2012-2018) and reported that during the delivery hospitalization, the SMM rate excluding transfusion and SCD crisis was 5.7% among individuals with SCD and 0.7% among control patients of other than Black race, resulting in an OR of 7.2 (95% CI, 6.3-8.3) after adjusting for hospital and patient sociodemographic characteristics .…”

“…Previous studies examining pregnancy outcomes among individuals with SCD have reported increased risks for maternal mortality, preeclampsia, stillbirth, preterm delivery, and small for gestational age . However, very few studies have examined SMM risk among individuals with SCD . Thus, we examined (1) the contribution of SCD to racial disparities in SMM and (2) the risk of mortality, SMM, and SMM indicators among Black individuals with SCD vs those without.…”

Comment on: Infertility and treatment‐seeking practices among females and males with sickle cell disease in the Sickle Cell Disease Implementation Consortium registry

“…Also, in the most recent National Inpatient Sample, the average age of pregnancy in women with SCD pregnancy was 27 years and did not differ from unaffected Black women. 12 While the average age of first paternity in SCD is not established, paternity appears to be low in a recent publication. 13 Finally, Stevenson et al cite a single, population-based infertility study to provide relative context of the problem, 9 whereas more contemporary data show that infertility rates among married/cohabiting women in the general population may be only 5%-8%.…”