Among pregnant women with sickle cell disease (SCD), the risk for severe maternal morbidity (SMM) at delivery is higher than that among women without SCD, according to findings from a cross-sectional study published in JAMA Network Open.

The current study was a secondary analysis of data from the National Inpatient Sample—a nationally representative sample of 20% of acute hospitalizations in the United States between 2012 and 2018. The data set included all hospital admissions with a code for delivery of a pregnancy among individuals aged 11 to 55 years. The data involved were analyzed between September 2021 and August 2022.

Recognizing that pregnancy outcomes are historically poor among women with SCD in the United States, most of whom are Black, the investigators sought to evaluate the rates and risk of SMM in birthing women with SCD and what proportion of the increased risk for adverse pregnancy outcomes in SCD is associated with racial disparities encountered by Black patients.

Main outcomes and measures included SMM, as measured by the SMM index from the US Centers for Disease Control and Prevention (CDC), which includes 21 highly morbid obstetric complications. Although transfusion and sickle cell vaso-occlusive crisis are 2 of the 21 possible complications in the CDC’s SMM index, these 2 complications were excluded from the analysis because of confounding by SCD. The final analytical models thus included 19 of 21 SMM outcomes, which were considered both individually and as a composite SMM variable.

The study sample comprised 5,401,899 deliveries, with 3901 of the deliveries among women with SCD and 742,164 of the deliveries among Black women. Compared with the non-Black controls,  the patients with SCD and the Black patients were younger (mean age: SCD, 27.2±5.9 years; Black, 27.1±6.1 years vs non-Black controls, 28.7±5.9 years; P <.001) and more likely to have public insurance (SCD, 2609 deliveries [67.3%]; Black, 496,828 deliveries [65.4%] vs non-Black controls, 1,880,198 deliveries [40.8%]; P <.001).

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The mortality rate in deliveries among women with SCD was 26 times higher than in the non-Black control group and more than 10 times greater than among pregnant Black women without SCD (deaths 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 controls, 0.5; 95% CI, 0.5-0.6).

Compared with the non-Black control group, deliveries among women with SCD had a significantly higher likelihood of SMM (adjusted odds ratio [aOR], 7.22; 95% CI, 6.25-8.34; P <.001), particularly 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 were responsible for a median 28.9% (range, 21.2% to 33.1%) of the increased risk in deliveries among women with SCD, as well as 40% to 50% of the increased risk for acute kidney failure, intrauterine fetal demise, and eclampsia.

The authors concluded, “Our findings compel scientific, clinical, and political efforts to improve outcomes for pregnant people with SCD.”


Early ML, Eke AC, Gemmill A, Lanzkron S, Pecker LH. Severe maternal morbidity and mortality in sickle cell disease in the National Inpatient Sample, 2012-2018. JAMA Netw Open. 2023;6(2):e2254552. doi:10.1001/jamanetworkopen.2022.54552