New Data Show Severe Maternal Morbidity is a Threat to People with Sickle Cell Disease

Macy Early, BA

Poor pregnancy outcomes among individuals with sickle cell disease (SCD), particularly those of Black race, have been well-documented in the US. A new study aimed to compare delivery outcomes of Black individuals with and without sickle cell disease, alongside a non-Black population as a control group to identify any progress.¹

According to the results published today, severe maternal morbidity was significantly higher in patients with sickle cell disease than without, and racial disparities were linked to adverse outcomes. Macy L. Early, BA, Division of Hematology, Department of Medicine, Johns Hopkins University School of Medicine, and investigators assessed nationally representative data on acute hospital admissions between 2012-2018.

Complications that have been observed at increased rates in this population include eclampsia, sepsis, venous thromboembolism, and intrauterine growth restriction. As referenced in the study, the maternal mortality rate in patients with sickle cell disease from 1999-2008 was between 7.2 and 16 deaths for every 10,000 sickle cell disease pregnancies, compared with the general population's rate of 1.3 deaths per 10,000 pregnancies.

"Our findings compel scientific, clinical, and political effort to improve outcomes for pregnant people with SCD," investigators wrote.

The National Analysis

In addition to comparing delivery outcomes between the study groups, the team measured the association of racial disparities with adverse outcomes in sickle cell disease pregnancies. Multiple logistic regression was employed to establish the odds for adverse pregnancy outcomes, and the US Centers for Disease Control and Prevention (CDC) index was referenced to assess severe maternal mortality.

Data for this investigation were obtained from National Inpatient Sample. The sample consisted of 20% of acute hospital admissions in the US from 2012 to 2018 that contained codes for delivery of a pregnancy among patients aged 11-55 years.

A total of 5,401,899 deliveries made up the sample; 3901 were patients with sickle cell disease, and 742,164 were patients with Black race. Investigators analyzed data from the cross-sectional study from September 2021 through August 2022.

Updated Maternal Morality and Morbidity Rates in Sickle Cell Disease

When compared with the non-Black control group, the patients with sickle cell disease and those with Black race were more likely to have public insurance, and were younger. The mean age of those in the SCD group (27.2) was close to that of the group of Black patients (27.1), both of which differed from the control group (28.7) by more than one year.

Results demonstrated a 13.3 rate of maternal mortality per 10,000 deliveries in the 2609 sickle cell disease deliveries, which was 26 times greater than the rate of 0.5 for the control group (1,880,198 deliveries), and 10 times greater than the rate of 1.2 for Black patients without sickle cell disease (496,828 deliveries).

Patients with sickle cell disease showed overall higher odds (7.22) for severe maternal morbidity compared with the control group, with steep differences related to cerebrovascular events (22.0), and thromboembolism (17.34).

After analyses, investigators calculated that racial disparities could be attributed to a median 28.9% of the increased risk in deliveries among patients with sickle cell disease. Racial disparities also explained 40%-50% of increased risk for acute kidney failure (56.9%), intrauterine fetal demise (47.8%), and eclampsia (42.1%).

"In this representative cross-sectional sample of pregnancies in the US, pregnancy in people with SCD were at very high risk, with mortality rates among SCD deliveries 26 times the general population," investigators wrote. "Despite advances in SCD management and high-risk pregnancy care, at the national level, outcomes in this population have not improved since the last NIS analysis of data from 1999 to 2008."

References

1. 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