PREGNANT patients with sickle cell disease (SCD) have an increased risk of severe maternal morbidity (SMM), according to a recent cohort study. While these findings are not surprising, explained author Veronica Gillispie-Bell, Ochsner Health Center – Kenner, Louisiana, USA, they are reminder of the importance of monitoring these patients closely to mitigate their risk and ensure they are kept out of a crisis.
The team analysed state health department data from 8,693,616 patients, 1.57% of whom had SMM, and 0.7% of whom had non-transfusion SMM. SMM included sepsis, SCD crisis, and heart failure, as well as 13 other life-threatening maternal conditions and five life-saving procedures. . Incidence of SCD is higher in Black patients, and 11% of the Black patients in this study experience more than one SMM.
In total, 0.37% of Black patients had SCD. Among those, the crude ratio of SMM during delivery hospitalisation was 11.9 (95% confidence interval [CI]: 11.3–12.5), while crude risk ratio of non-transfusion SMM was 19.8 (95% CI: 18.5–21.2). The adjusted risk ratios were 3.8 (95%: 3.3–4.5) and 6.5 (95% CI: 5.3-8.0), respectively. The attributable risk for SSM for SCD was 8.1 per 10,000 adjusted population, and maternal morbidity for SCD was 14 per 10,000 deliveries, versus one per 10,000 without SCD. The risk for readmission with SCD persisted for one year after delivery.
SCD led to a 3.8-fold increase in risk for SMM, which is similar to pre-existing anaemia as a risk factor for SMM; however, the risk for non-transfusion SMM was increased 6.5-fold, which is higher than the risk from severe pre-eclampsia. The study did not confirm whether the association between SCD and SSM was direct or indirect; however, researchers explained it is likely that SCD, associated to previously identified clinical risk factors, contributes to racial disparities in SMM.
The team acknowledged limitations of the study, including lack of data on SMM severity, when SMM occurred, analysis by genotype, and incidence in a particular state. However, the team stated the results confirm the urgent need for new interventions for SCD: “Preconception care and management by a multidisciplinary team of obstetricians, haematologists, anaesthesiologists, and other healthcare professionals are critical for improved pregnancy outcomes among patients with SCD.”
