Risk factors for immediate postpartum sickle cell disease-specific maternal morbidity

Pregnant individuals with sickle cell disease (SCD) are more likely to have postpartum complications. In this retrospective single-centre study, 201 pregnancies from 145 individuals were assessed between 2000 and 2018 for the presence of a composite of immediate postpartum complications from admission during delivery to discharge, which included vaso-occlusive pain events, acute chest syndrome, infection (blood, urine, pulmonary) and/or new-onset hypoxia. Hypoxia was defined as SpO₂ below 92%. An immediate postpartum complication occurred in 74 pregnancies (37%), of which 97% experienced a vaso-occlusive pain event. No immediate postpartum deaths were recorded. Pregnancies with HbSS/HbSβ0 as compared to HbSC/HbSβ+ had a higher incidence of the composite outcome (51% vs. 19%). On univariate analysis, HbSS/HbSβ0 genotype was associated with a higher likelihood of developing a postpartum complication (OR 4.49, 95%CI 2.35-8.57; p < 0.0001); however, this significance was reduced on multivariable analysis. The strongest risk factors associated with experiencing the composite outcome on multivariable analysis were hypoxia during pregnancy (OR 4.95, 95%CI 1.86-13.23; p = 0.001) and an unscheduled caesarean delivery (OR 2.67; 95%CI 1.26-5.64; p = 0.01). Future studies need to address whether correcting hypoxia and use of predictive scores to guide the need for a scheduled caesarean delivery can reduce immediate postpartum complication rates.