Sickle cell anaemia with and without crises: An observational study of pregnancy outcomes

We assessed the pregnancy outcomes of patients with sickle cell crises. We carried out a retrospective study of 2 698 556 pregnancies in Quebec, Canada between 1989 and 2022. The primary exposure was sickle cell anaemia with crisis during or outside of pregnancy. Outcomes included severe maternal morbidity and other pregnancy complications. We used log-binomial regression models to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for the association between sickle cell crises and pregnancy outcomes. We found that patients with sickle cell crises were particularly at risk of severe maternal morbidity (RR 8.50, 95% CI 6.93-10.41), especially peripartum sepsis (RR 12.64, 95% CI 7.20-22.18) and acute renal failure (RR 32.37, 95% CI 16.99-61.67) compared with no sickling disorder. Patients with crises during pregnancy that required delivery (RR 15.58, 95% CI 11.92-25.33) or that resolved without requiring delivery (RR 7.39, 95% CI 4.64-11.78) were at risk of severe maternal morbidity. Sickle cell crises were associated with a range of other pregnancy complications, such as preterm birth and caesarean delivery. The findings suggest that sickle cell crises, including crises during or outside pregnancy, are associated with severe maternal morbidity and other pregnancy complications.