Retrospective Analysis of Transfusions on Sickle Cell–Related Morbidity in Pregnancy

Abstract   Presentation Date: 6/8/2024 Presentation Start Time: 6:00 PM Background Despite advancements in medical care, maternal and perinatal mortality rates among pregnant individuals with sickle cell disease (SCD) remain disproportionately high [1]. While existing evidence suggests a potential benefit of prophylactic transfusions with reference to maternal and perinatal outcomes, the limited number of studies and methodological constraints necessitate further investigation [2,3]. Considering these findings, we have attempted to retrospectively analyze the incidence of maternal and perinatal complications among transfused pregnant patients of different sickle genotypes. Methods We conducted a retrospective analysis of medical records from New York City Health and Hospitals/Kings County, which is an urban inner-city hospital providing care to an underserved population. We identified pregnant patients diagnosed with sickle cell disease for nine years between January 1, 2015, and January 1, 2024. Access to patient medical records was facilitated through the hospital’s EPIC and Quadramed software. We performed statistical analysis on maternal sickle cell/obstetric and perinatal complications among patients and stratified them by genotype, mean hemoglobin level, race, and age. Results Patients with homozygous sickle cell disease (HbSS) comprised 69% of the study population, with 66% of the patients being above 35 years of age. The mean hemoglobin for patients with HbSS disease was approximately 7.0 g/dl at baseline, which was maintained relatively constant throughout their pregnancy for the vast majority. In contrast, patients with heterozygous sickle genotypes like HbSC and HbS Beta+ thalassemia had mean baseline hemoglobin levels of approximately 9.5 g/dl and approximately 7.0 g/dl, respectively, with mean pregnancy levels averaging at approximately 8.0 g/dl for both groups. Obstetric complications were more prevalent among HbSS patients compared to other genotypes. In the HbSS subgroup, pre-eclampsia was most prevalent (100%), followed by postpartum hemorrhage (56%) and cesarean section (69%). Among HbSC patients, none experienced pre-eclampsia, 44% had postpartum hemorrhage, and 22% underwent cesarean section. Among HbS Beta+ thalassemia patients, none experienced pre-eclampsia or postpartum hemorrhage, and 9% underwent cesarean section.  Pre-eclampsia rates were significantly higher in the HbSS genotype (100%) and did not occur in other genotypes at their hemoglobin level. Miscarriages occurred in 80% of HbSS patients as compared to 20% of HbSC patients, while none were noted among HbS Beta+ thalassemia patients. Fetal complications also varied among genotypes. Intrauterine growth retardation (IUGR) was predominantly noted in HbSS patients (67%), while only 33% of HbSC patients encountered the same, and none were noted in HbS Beta+ thalassemia patients.  Fetal distress was noted in only 33% of HbSS patients, while it accounted for 67% among HbSC patients, and none were noted in HbS Beta+ thalassemia patients. Intrauterine fetal demise was noted in only 33% of HbSS patients, while it accounted for 67% among HbSC patients, and none were noted in HbS Beta+ thalassemia patients. Vaso-occlusive episodes occurred in 29% of all patients, with varying incidence among different genotypes. Among HbSS patients, 84% experienced Vaso-occlusive episodes, compared to 8% among HbSC patients and 8% among HbS Beta+ thalassemia patients. Transfusion rates during pregnancy were highest among HbSS patients (80%) compared to 16% among HbSC patients and 4% among HbS Beta+ thalassemia patients. Conclusion Our retrospective analysis underscores the complex association between pregnancy-related complications of sickle cell disease and transfusion therapy. While our findings generally highlight a correlation between mean hemoglobin levels and adverse outcomes, further research is imperative to elucidate the optimal management strategies for pregnant individuals with SCD. Prospective studies integrating comprehensive clinical and laboratory assessments are essential to delineate the role of prophylactic transfusions in mitigating maternal, fetal, and sickle cell-related complications. Such endeavors are pivotal in advancing evidence-based practices and ultimately improving outcomes for this vulnerable patient population.