Serial prophylactic exchange blood transfusion in pregnant women with sickle cell disease (TAPS-2): study protocol for a randomised controlled feasibility trial

Managing sickle cell disease and related complications in pregnancy: results of an international Delphi panel

ABSTRACT

Data to guide evidence-based management of pregnant people with sickle cell disease (SCD) are limited. This international Delphi panel aimed to identify consensus among multidisciplinary experts for SCD management during pregnancy. The 2-round Delphi process used questionnaires exploring 7 topics (antenatal care, hydroxyurea use, transfusion, prevention of complications, treatment of complications, delivery and follow-up, and bottlenecks and knowledge gaps) developed by a steering committee. Thirteen panelists (hematologists, physiologists, obstetricians, maternal fetal medicine, and transfusion medicine physicians) from the United States, the United Kingdom, Turkey, and France completed the first survey; 12 panelists completed the second round. Anonymized responses were collected and summarized by a contract research organization (Akkodis Belgium). Consensus and strong consensus were predefined as 75% to 90% (9-10 of 12) and >90% (≥11 of 12) of panelists, respectively, agreeing or disagreeing on a response to a predefined clinical scenario or statement. In several areas of SCD management, consensus was achieved: experts recommended performing at least monthly multidisciplinary antenatal follow-up, administering prophylactic aspirin for preeclampsia prevention between gestational weeks 12 and 36, initiating prophylactic transfusion therapy in certain cases, or choosing automated red blood cell exchange over other transfusion methods for patients with iron overload or severe acute chest syndrome. No consensus was reached on several topics including the prophylactic aspirin dose, indications for starting infection prophylaxis, routine use of prophylactic transfusions, or use of prophylactic transfusions for preventing fetal complications. These recommendations could inform clinical care for patients with SCD who are pregnant in the absence of large clinical trials involving this population; the identified knowledge gaps can orient future research.

Red Blood Cell Exchange as a Valid Therapeutic Approach for Pregnancy Management in Sickle Cell Disease: Three Explicative Cases and Systematic Review of Literature

Pregnancy in women with sickle cell disease (SCD) is a high-risk situation, especially during the third trimester of gestation and in the post-partum period, due to chronic hypoxia and vaso-occlusive phenomena occurring in the maternal-fetal microcirculation: as a result, unfavorable outcomes, such as intra-uterine growth restriction, prematurity or fetal loss are more frequent in SCD pregnancies. Therefore, there is a consensus on the need for a strict and multidisciplinary follow-up within specialized structures. Transfusion support remains the mainstay of treatment of SCD pregnancies, whereas more targeted modalities are still controversial: the benefit of prophylactic management, either by simple transfusions or by automated red blood cell exchange (aRBCX), is not unanimously recognized. We illustrate the cases of three SCD pregnant patients who underwent aRBCX procedures at our institution in different clinical scenarios. Moreover, we carried out a careful literature revision to investigate the management of pregnancy in SCD, with a particular focus on the viability of aRBCX. Our experience and the current literature support the use of aRBCX in pregnancy as a feasible and safe procedure, provided that specialized equipment and an experienced apheresis team is available. However, further research in this high-risk population, with appropriately powered prospective trials, is desirable to refine the indications and timing of aRBCX and to confirm the advantages of this approach on other transfusion modalities.

Serial prophylactic exchange blood transfusion in pregnant women with sickle cell disease (TAPS-2): statistical and qualitative analysis plan for a randomised controlled feasibility trial

BACKGROUND

There are significant knowledge gaps regarding the effectiveness of serial prophylactic exchange blood transfusion (SPEBT) for pregnant women with sickle cell disease (SCD). The protocol for the randomised feasibility trial assessing SPEBT versus usual care in women with SCD (TAPS2 trial) has previously been published. This publication outlines the statistical and qualitative analysis plan for the study.

METHODS AND DESIGN

TAPS2 is a randomised two-arm phase 2 feasibility trial with a nested qualitative study and health economic evaluation. Up to 50 pregnant women with SCD and a singleton pregnancy will be recruited and individually randomised to either SPEBT approximately every 6-10 weeks until delivery (intervention arm) or to usual care (control arm). Information will be collected on a range of feasibility and clinical outcomes.

RESULTS

Due to the impact of COVID-19 on study recruitment, the initial study period of 24 months was extended to 48 months. Other protocol updates designed to mitigate the impact of COVID-19-related disruption included allowing for remote consent and conducting all qualitative interviews by telephone. The primary outcome for the trial is the overall recruitment rate. The number of women screened, eligible, consented, randomised and withdrawn will be summarised as a CONSORT flow diagram. Differences in clinical outcomes will additionally be presented as an initial assessment of efficacy and to inform sample size calculations for a future definitive trial. Qualitative interviews with trial participants and clinicians will be analysed using reflexive thematic analysis; data from interviews with participants who declined to participate in the trial will be extracted and incorporated into summary tables to report key findings. The health economic analysis plan is not covered by this update.

CONCLUSION

The publication of this analysis plan is designed to aid transparency and to reduce the potential for reporting bias.

TRIAL REGISTRATION

NIH registry ( www.

CLINICALTRIALS

gov ), registration number NCT03975894 (registered 05/06/19); ISRCTN ( www.isrctn.com ), registration number ISRCTN52684446 (retrospectively registered 02/08/19).

Severe Maternal Morbidity and Mortality in Sickle Cell Disease in the National Inpatient Sample, 2012-2018

IMPORTANCE

Pregnancy outcomes are historically poor among people with sickle cell disease (SCD) in the US, most of whom have Black race. Whether outcomes have improved is unknown.

OBJECTIVE

To tabulate adverse pregnancy outcomes among patients with SCD, comparing outcomes of deliveries among Black people with SCD with those of Black people without SCD and a control non-Black population, and to measure the association of racial disparities with adverse outcomes in SCD pregnancies.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was a secondary analysis involving data from National Inpatient Sample, a nationally representative sample of 20% of acute hospital admissions in the US, between 2012 and 2018. The data set included all admissions with codes for delivery of a pregnancy among people aged 11 to 55 years. Data were analyzed from September 2021 to August 2022.

EXPOSURES

SCD, racial disparities.

MAIN OUTCOMES AND MEASURES

Severe maternal morbidity (SMM) as measured by the US Centers for Disease Control and Prevention's index alongside other outcomes; multiple logistic regression was used to compare the odds for adverse pregnancy outcomes.

RESULTS

The sample included 5 401 899 deliveries, including 3901 deliveries among people with SCD and 742 164 deliveries among people with Black race. Compared with the non-Black control group, patients with SCD and Black patients were younger (mean [SD] age: SCD, 27.2 [5.9] years; Black, 27.1 [6.1] years vs 28.7 [5.9] years) and more likely to have public insurance (SCD, 2609 deliveries [67.3%]; Black, 496 828 deliveries [65.4%] vs 1 880 198 deliveries [40.8%]). The maternal mortality rate in deliveries among people with SCD was 26 times greater than in the non-Black control group and more than 10 times greater than among Black pregnant people without SCD (Per 10 000 deliveries: SCD 13.3; 95% CI, 5.7-31.2; Black race, 1.2; 95% CI, 1.0-1.5; non-Black control 0.5; 95% CI, 0.5-0.6). Compared with the control group, SCD deliveries had higher odds of SMM (adjusted odds ratio [aOR], 7.22; 95% CI, 6.25-8.34; P < .001), especially cerebrovascular events (aOR, 22.00; 95% CI, 15.25-31.72; P < .001) and thromboembolism (aOR, 17.34; 95% CI, 11.55-26.03; P < .001). Racial disparities explained a median (IQR) 28.9% (21.2%-33.1%) of the increased risk in deliveries to people with SCD and between 40% and 50% of the increased risk for acute kidney failure (excess risk [ER], 56.9%; 95% CI, 54.3%-59.3%), intrauterine fetal demise (ER, 47.8%; 95% CI, 46.6%-49.1%), and eclampsia (ER, 42.1%; 95% CI, 37.9%-46.1%).

CONCLUSIONS AND RELEVANCE

In this large cross-sectional study of pregnancy outcomes in people with SCD, the risk for SMM was higher compared with deliveries among people without SCD, especially for thrombotic events, organ failure, and death. Racial disparities were associated with adverse outcomes. Our findings compel scientific, clinical, and political effort to improve outcomes for pregnant people with SCD.

Evidence-based management of pregnant women with sickle cell disease in high-income countries

Globally, patients living with sickle cell disease are now surviving to reproductive age, with life expectancy approaching 50 years in most countries. Thus, reproductive options are now essential for patients living with the condition. However, it can be associated with maternal, delivery, and fetal complications. Outcomes may vary depending on the level of expertise and resources. In this piece we provide an optional guideline for managing sickle cell disease in pregnancy. The therapeutic option of serial exchange prophylactic transfusion has been offered in the context of a clinical trial (TAPS2).

Indications for transfusion in the management of sickle cell disease

The transfusion of red blood cells (RBCs) is a crucial treatment for sickle cell disease (SCD). While often beneficial, the frequent use of transfusions is associated with numerous complications. Transfusions should be offered with specific guidelines in mind. Here we present updates to the indications for transfusion of RBCs in SCD. We review recent publications and include expert perspectives from hematology and transfusion medicine. For some clinical indications, such as ischemic stroke, the role of transfusion has been well studied and can be applied almost universally. For many other clinical scenarios, the use of transfusion therapy has less conclusive data and therefore must be tailored to individual needs. We highlight the roles of RBC transfusions in preventing or mitigating neurological disease, in reducing perioperative complications, in managing acute chest syndrome, and in optimizing pregnancy outcomes in SCD. We further highlight various transfusion techniques and when each might be considered. Potential complications of transfusion are also briefly discussed.

Perinatal outcomes in women with sickle cell disease: a matched cohort study from London, UK

There are limited data on contemporary outcomes for women with sickle cell disease (SCD) in pregnancy. We conducted a single-site matched cohort study, comparing 131 pregnancies to women with SCD between 2007 and 2017 to a comparison group of 1310 pregnancies unaffected by SCD. Restricting our analysis to singleton pregnancies that reached 24 weeks of gestation, we used conditional Poisson regression to estimate adjusted risk ratios (aRRs) for perinatal outcomes. Infants born to mothers with SCD were more likely to be small for gestational age [aRR 1·69, 95% confidence interval (CI) 1·13-2·48], preterm (aRR 2·62, 95% CI 1·82-3·78) and require Neonatal Unit (NNU) admission (aRR 3·59, 95% CI 2·18-5·90). Pregnant women with SCD were at higher risk of pre-eclampsia/eclampsia (aRR 3·53, 95% CI 2·00-6·24), more likely to receive induction of labour (aRR 2·50, 95% CI 1·82-1·76) and caesarean birth (aRR 1·44, 95% CI 1·18-1·76). In analysis stratified by genotype, the risk of adverse outcomes was highest in haemoglobin SS (HbSS) pregnancies (n = 80). There was no strong evidence that haemoglobin SC (HbSC) pregnancies (n = 46) were at higher risk of preterm birth, caesarean delivery, or NNU admission. Pre-eclampsia/eclampsia was more frequently observed in HbSC pregnancies. Despite improvements in the care of pregnant women with SCD, the increased risk of adverse perinatal outcomes remains.

Pregnancies and Neonatal Outcomes in Patients with Sickle Cell Disease (SCD): Still a (High-)Risk Constellation?

Background: This monocentric study conducted at the University Hospital of Essen aims to describe maternal and fetal/neonatal outcomes in sickle cell disease (SCD) documented between 1996 to 2021 (N = 53), reflecting the largest monocentric analysis carried out in Germany. Methods/Results: 46 pregnancies in 22 patients were followed. None of the patients died. In total, 35% (11/31) of pregnancies were preterm. 15 pregnancies in eight patients were conceived on hydroxycarbamide (HC), of which nine had a successful outcome and three were terminated prematurely. There was no difference regarding the rate of spontaneous abortions in patients receiving HC compared to HC-naive patients prior to conception. In patients other than HbS/C disease, pregnancies were complicated by vaso-occlusive crises (VOCs)/acute pain crises (APCs) (96%, 23/24); acute chest syndrome (ACS) (13%, 3/24), transfusion demand (79%, 19/24), urinary tract infections (UTIs) (42%, 10/24) and thromboembolic events (8%, 2/24). In HbS/C patients complications included: VOCs/APCs (43%, 3/7; ACS: 14%, 1/7), transfusion demand (14%, 1/7), and UTIs (14%, 1/7). Independent of preterm deliveries, a significant difference with respect to neonatal growth in favor of neonates from HbS/C mothers was observed. Conclusion: Our data support the results of previous studies, highlighting the high rate of maternal and fetal/neonatal complications in pregnant SCD patients.