Prophylactic versus selective blood transfusion for sickle cell disease in pregnancy

Maternal and perinatal outcomes in pregnant women with sickle cell disease: an update

INTRODUCTION

The aim of this study was to describe maternal and perinatal outcomes in pregnant women with sickle cell disease (SCD) followed at Santa Casa de Sao Paulo over a 10-year period (between 2010 and 2019).

METHOD

Fifty-five records of pregnancies were analyzed among 35 women with SCD.

RESULTS

Among 29 newborns, 19 (65.5%) were full-term and 10 pre-term; 24 (82.7%) caesareans and 5 (17.2%) natural births were observed. The mean gestational age at birth and mother`s age were 36.6 weeks (30-40) and 26.7 years (17-39), respectively. No maternal death was observed. The main maternal obstetric and non-obstetric complications were: pre-eclampsia and gestational diabetes, and vaso-occlusive crisis, urinary tract infection and acute chest syndrome, respectively. Twenty-six (47.0%) fetal deaths were observed, 24 being intrauterine fetal (14 early abortions, 10 late abortions and 2 stillbirths). Regarding the red blood cell transfusion history, 40 (72.7%) out of 55 pregnancies received transfusion. Pregnant women who received 6 or more transfusions throughout pregnancy had a significantly lower number of abortions, i.e., no cases of early abortion and only 1 case of late abortion, versus 14 and 9 cases in pregnancies with 0-5 transfusions, respectively. Despite advances in the management of SCD, pregnant women with SCD (particularly those with HbSS) are at a high risk for maternal and fetal complications, even though they are followed in reference centers.

CONCLUSION

The lower risk of intrauterine fetal death for those women who received more transfusions throughout pregnancy observed in the current study leads us once more to raise the need for prospective, multicenter, randomized trials to determine whether the potential benefits balance the risks of prophylactic transfusions.

Prophylactic versus selective blood transfusion for sickle cell disease in pregnancy

BACKGROUND

Pregnant women with sickle cell disease (HbSS, HbSC and HbSβThal) may require blood transfusion to prevent severe anaemia or to manage potential medical complications. Preventive blood transfusion in the absence of complications starting from the early weeks of pregnancy or blood transfusion only for medical or obstetric indications have been used as management policies. There is currently no consensus on the blood transfusion policy that guarantees optimal clinical benefits with minimal risks for such women and their babies. This is an update of a Cochrane review that was published in 2013.

OBJECTIVES

To assess the benefits and harms of a policy of prophylactic versus selective blood transfusion in pregnant women with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 May 2016) and reference lists of retrieved studies. We did not apply any language or date restrictions.

SELECTION CRITERIA

Randomised controlled trials evaluating the effects of prophylactic versus selective (emergency) blood transfusion in pregnant women with sickle cell disease (SCD). Quasi-randomised trials and trials using a cluster-randomised design were eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. Two review authors independently assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

Out of six relevant reports identified by the search strategy, one trial involving 72 women with sickle cell anaemia (HbSS) met our inclusion criteria. The trial was at unclear risk of bias. Overall, there were few events for most of the reported outcomes and the results were generally imprecise. The included trial reported no maternal mortality occurring in women who received either prophylactic or selective blood transfusion. Very low-quality evidence indicated no clear differences in maternal mortality, perinatal mortality (risk ratio (RR) 2.85, 95% confidence interval (CI) 0.61 to 13.22; very low-quality evidence) or markers of severe maternal morbidity (pulmonary embolism (no events); congestive cardiac failure (RR 1.00, 95% CI 0.07 to 15.38; very low-quality evidence); acute chest syndrome (RR 0.67, 95% CI 0.12 to 3.75)) between the treatment groups (prophylactic blood transfusion versus selective blood transfusion). Low-quality evidence indicated that prophylactic blood transfusion reduced the risk of pain crisis compared with selective blood transfusion (RR 0.28, 95% CI 0.12 to 0.67, one trial, 72 women; low-quality evidence), and no differences in the occurrence of acute splenic sequestration (RR 0.33, 95% CI 0.01 to 7.92; low-quality evidence), haemolytic crises (RR 0.33, 95% CI 0.04 to 3.06) or delayed blood transfusion reaction (RR 2.00, 95% CI 0.54 to 7.39; very low-quality evidence) between the comparison groups.Other relevant maternal outcomes pre-specified for this review such as cumulative duration of hospital stay, postpartum haemorrhage and iron overload, and infant outcomes, admission to neonatal intensive care unit (NICU) and haemolytic disease of the newborn, were not reported by the trial.

AUTHORS' CONCLUSIONS

Evidence from one small trial of very low quality suggests that prophylactic blood transfusion to pregnant women with sickle cell anaemia (HbSS) confers no clear clinical benefits when compared with selective transfusion. Currently, there is no evidence from randomised or quasi-randomised trials to provide reliable advice on the optimal blood transfusion policy for women with other variants of sickle cell disease (i.e. HbSC and HbSβThal). The available data and quality of evidence on this subject are insufficient to advocate for a change in existing clinical practice and policy.