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. The present review replaces and updates a Cochrane review that was withdrawn in 2006.
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 (31 October 2013) and reference lists of retrieved studies. We did not apply any language restrictions. SELECTION CRITERIA: Randomised and quasi-randomised trials evaluating the effects of prophylactic versus selective (emergency) blood transfusion in pregnant women with sickle cell disease. Trials were considered for inclusion whether the unit of randomisation was at individual or cluster level, however, no cluster-randomised trials were identified. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and assessed trial quality. Two review authors independently extracted data. Data were checked for accuracy. MAIN
RESULTS: Out of six relevant reports identified by the search strategy, two trials involving 98 women with sickle cell anaemia (HbSS) met our inclusion criteria. The two trials were at moderate risk of bias. Overall, there were few events for most of the reported outcomes and the results were generally imprecise. One trial (involving 72 women) reported no maternal mortality occurring in women who received either prophylactic or selective blood transfusion. The same trial (involving 72 women) indicated no clear differences in maternal mortality, perinatal mortality (risk ratio (RR) 2.85, 95% confidence interval (CI) 0.61 to 13.22) or markers of severe maternal morbidity [pulmonary embolism (no events); congestive cardiac failure (RR 1.00, 95% CI 0.07 to 15.38); acute chest syndrome (RR 0.67, 95% CI 0.12 to 3.75)] between the treatment groups (prophylactic blood transfusion versus selective blood transfusion). Prophylactic blood transfusion reduced the risk of pain crisis compared with selective blood transfusion (RR 0.42, 95% CI 0.17 to 0.99, two trials, 98 women); however, the margin of uncertainty around the effect estimate ranged from very small to substantial reduction. One trial (involving 72 women) indicated no differences in the occurrence of acute splenic sequestration (RR 0.33, 95% CI 0.01 to 7.92) and haemolytic crises (RR 0.33, 95% CI 0.04 to 3.06) and delayed blood transfusion reaction (RR 2.00, 95% CI 0.54 to 7.39) between the comparison groups. AUTHORS'
CONCLUSIONS: Evidence from two small trials of 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.