Transfusion Medicine and the Pregnant Patient

Peripartum Blood Transfusions are Associated with Increased Risk of Cancer: A National Retrospective Cohort Study

Background

The effect of blood transfusions on the risk of developing primary cancer remains unclear, especially when administered in the peripartum period.

Materials and Methods

We conducted a retrospective cohort study of 270,529 pregnant women who delivered between January 1, 2007 and December 31, 2009, with data obtained from three national databases in South Korea. From this cohort, we identified 4569 patients who received peripartum blood transfusions. We calculated hazard ratios (HRs) for new diagnoses of cancer and adjusted them for relevant clinical factors using a Cox proportional hazards model.

Results

During follow-up, patients who received peripartum transfusions had an increased risk of developing cancer, with an adjusted HR of 1.16 (95% confidence interval [CI], 1.01–1.34). In a subgroup analysis, this risk was significant only among patients who received 3 or more units of blood, with an adjusted HR of 1.40 (95% CI, 1.10–1.79). Increased risk after transfusions were seen with brain, lung, ovarian, and gallbladder cancers. The difference in cancer risk between the transfusion and no-transfusion groups remained significant during both the first (1.29% vs 1.07%, p < 0.01) and second year (0.74% vs 0.56%, p < 0.01) after delivery.

Conclusion

Receipt of 3 or more blood transfusions in the peripartum period was associated with a significantly increased risk of developing cancer. Prospective studies should be pursued to further understand the link between blood transfusions and long-term oncologic risks.

Identification and follow-up of pregnant women with platelet-type human platelet antigen (HPA)-1bb alloimmunized with fetal HPA-1a

INTRODUCTION

Pregnant women negative for human platelet antigen 1a (HPA-1a) are at risk of alloimmunization with fetal HPA-1a antigen inherited from the father, and their offspring may develop fetal and neonatal alloimmune thrombocytopenia (FNAIT). The aim of this study was to analyze the frequency of HPA-1a alloimmunization in pregnant Polish women, the feasibility of using maternal platelets for intrauterine transfusions in women subjected to diagnostic fetal blood sampling (FBS) and to discuss potential consequences of alloimmunization.

MATERIAL AND METHODS

Fifteen thousand two hundred and four pregnant women were typed for HPA-1a; HPA-1a negative were screened for anti-HPA-1a. Alloimmunized women received specialist perinatology care; some of them were subjected to FBS, followed by transfusion of HPA-1a negative platelet concentrates (PC) prepared from maternal blood.

RESULTS

Three hundred seventy-three (2.5%) women were HPA-1a negative, and 32 (8.6%) tested positively for anti-HPA-1a. Antibodies were detected in 22 women during pregnancy. Diagnostic FBS followed by PC transfusion was performed in 14 woman, who were platelet donors for their 16 unborn babies. Blood donations were tolerated well by the patients, and also intrauterine platelet transfusions were uneventful. Pharmacotherapy with intravenous immunoglobulins was implemented in 11/22 patients.

CONCLUSIONS

HPA-1a negative women (ca. 2.5% of all pregnant patients) are at risk of alloimmunization with HPA-1a antigen and developing FNAIT. Alloimmunized women can be donors of platelets for their offspring providing removal of antibodies from PC. Owing to potential complications, special care should be taken if an alloimmunized woman was qualified as a blood or stem cell recipient.

Mild-to-moderate foeto-maternal haemorrhage in the third trimester and at term of pregnancy: quantitative determination and clinical-diagnostic evaluation

BACKGROUND

Foeto-maternal haemorrhage (FMH), a gestational event that occurs before or during delivery, consists of a loss of foetal blood into the maternal circulation. FMH occurs more frequently during the third trimester or labour both in normal and complicated pregnancies. In the case of alloimmunisation, the maternal immunological response and the severity of the resulting foetal or neonatal disease depend on the amount of foetal blood that passes into the maternal circulation. The aim of this study was to determine FMH in the third trimester and at term of pregnancy and to evaluate the role of clinical and ultrasound markers in the prediction of FMH.

MATERIALS AND METHODS

FMH was quantified by cytofluorimetric testing at 28 to 35 weeks of gestation in 223 women and at term in 465 women, all with risk factors. Foetal evaluation included foetal movement profile, middle cerebral artery peak velocity of systolic blood flow (MCA-PSV) and cardiotocographic monitoring.

RESULTS

All women tested negative for FMH in the third trimester. Four patients (0.9%) tested positive at term, with estimated volumes of bleeding of 2.2, 8.1, 12.3 and 39.8 mL. Three FMH cases (75%) had a non-reassuring cardiotocography compared to 8.9% (42/461) of women without FMH (p=0.003) and two FMH cases reported a reduction in foetal movements reduction compared to four of those without FMH (p=0.001). Mean MCA-PSV was normal in both the groups with and without FMH (p=0.22).

DISCUSSION

FMH is rare in pregnancy and at term. Cytofluorimetric testing is a specific method to detect mild-to-moderate FMH even when the MCA-PSV is not informative. Mild-to-moderate FMH is significantly associated with reduced foetal movements and non-reassuring cardiotocographic monitoring.

Chimerism in transfusion medicine: the grandmother effect revisited

Transfusion therapy is complicated by the production of alloantibodies to antigens present in the donor and lacking in the recipient through the poorly-understood but likely multi-factorial process of alloimmunization. The low prevalence of alloimmunization in transfused patients (6.1%) (1) suggests that processes central to immunologic tolerance may be operating in the vast majority of transfused patients who do not produce alloantibodies. Using RhD as a prototype, evidence is reviewed that the ability to make antibodies to red blood cell (RBC) antigens may result in part from immunologic tolerance acquired in utero. These ideas are extended to other examples of maternal microchimerism (MMc) of other non-inherited maternal antigens (NIMA). An evolutionary argument is offered that multi-generational immunity supports the hypothesis that MMc may partly explain the "non-responder" phenotype in RBC alloimmunization.

Pregnancy with a severe hemoglobinopathy: unintended consequences of transfusions

We report a case of a pregnant woman with a complex hemoglobinopathy who developed a symptomatic anemia at 28 weeks of gestation and was treated with multiple transfusions of type-specific packed red blood cells. Shortly thereafter, she developed a fever and joint pains, along with laboratory values consistent with hemolysis. Timing suggested a delayed transfusion reaction. An extensive evaluation including red blood cell antigen identification and cross-reaction failed to reveal the cause for her hemolysis. Despite her critically low hemoglobin levels, her transfusions were withheld in an attempt to allow the patient to recover conservatively. With this strategy, her hemoglobin remained below her baseline, but her symptoms began to improve. Her laboratory values normalized, and hemolysis was no longer evident. Three weeks later, her hemoglobin levels returned back to her baseline without additional intervention. She went on to deliver a full-term male infant.