FIGO/ICM guidelines for preventing Rhesus disease: A call to action

[Prevention of Rh D alloimmunization in the first trimester of the pregnancy: French College of Obstetricians and Gynecologists guidelines for clinical practice]

OBJECTIVE

To provide recommendations for the prevention of Rh D alloimmunization in the first trimester of pregnancy.

MATERIALS AND METHODS

The quality of evidence of the literature was assessed following the GRADE methodology with questions formulated in the PICO format (Patients, Intervention, Comparison, Outcome) and outcomes defined a priori and classified according to their importance. An extensive bibliographic search was performed on Pubmed, Cochrane, EMBASE, and Google Scholar databases. The quality of evidence was assessed (high, moderate, low, very low) and a recommendation was formulated: (i) strong, (ii) weak, or (iii) no recommendation. The recommendations were reviewed in two rounds with reviewers from the scientific board of the French College of the OB/GYN (Delphi survey) to select the consensus recommendations.

RESULTS

The three recommendations from PICO questions reached agreement using the Delphi method. It is recommended not to administer Rh D immunoglobulin before 12 weeks of gestation to reduce the risk of alloimmunization in case of abortion or miscarriage, in RhD negative patients when the genitor is RhD positive or unknown (Weak recommendation. Very low-quality evidence). It is recommended not to administer Rh D immunoglobulin before 12 weeks of gestation to reduce the risk of alloimmunization in cases of bleeding in an ongoing intrauterine pregnancy (Weak recommendation. Very low-quality evidence). The literature data are insufficient in quality and quantity to determine if the injection of Rh D immunoglobulin reduces the risk of alloimmunization in the case of an ectopic pregnancy (No recommendation. Very low-quality evidence).

CONCLUSION

Even though the quality of evidence from the studies is very low, it is recommended not to administer Rh D immunoglobulin in case of abortion, miscarriage or bleeding before 12 weeks of amenorrhea. The quality of evidence was too low to issue a recommendation regarding ectopic pregnancy.

Society for Maternal-Fetal Medicine Statement: RhD immune globulin after spontaneous or induced abortion at less than 12 weeks of gestation

Guidelines for the management of first-trimester spontaneous and induced abortion vary in terms of rhesus factor D (RhD) testing and RhD immune globulin (RhIg) administration. These existing guidelines are based on limited data that do not convincingly demonstrate the safety of withholding RhIg for first-trimester abortions or pregnancy losses. Given the adverse fetal and neonatal outcomes associated with RhD alloimmunization, prevention of maternal sensitization is essential in RhD-negative patients who may experience subsequent pregnancies. In care settings in which RhD testing and RhIg administration are logistically and financially feasible and do not hinder access to abortion care, we recommend offering both RhD testing and RhIg administration for spontaneous and induced abortion at <12 weeks of gestation in unsensitized, RhD-negative individuals. Guidelines for RhD testing and RhIg administration in the first trimester must balance the prevention of alloimmunization with the individual- and population-level harms of restricted access to abortion.

Antenatal RHD screening to guide antenatal anti-D immunoprophylaxis in non-immunized D- pregnant women

In pregnancy, D- pregnant women may be at risk of becoming immunized against D when carrying a D+ fetus, which may eventually lead to hemolytic disease of the fetus and newborn. Administrating antenatal and postnatal anti-D immunoglobulin prophylaxis decreases the risk of immunization substantially. Noninvasive fetal RHD genotyping, based on testing cell-free DNA extracted from maternal plasma, offers a reliable tool to predict the fetal RhD phenotype during pregnancy. Used as a screening program, antenatal RHD screening can guide the administration of antenatal prophylaxis in non-immunized D- pregnant women so that unnecessary prophylaxis is avoided in those women who carry a D- fetus. In Europe, antenatal RHD screening programs have been running since 2009, demonstrating high test accuracies and program feasibility. In this review, an overview is provided of current state-of-the-art antenatal RHD screening, which includes discussions on the rationale for its implementation, methodology, detection strategies, and test performance. The performance of antenatal RHD screening in a routine setting is characterized by high accuracy, with a high diagnostic sensitivity of ≥99.9 percent. The result of using antenatal RHD screening is that 97-99 percent of the women who carry a D- fetus avoid unnecessary prophylaxis. As such, this activity contributes to avoiding unnecessary treatment and saves valuable anti-D immunoglobulin, which has a shortage worldwide. The main challenges for a reliable noninvasive fetal RHD genotyping assay are low cell-free DNA levels, the genetics of the Rh blood group system, and choosing an appropriate detection strategy for an admixed population. In many parts of the world, however, the main challenge is to improve the basic care for D- pregnant women.

Prevention of Rhesus-D Alloimmunization in the First Trimester of Pregnancy: Economic Analysis of Three Management Strategies

Anti-D alloimmunization in the first trimester of pregnancy has long been the subject of prevention with anti-D immunoglobulins during events at risk of fetomaternal hemorrhage. Although the efficacy of preventing anti-D alloimmunization by an injection of immunoglobulin at 28 weeks of gestation (WG) is obvious, the literature provides little evidence of the effectiveness before 12+6 WG and several countries have modified their recommendations. In the presumed absence of a difference in alloimmunization risk between early and late prevention, our objective was to evaluate and compare the cost of treatment for 3 alloimmunization prevention strategies in France, the United Kingdom, and the Netherlands. This was a single-center retrospective study. Our target population included all women who received anti-D immunoglobulins (Rhophylac) in the first trimester of pregnancy before 12+6 WG at Nantes University Hospital in 2018 (N = 356). Within the target population, 2 other populations were constituted based on British (N = 145) and Dutch (N = 142) clinical practice guidelines (CPG). These 3 populations were analyzed for the comparative cost of treatment for prevention from a health system perspective. The average cost of Rhophylac alloimmunization prevention for 1 episode was €117.8 from a health system perspective. The total cost attributed to prevention in 2018 at Nantes University Hospital (N = 356) was €41,931.4 according to this perspective. If the UK CPG or Dutch CPG had been applied to the Nantes target population, a saving of around 60% would have been achieved. At the national level, the cost according to the health system perspective specifically attributable to induced abortion (N estimated = 26,916) could represent a total cost of €3,170,704. This study highlighted the high cost of the French prevention strategy in the first trimester of pregnancy compared with British or Dutch strategies. The modification of our practices would allow substantial financial savings to the French health system but would also avoid the nonrecommended exposure to a blood product at this term, would allow a faster medical management and a relief of the care system.

Hemolytic disease of the fetus and newborn: rapid review of postnatal care and outcomes

BACKGROUND

Advances in postnatal care for hemolytic disease of the fetus and newborn (HDFN) have occurred over the past decades, but little is known regarding the frequency of postnatal treatment and the clinical outcomes of affected neonates. Most studies reporting on HDFN originate from high-income countries or relatively large centers, but important differences between centers and countries may exist due to differences in prevalence and available treatment options. We therefore aimed to evaluate the postnatal treatment landscape and clinical outcomes in neonates with Rhesus factor D (Rh(D))- and/or K-mediated HDFN and to provide recommendations for future research.

METHODS

We conducted a rapid literature review of case reports and series, observational retrospective and prospective cohort studies, and trials describing pregnancies or children affected by Rh(D)- or K-mediated HDFN published between 2005 and 2021. Information relevant to the treatment of HDFN and clinical outcomes was extracted. Medline, ClinicalTrials.gov and EMBASE were searched for relevant studies by two independent reviewers through title/abstract and full-text screening. Two independent reviewers extracted data and assessed methodological quality of included studies.

RESULTS

Forty-three studies reporting postnatal data were included. The median frequency of exchange transfusions was 6.0% [interquartile range (IQR): 0.0-20.0] in K-mediated HDFN and 26.5% [IQR: 18.0-42.9] in Rh(D)-mediated HDFN. The median use of simple red blood cell transfusions in K-mediated HDFN was 50.0% [IQR: 25.0-56.0] and 60.0% [IQR: 20.0-72.0] in Rh(D)-mediated HDFN. Large differences in transfusion rates were found between centers. Neonatal mortality amongst cases treated with intrauterine transfusion(s) was 1.2% [IQR: 0-4.4]. Guidelines and thresholds for exchange transfusions and simple RBC transfusions were reported in 50% of studies.

CONCLUSION

Most included studies were from middle- to high-income countries. No studies with a higher level of evidence from centers in low-income countries were available. We noted a shortage and inconsistency in the reporting of relevant data and provide recommendations for future reports. Although large variations between studies was found and information was often missing, analysis showed that the postnatal burden of HDFN, including need for neonatal interventions, remains high.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2021 CRD42021234940. Available from:  https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021234940 .

Ectopic pregnancy: search for biomarker in salivary proteome

Ectopic pregnancy (EP) is associated with high maternal morbidity and mortality. Ultrasonography is the only dependable diagnostic tool for confirming an ectopic pregnancy. In view of inadequate early detection methods, women suffer from a high-life risk due to the severity of EP. Early detection of EP using pathological/molecular markers will possibly improve clinical diagnosis and patient management. Salivary proteins contain potential biomarkers for diagnosing and detecting various physiological and/or pathological conditions. Therefore, the present investigation was designed to explore the salivary proteome with special reference to EP. Gel-based protein separation was performed on saliva, followed by identification of proteins using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Totally, 326 proteins were identified in the salivary samples, among which 101 were found to be specific for ruptured ectopic pregnancy (EPR). Reactome analysis revealed innate immune system, neutrophil degranulation, cell surface interactions at the vascular wall, and FCERI-mediated NF-kB activation as the major pathways to which the salivary proteins identified during EPR are associated. Glutathione-S-transferase omega-1 (GSTO1) is specific for EPR and has been reported as a candidate biomarker in the serum of EPR patients. Therefore, saliva would be a potential source of diagnostic non-invasive protein biomarker(s) for EP. Intensive investigation on the salivary proteins specific to EP can potentially lead to setting up of a panel of candidate biomarkers and developing a non-invasive protein-based diagnostic kit.

Rh(D) immune globulin administration in pregnancy: Retrospective audit of patient safety events followed by targeted educational intervention with Bayesian analysis

OBJECTIVES

To examine local patient safety events related to the administration of anti-Rh(D) immune globin (RhIG) during pregnancy, and to follow-up with targeted educational intervention to improve knowledge of this process.

BACKGROUND

Administration RhIG is established treatment for the prevention of haemolytic disease of the foetus and newborn (HDFN). However, patient safety events in relation to its correct use continue to occur.

METHODS

A retrospective audit of patient safety events related to RhIG administration during pregnancy was performed. Targeted educational intervention in the form of PowerPoint® presentation were given to nursing staff, laboratory staff and physicians and evaluated with pre- and post-tests using multiple-choice questions given immediately before and after the presentation.

RESULTS

An annual incidence of 0.24% of patient safety events related to the administration of RhIG during pregnancy was found. These events were mostly in the preanalytical phase, for example mislabelled samples or samples for D-rosette/Kleihauer-Betke testing drawn from the baby, not the mother. Using Bayesian analysis, the probability of positive effect for the targeted educational intervention was 100% with a median improved score of 29%. This was compared with a control group using standard curriculum education intervention based on the current curriculum for nursing, laboratory and medical students which showed a median improved score of only 4.4%.

CONCLUSIONS

Administration of RhIG during pregnancy is a multistep process involving health care professionals of several disciplines providing opportunities to enhance the curriculum for nursing, laboratory and medical students and to ensure on-going education.

Case report: Double filtration plasmapheresis (DFPP) for severe rhesus-D alloimmunization in two pregnant patients

Maternal erythrocyte alloimmunization is one of the most important causes of fetal anemia. The standard treatment for anemic fetuses is intrauterine blood transfusion (IUT). However, IUT may have adverse effects, particularly before 20 weeks of gestation. In this report, two women who had previously had severely affected alloimmunized pregnancy developed high titers of anti-D antibodies before 20 weeks of gestation. Ultrasound Doppler showed severe fetal anemia, and intrauterine transfusion was expected to be unavoidable. To prolong pregnancy to a gestation in which intravascular IUT was possible, we used repeated double filtration plasmapheresis (DFPP) as a rescue therapy. The titers of IgG-D, IgG-A, and IgG-B decreased after DFPP treatment. One woman successfully prolonged pregnancy until 20 weeks of gestation. Subsequently, she underwent four cycles of IUTs and delivered at 30 weeks of gestation by emergency cesarean section due to fetal bradycardia during the fifth intrauterine transfusion. The other woman successfully delayed intrauterine transfusion until 26 weeks of gestation. The favorable results of the two patients indicate that DFPP may be an effective and safe treatment modality for RhD immunity in pregnant women. Moreover, DFPP is potentially helpful for reducing the occurrence of ABO hemolytic disease in neonates due to the clearance of IgG-A and IgG-B antibodies (e.g., O pregnant women harbored A/B/AB neonates). However, more clinical trials are needed to verify the results.

The basics of blood and associated disorders

The blood and its components are involved in a wide range of processes to support life, including fighting infection and providing the body's tissues with oxygen and nutrients. If any stage in the development of blood cells is disrupted, for example by genetic abnormalities or a lack of nutrients, disease may result. This article provides an overview of some of the blood's key components, blood cells and their formation and functions, blood groups and some of the problems that can arise from malfunctions. A case study on haemophilia A as a blood disorder is presented to consolidate knowledge.

Identification and management of fetal anemia due to hemolytic disease

INTRODUCTION

Hemolytic disease of the fetus and newborn (HDFN) is a condition caused by maternal alloantibodies against fetal red blood cells (RBCs) that can cause severe morbidity and mortality in the fetus and newborn. Adequate screening programs allow for timely prevention and intervention resulting in significant reduction of the disease over the last decades. Nevertheless, HDFN still occurs and with current treatment having reached an optimum, focus shifts toward noninvasive therapy options.

AREAS COVERED

This review focusses on the timely identification of high risk cases and antenatal management. Furthermore, we elaborate on future perspectives including improvement of screening, identification of high risk cases and promising treatment options.

EXPERT OPINION

In high-income countries mortality and morbidity rates due to HDFN have drastically been reduced over the last decades, yet worldwide anti-D mediated HDFN still accounts for 160,000 perinatal deaths and 100,000 patients with disabilities every year. Much of these deaths and disabilities could have been avoided with proper identification and prophylaxis. By implementing sustainable prevention, screening, and disease treatment measures in all countries this will systemically reduce unnecessary perinatal deaths. There is a common responsibility to engage in this cause.

An overview of red blood cell and platelet alloimmunisation in transfusion

Post-transfusion alloimmunisation is the main complication of all those observed after one or more transfusion episodes. Alloimmunisation is observed after the transfusion of red blood cell concentrates but also of platelet concentrates. Besides alloimmunisation due to antigens carried almost exclusively by red blood cells such as those of the Rhesus-Kell system, alloimmunisation often raises against HLA antigens; the main responsibility for that, apart from platelet transfusions, lies with residual leukocytes in the products transfused, hence the central importance of effective leukoreduction right from the blood product preparation stage. Alloimmunization is not restricted to transfusion, but it is also observed during pregnancies, carrying out microtransfusions of blood from the fetus immunizing the mother through the placenta (in a retrograde way). Preexisting maternal-fetal immunization can complicate a transfusion program and intensify the creation of alloantibodies in several blood and tissue group systems. The occurrence of autoantibodies, created by several pathogenic reasons, can also interfere with the propensity of certain recipients of blood components to produce alloantibodies. The genetic condition of individuals is in fact strongly linked to the ability or not to recognize antigenic variants foreign to their own biological program and mount an alloimmune response. Some hemoglobin diseases, in carriers of which transfusions can be iterative and lifelong, are complicated by frequent alloimmunizations and amplification of the complications of these alloimmunizations, imposing even stricter transfusion rules. This review details the mechanisms favoring the occurrence of alloimmunization and the immunological principles for the production of molecular and cellular tools for alloimmunization. It concludes with the main preventive measures available to limit the occurrence of these frequent complications of varying severity but sometimes severe.

Practices for RhD alloimmunization prevention: a vignette-based survey of midwives

INTRODUCTION

Despite the availability guidelines to prevent RhD alloimmunization, severe hemolytic disease of fetus and newborn still occurs in high-income countries. The aim of the study was (1) To assess variations in practices for the prevention of RhD alloimmunization, and (2) to understand midwives' acceptance and appropriation of fetal RhD genotyping.

METHODS

Descriptive cross-sectional survey of French midwives from September 2017 through January 2018. Participants were asked to complete an internet-based questionnaire that included three clinical vignettes. They were questioned about their practices concerning early pregnancy visit by RhD-negative women, prevention of RhD alloimmunization in women with second-trimester metrorrhagia, and RhD fetal genotyping.

RESULTS

A total of 827 midwives completed the questionnaire. Only 21.1% reported that they practice all the preventive measures recommended in early pregnancy. In a situation at high risk of RhD alloimmunization during pregnancy, 97.2% of midwives would perform immunoprophylaxis. Nearly, all midwives reported providing information about RhD alloimmunization (92.4%) at the beginning of pregnancy, although only 11.3% offered both written and verbal information; at the time of systematic anti-D immunoprophylaxis (28 weeks), 78% provided information, but only 2.7% both verbally and in writing. Finally, only 50.8% of midwives preferred to include RhD fetal genotyping in routine prenatal prophylaxis.

DISCUSSION

This study showed significant variations in French midwives' practices to prevent RhD alloimmunization. Better dissemination of guidelines is needed to improve both consistent use of these practices and the quality of information delivered to RhD-negative pregnant women.