Appropriate provision of anti-D prophylaxis to RhD negative pregnant women: a scoping review

An ongoing problem: Rhesus hemolytic disease of the newborn - A decade of experience in a single centre

BACKGROUND

The objectives were to evaluate the descriptive features of newborns with a diagnosis of Rhesus (Rh) hemolytic disease, to determine the morbidity and mortality rates, to evaluate the treatment methods and the factors affecting treatment requirements and clinical outcomes during a ten-year period at a tertiary center.

METHODS

Newborn infants who had a positive direct Coombs test and/or had a history of intrauterine transfusion (IUT) due to Rh hemolytic disease were included. The data regarding the prenatal, natal and postnatal periods were collected from hospital records.

RESULTS

A total of 260 neonates were included of which 51.2% were female. The mean ± standard deviation gestational age was 36.9 ± 2.7 weeks. The rate of preterm birth was 41.2%. Of 257 mothers whose obstetric medical history could be accessed, 87.2% were multigravida, whereas 76.3% were multiparous. Among mothers who had a reliable history of anti-D immunoglobulin prophylaxis (n=191), 51.3% had not received anti-D immunoglobulin prophylaxis in their previous pregnancies. The antenatal transfusion rate was 31.7% and the frequency of hydrops fetalis was 8.8%. While combined exchange transfusion (ET) and phototherapy (PT) was performed in 15.4% of the babies, the majority either needed phototherapy only (51.1%) or no treatment (33.5%). The mortality rate was 3.8 % (n = 10), and nine babies out of these 10 were those with severe hydrops fetalis.

CONCLUSION

This study showed that Rh hemolytic disease is still a major problem in developing countries. Multiple comorbidities may occur in addition to life threatening complications, including hydrops fetalis, anemia and severe hyperbilirubinemia. High rates of multiparity and low rates of anti-D immunoglobulin prophylaxis are potential barriers for the eradication of the disease. It should be remembered that Rh hemolytic disease is a preventable disease in the presence of appropriate antenatal follow-up and care facilities.

What are the essential components of antenatal care? A systematic review of the literature and development of signal functions to guide monitoring and evaluation

BACKGROUND

Antenatal care (ANC) is one of the key care packages required to reduce global maternal and perinatal mortality and morbidity.

OBJECTIVES

To identify the essential components of ANC and develop signal functions.

SEARCH STRATEGY

MESH headings for databases including Cinahl, Cochrane, Global Health, Medline, PubMed and Web of Science.

SELECTION CRITERIA

Papers and reports on content of ANC published from 2000 to 2020.

DATA COLLECTION AND ANALYSIS

Narrative synthesis of data and development of signal function through 7 consensus-building workshops with 184 stakeholders.

MAIN RESULTS

A total of 221 papers and reports are included from which 28 essential components of ANC were extracted and used to develop 15 signal functions with the equipment, medication and consumables required for implementation of each. Signal functions for the prevention and management of infectious diseases (malaria, HIV, tuberculosis, syphilis and tetanus) can be applied depending on population disease burden. Screening and management of pre-eclampsia, gestational diabetes, anaemia, mental and social health (including intimate partner violence) are recommended universally. Three signal functions address monitoring of fetal growth and wellbeing, and identification and management of obstetric complications. Promotion of health and wellbeing via education and support for nutrition, cessation of substance abuse, uptake of family planning, recognition of danger signs and birth preparedness are included as essential components of ANC.

CONCLUSIONS

New signal functions have been developed which can be used for monitoring and evaluation of content and quality of ANC. Country adaptation and validation is recommended.

Peak systolic velocity of fetal middle cerebral artery to predict anemia in Red Cell Alloimmunization in un-transfused and transfused fetuses

OBJECTIVE

To assess the accuracy of middle cerebral artery peak systolic velocity (MCA-PSV) in prediction of severe fetal anemia resulting from Red Cell Alloimmunization (Anti-D) in un-transfused and transfused fetuses. In addition to comparing the accuracy of MCA-PSV and the estimation of the daily decline of fetal hemoglobin (Hb), to determine the appropriate time of subsequent transfusions.

STUDY DESIGN

This was a retrospective study of a series of 84 anaemic fetuses due to Red Cell alloimmunization. During each in-utero transfusion session, measurements of (1)MCA-PSV, (2)pre- and (3)post-transfusion Hb levels were recorded. Receiveroperating characteristics (ROC) curves, negative and positive predictive values of MCA-PSV in predicting severe fetal anemia were calculated. Regression analysis assesses the correlation between fetal HB and MCA-PSV, and between observed and expected fetal hemoglobin levels.

RESULTS

Eighty four anemic fetuses were included in the study and had an in-utero transfusion. The positive predictive value (PPV) of MCAPSV decreased sharply from 86.0 % at the first IUT, to 52.0 % and 52.1 % at the second and third IUTs respectively. According to the ROC curves, setting the cut-off at 1.70 MoM would provide the best performance of MCA-PSV with respect to the timing of the second and third IUT. Setting a higher threshold of 1.70 MoM for the 2nd and 3rd transfusions would increase the PPV from 52.0 % to 96.4 % at the second IUT, and from 52.1%-99.8 % at the third IUT.

CONCLUSION

In this study we suggest that a higher MCA-PSV (MoM 1.7 in compared to 1.5MOM) can accurately predict the recurrence of severe fetal anemia requiring serial IUTs. In transfused fetuses, MCAPSV accuracy to detect severe anemia decline slightly with increase number of IUT. In addition to that, the mean projected daily decrease in fetal hemoglobin has a similar accuracy to MCA-PSV in predicting moderate to severe fetal anemia.

Hemolytic disease of the fetus and newborn due to Rh(D) incompatibility: A preventable disease that still produces significant morbidity and mortality in children

In the mid-20th century, Hemolytic Disease of the Fetus and Newborn, caused by maternal alloimmunization to the Rh(D) blood group antigen expressed by fetal red blood cells (i.e., "Rh disease"), was a major cause of fetal and neonatal morbidity and mortality. However, with the regulatory approval, in 1968, of IgG anti-Rh(D) immunoprophylaxis to prevent maternal sensitization, the prospect of eradicating Rh disease was at hand. Indeed, the combination of antenatal and post-partum immunoprophylaxis is ~99% effective at preventing maternal sensitization to Rh(D). To investigate global compliance with this therapeutic intervention, we used an epidemiological approach to estimate the current annual number of pregnancies worldwide involving an Rh(D)-negative mother and an Rh(D)-positive fetus. The annual number of doses of anti-Rh(D) IgG required for successful immunoprophylaxis for these cases was then calculated and compared with an estimate of the annual number of doses of anti-Rh(D) produced and provided worldwide. Our results suggest that ~50% of the women around the world who require this type of immunoprophylaxis do not receive it, presumably due to a lack of awareness, availability, and/or affordability, thereby putting hundreds of thousands of fetuses and neonates at risk for Rh disease each year. The global failure to provide this generally acknowledged standard-of-care to prevent Rh disease, even 50 years after its availability, contributes to an enormous, continuing burden of fetal and neonatal disease and provides a critically important challenge to the international health care system.

Evaluation of maternal rhesus blood type as a risk factor in adverse pregnancy outcomes in Korea: a nationwide health insurance database study

OBJECTIVES

The current study aimed to investigate whether pregnancy outcomes are affected by maternal rhesus (Rh) status by comparing the primigravida pregnancy outcomes of Rh-negative women with those of Rh-positive women.

METHODS

The study data were collected from the Korea National Health Insurance Claims Database and the National Health Screening Program for Infants and Children. In total, 1,664,882 primigravida women who gave birth between January 1, 2007 and December 31, 2014, were enrolled in this study. As the risk and severity of sensitization response increases with each subsequent pregnancy, only primigravida women were enrolled. The patients were divided into 2 groups according to Rh status, and the pregnancy outcomes were compared.

RESULTS

In total, 1,661,320 women in the Rh-positive group and 3,290 in the Rh-negative group were assessed. With regard to adverse pregnancy outcomes, there was no statistically significant difference between the 2 groups in terms of the prevalence of preeclampsia, postpartum hemorrhage, abruptio placenta, placenta previa, and uterine artery embolization. A univariate analysis revealed that none of the adverse pregnancy outcomes were significantly correlated to Rh status (preeclampsia: odds ratio [OR], 1.00, 95% confidence interval [CI], 0.81-1.23; postpartum hemorrhage: OR, 1.10, 95% CI, 0.98-1.24; abruptio placenta: OR, 0.80, 95% CI, 0.46-1.37; and placenta previa: OR, 1.08, 95% CI, 0.78-1.42). The adjusted ORs of postpartum hemorrhage and preterm birth did not significantly differ.

CONCLUSION

Maternal Rh status is not associated with adverse outcomes in primigravida women.

Quality audit of the guidelines for the use of RhD immunoglobulin in obstetrics: Are we getting it right?

BACKGROUND

Administration of RhD immunoglobulin (Ig) is important for RhD negative women throughout pregnancy and postnatally to prevent alloimmunisation and haemolytic disease of the fetus and newborn in subsequent pregnancies.

AIMS

The aim of this audit was to understand compliance with the Australian guidelines on RhD Ig prophylaxis in pregnancy.

MATERIALS AND METHODS

This was a retrospective audit of RhD negative pregnant women in Victoria, Northern Territory, Australian Capital Territory and Tasmania at maternity services of level 2 or higher care, between July 2017 and June 2018. Medical records were reviewed to identify how many RhD negative women received care compliant with the guidelines covering antibody testing, consent, administration of RhD Ig, and feto-maternal haemorrhage (FMH) quantification.

RESULTS AND CONCLUSIONS

Analysis included 939 RhD negative women from 43 health services. Compliance with postnatal RhD Ig was high (98%); however, other practice was poor. Documented consent was obtained and recorded for 585 women (62%). Only 76% of eligible women received RhD Ig at the appropriate dose and time (28 and 34 weeks gestation). Similarly, management of potentially sensitising events was suboptimal with 78% receiving RhD Ig when recommended by guidelines. The results of our audit indicate a need for practice improvement across all aspects of care for women who need to receive RhD Ig. A major focus should be not just educating clinical staff, but also educating women to understand the importance of RhD Ig and the potential impact on subsequent pregnancies in order to improve guideline adherence and reduce risk.

Rural healthcare delivery: Navigating a complex ecosystem

Clinical Practice Guidelines (CPGs) provide evidence-based recommendations for Healthcare Providers (HCPs) to utilize when making patient care decisions. Rural providers face challenges in the provision of evidence-based care, including the use of guidelines. The aim of this article is to explore the complexities of providing healthcare in rural areas. This article will focus on a specific aspect of rural maternity care with well-established CPGs, the prevention of Rhesus D factor alloimmunization. An applied health research approach, interpretive description, utilized semistructured interviews with HCPs across the vast geographic region of northern British Columbia. The study found that HCPs are aware of guidelines but face various barriers during implementation. In order to implement guidelines within practice, rural HCPs adapt processes to overcome local barriers. These process adaptations need to be identified and shared across a large health authority with a complex geography and healthcare system to ensure quality of care.

Rhesus D factor (RhD) negative women's experiences with pregnancy: An interpretive description

BACKGROUND

The development of rh immune globulin (RhIG) for the prevention of Rhesus D (RhD) alloimmunization has significantly decreased the incidence of RhD alloimmunization. Despite long-standing prevention, the experiences of RhD negative women with pregnancy is absent in the literature.

AIM

The purpose of this study was to explore the experiences of RhD negative women with pregnancy.

METHODS

Utilizing an Interpretive Description approach, semi-structured interviews were conducted with RhD negative women about their pregnancies. This study took place within the geographic context of northern British Columbia (BC). The analysis involved a two-cycle approach to identify themes within the data.

FINDINGS

Sixteen RhD negative women that live in northern BC participated in this study. The analysis identified that RhD negative women are uninformed and want to be involved in the decision-making process regarding the prevention of RhD alloimmunization. The themes that emerged from the interview data were communication, information-seeking behaviour, out of sight out of mind, choice and trust, and patient advocacy.

DISCUSSION

The participants in this study described lacking information regarding the prevention of RhD alloimmunization. They sought information to overcome the gaps in knowledge and a desire to be involved in the decision-making process.

CONCLUSION

RhD negative women want information and to be involved in the decision-making process in the prevention of RhD alloimmunization. Working with RhD negative women to develop decision-aids and/or other educational tools to aid in the decision-making process are warranted.

Rhesus Isoimmunization: Late-onset Hemolytic Disease of the Newborn Without Jaundice

Rhesus (Rh) isoimmunization commonly presents with anemia and jaundice of varying intensity in the early postnatal period and is usually treated with phototherapy and exchange transfusion. Rarely, babies with mild or no symptoms at birth may present later with severe hemolytic anemia. This report describes a newborn infant with no postnatal jaundice who presented during the second week of life with severe anemia. These findings indicate the importance of regular follow-up and close monitoring of Rh-isoimmunized infants during the first two months of life for delayed onset anemia.

A Multicenter, Randomized, Open-Label Trial Comparing the Efficacy and Safety of Monoclonal Anti-Rh (D) Immunoglobulin with Polyclonal Anti-Rh (D) Immunoglobulin for the Prevention of Maternal Rh-Isoimmunization

Objectives

To compare the efficacy and safety of monoclonal anti-Rhesus (anti-D) immunoglobulin (IgG) with polyclonal anti-D IgG in the prevention of maternal Rh-isoimmunization.

Methods

This was a randomized, multicenter, open-label, comparative clinical trial conducted in the obstetric in-patient departments of nine tertiary care hospitals in India. 206 Rhesus (D)-negative women, not sensitized to Rh antigen, and delivering Rh positive babies, received postpartum intramuscular administration of monoclonal or polyclonal anti-D IgG. The main outcome measures were the proportion of subjects protected from Rh-isoimmunization, identified by a negative indirect Coombs test (ICT) result, at day 180 after anti-D IgG administration, and incidence of adverse events.

Results

105 subjects were randomized to the monoclonal group and 101 to the polyclonal group. 94 from the monoclonal group had a negative ICT result and none had a positive ICT result at day 180, whereas 87 from the polyclonal group had a negative ICT result and one had a positive ICT result; the rest (11 and 13 subjects respectively) were lost to follow-up. A total of 5 adverse events were reported (3 in the monoclonal group and 2 in the polyclonal group); only one of these was serious. All the adverse events were judged to be unrelated to the interventional drug. None of the subjects in the monoclonal group developed immunogenic reaction to the monoclonal anti-D.

Conclusion

The efficacy and safety of the monoclonal preparation of anti-D was comparable to the polyclonal preparation of anti-D when used in the prevention of maternal Rh-isoimmunization.Trial registration Clinical Trial Registration Number: CTRI/2015/09/006172.

High-throughput non-invasive prenatal testing for fetal rhesus D status in RhD-negative women not known to be sensitised to the RhD antigen: a systematic review and economic evaluation

BACKGROUND

High-throughput non-invasive prenatal testing (NIPT) for fetal rhesus (D antigen) (RhD) status could avoid unnecessary treatment with routine anti-D immunoglobulin for RhD-negative women carrying a RhD-negative fetus, although this may lead to an increased risk of RhD sensitisations.

OBJECTIVES

To systematically review the evidence on the diagnostic accuracy, clinical effectiveness and implementation of high-throughput NIPT and to develop a cost-effectiveness model.

METHODS

We searched MEDLINE and other databases, from inception to February 2016, for studies of high-throughput NIPT free-cell fetal deoxyribonucleic acid (DNA) tests of maternal plasma to determine fetal RhD status in RhD-negative pregnant women who were not known to be sensitised to the RhD antigen. Study quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) and A Cochrane Risk of Bias Assessment Tool: for Non-Randomised Studies of Interventions (ACROBAT-NRSI). Summary estimates of false-positive rates (FPRs) and false-negative rates (FNRs) were calculated using bivariate models. Clinical effectiveness evidence was used to conduct a simulation study. We developed a de novo probabilistic decision tree-based cohort model that considered four alternative ways in which the results of NIPT could guide the use of anti-D immunoglobulin antenatally and post partum. Sensitivity analyses (SAs) were conducted to address key uncertainties and model assumptions.

RESULTS

Eight studies were included in the diagnostic accuracy review, seven studies were included in the clinical effectiveness review and 12 studies were included in the review of implementation. Meta-analyses included women mostly at or post 11 weeks' gestation. The pooled FNR (women at risk of sensitisation) was 0.34% [95% confidence interval (CI) 0.15% to 0.76%] and the pooled FPR (women needlessly receiving anti-D) was 3.86% (95% CI 2.54% to 5.82%). SAs did not materially alter the overall results. Data on clinical outcomes, including sensitisation rates, were limited. Our simulation suggests that NIPT could substantially reduce unnecessary use of antenatal anti-D with only a small increase in the risk of sensitisation. All large implementation studies suggested that large-scale implementation of high-throughput NIPT was feasible. Seven cost-effectiveness studies were included in the review, which found that the potential for the use of NIPT to produce cost savings was dependent on the cost of the test. Our de novo model suggested that high-throughput NIPT is likely to be cost saving compared with the current practice of providing routine antenatal anti-D prophylaxis to all women who are RhD negative. The extent of the cost saving appeared to be sufficient to outweigh the small increase in sensitisations. However, the magnitude of the cost saving is highly sensitive to the cost of NIPT itself.

LIMITATIONS

There was very limited evidence relating to the clinical effectiveness of high-throughput NIPT, with no evidence on potential adverse effects. The generalisability of the findings to non-white women and multiple pregnancies is unclear.

CONCLUSIONS

High-throughput NIPT is sufficiently accurate to detect fetal RhD status in RhD-negative women from 11 weeks' gestation and would considerably reduce unnecessary treatment with routine anti-D immunoglobulin, potentially resulting in cost savings of between £485,000 and £671,000 per 100,000 pregnancies if the cost of implementing NIPT is in line with that reflected in this evaluation.

FUTURE WORK

Further research on the diagnostic accuracy of NIPT in non-white women is needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015029497.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Hyporegenerative anemia and other complications of rhesus hemolytic disease: to treat or not to treat is the question

Rhesus hemolytic disease of the newborn is rarely found after the implementation of anti-D immunoglobulin prophylaxis. However, it may lead to cholestasis, elevated liver transaminases, iron overload and late hyporegenerative anemia when it occurs. Etiology of this type of anemia is not defined yet and treatment is controversial. It is typically recognized after two weeks of life which is characterized by low hemoglobin and reticulocyte count. We have reported a case of a neonate with Rh hemolytic disease with late hyporegenerative anemia that was noted at day 18 of life. We treated this anemia by erythropoietin (EPO) 250 U/kg three times per week. Two weeks after initiation of erythropoietin treatment, a stable hemoglobin was noted along with an increased reticulocyte count. The patient required one further blood transfusion in the third week of therapy. Other associated findings were self-limited. A year of follow-up showed an appropriate development for age.

Single-stranded DNA aptamer targeting and neutralization of anti-D alloantibody: a potential therapeutic strategy for haemolytic diseases caused by Rhesus alloantibody

BACKGROUND

Rhesus (Rh) D antigen is the most important antigen in the Rh blood group system because of its strong immunogenicity. When RhD-negative individuals are exposed to RhD-positive blood, they may produce anti-D alloantibody, potentially resulting in delayed haemolytic transfusion reactions and Rh haemolytic disease of the foetus and newborn, which are difficult to treat. Inhibition of the binding of anti-D antibody with RhD antigens on the surface of red blood cells may effectively prevent immune haemolytic diseases.

MATERIALS AND METHODS

In this study, single-stranded (ss) DNA aptamers, specifically binding to anti-D antibodies, were selected via systematic evolution of ligands by exponential enrichment (SELEX) technology. After 14 rounds of selection, the purified ssDNA was sequenced using a Personal Genome Machine system. Haemagglutination inhibition assays were performed to screen aptamers for biological activity in terms of blocking antigen-antibody reactions: the affinity and specificity of the aptamers were also determined.

RESULTS

In addition to high specificity, the aptamers which were selected showed high affinity for anti-D antibodies with dissociation constant (K_d) values ranging from 51.46±14.90 to 543.30±92.59 nM. By the combined use of specific ssDNA aptamer 7 and auxiliary ssDNA aptamer 2, anti-D could be effectively neutralised at low concentrations of the aptamers.

DISCUSSION

Our results demonstrate that ssDNA aptamers may be a novel, promising strategy for the treatment of delayed haemolytic transfusion reactions and Rh haemolytic disease of the foetus and newborn.