Practice Bulletin No. 181: Prevention of Rh D Alloimmunization

Estimating the cost of Rh testing and prophylaxis in early pregnancy: A time-driven activity-based costing study

OBJECTIVE

To estimate the cost of Rhesus (Rh) testing and prophylaxis for first-trimester vaginal bleeding in the ambulatory setting.

STUDY DESIGN

We used time-driven, activity-based costing to analyze tasks associated with Rh testing and prophylaxis of first-trimester vaginal bleeding at one hospital-based outpatient and two independent reproductive health clinics. At each site, we observed 10 patients undergoing Rh-typing and two patients undergoing Rh prophylaxis. We computed the costs of blood Rh-typing by both fingerstick and phlebotomy, cost of locating previous blood type in the electronic health record (available for 69.8% of hospital-based patients), and costs associated with Rh immune globulin prophylaxis. All costs are reported in 2021 US dollars.

RESULTS

The hospital-based clinic reviewed the electronic health record to confirm Rh-status (cost, $26.18 per patient) and performed a phlebotomy, at $47.11 per patient, if none was recorded. The independent clinics typed blood by fingerstick, at a per-patient cost of $4.07. Rh-immune globulin administration costs, including the medication, were similar across facilities, at a mean of $145.66 per patient. Projected yearly costs for testing and prophylaxis were $55,831 for the hospital-based clinic, which was the lowest-volume site, $47,941 for Clinic A, which saw 150 patients/month, and $185,654 for Clinic B, which saw 600 patients/month.

CONCLUSIONS

Rh testing and prophylaxis for first-trimester vaginal bleeding generates considerable costs for outpatient facilities, even for Rh-positive patients with a prior blood type on record.

IMPLICATIONS

Rh testing and prophylaxis for first-trimester bleeding generate considerable costs even for Rh-positive patients and those with a previously known blood type. These findings highlight the need to reconsider this practice, which is no longer supported by evidence and already safely waived in multiple medical settings in the United States and around the world.

Normal Pregnancy Care and Physiology and Select Pregnancy Complications: A Flipped Classroom Case for the OB/GYN Clerkship

Introduction

This module teaches core knowledge and skills for undergraduate medical education in reproductive health, providing instruction in the management of normal and abnormal pregnancy and labor utilizing interactive small-group flipped classroom methods and case-based instruction.

Methods

Advance preparation materials were provided before the education session. The 2-hour session was facilitated by clinical educators using a faculty guide. Using voluntary surveys, we collected data to measure satisfaction among obstetrics and gynecology clerkship students and facilitators following each education session.

Results

Capturing six clerkships spanning 9 months, 116 students participated, and 64 students completed the satisfaction survey, with 97% agreeing that the session was helpful in applying knowledge and principles to common clinical scenarios. Most students (96%) self-reported that they achieved the session's learning objectives utilizing prework and interactive small-group teaching. Nine clinical instructors completed the survey; all agreed the provided materials allowed them to facilitate active learning, and the majority (89%) agreed they spent less time preparing to teach this curriculum compared to traditional didactics.

Discussion

This interactive flipped classroom session meets clerkship learning objectives related to the management of pregnancy and labor using standardized materials. The curriculum reduced preparation time for clinical educators as well.

Guide to Rho(D) Immune Globulin in Women With Molecularly Defined Asian-type DEL (c.1227G>A)

Rh hemolytic disease of the fetus and newborn is a potential risk for D-negative mothers who produce anti-D during pregnancy, which can lead to morbidity and mortality in subsequent pregnancies. To prevent this hemolytic disease, Rho(D) immune globulin (RhIG) is generally administered to D-negative mothers without anti-D at 28 weeks of gestation and shortly after delivery. However, current guidelines suggest that pregnant mothers with molecularly defined weak D types 1, 2, 3, 4.0, and 4.1 do not need RhIG as they are unlikely to produce alloanti-D when exposed to fetuses with D-positive red cells. This issue and the necessity of RHD genotyping have been extensively discussed in Western countries, where these variants are relatively common. Recent evidence indicates that women with Asian-type DEL (c.1227G>A) also do not form alloanti-D when exposed to D-positive red cells. We report that mothers with molecularly defined Asian-type DEL, similar to those with weak D types 1, 2, 3, 4.0, and 4.1, do not require RhIG before and after delivery. Collectively, this review could pave the way for the revision of international guidelines to include the selective use of RhIG based on specific genotypes, particularly in women with the Asian-type DEL.

[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.

Is Feto-Maternal Transfusion after Cesarean Delivery Different in Singleton and Twin Pregnancy?

Background: The aim of the study was to investigate if feto-maternal transfusion was related to the size of the fetal-maternal interface, and, therefore, was larger in twin pregnancy in comparison with singleton pregnancy. Methods: Blood samples from women with singleton (n = 11), and monochorionic (n = 11) and dichorionic (n = 13) twin gestations were tested. Flow cytometry tests with hemoglobin F, glycophorin A, and hemoglobin F and carbonic anhydrase simultaneous staining were used to detect fetal red blood cells and maternal F cells. Results: In all cases, the volume of feto-maternal transfusion was estimated to be low. The highest rate of fetal red blood cells in the maternal circulation was observed in the blood of women with dichorionic twin gestations both before and after delivery. An increase in fetal red blood cells was observed after cesarean section in singletons and twins. The median rate of maternal F cells was 2.23% in singleton, 2.1% in monochorionic and 3.95% in dichorionic pregnancy. Conclusions: Feto-maternal transfusion during pregnancy may be related to the multiplicity and chorionicity of pregnancy.

Economic analysis of foregoing Rh immunoglobulin for bleeding in pregnancy <12 weeks gestation

OBJECTIVES

To perform cost analyses of foregoing RhD blood type testing and administration of Rh immunoglobulin (RhIg) for bleeding in pregnancy at <12 weeks gestation in the United States.

STUDY DESIGN

We created a decision-analytic model comparing the current standard treatment pathway for patients who have threatened, spontaneous, or induced abortion in the United States, with a new pathway foregoing RhD testing and administration of RhIg for those who are RhD-negative at <12 weeks gestation, assuming that the risk of sensitization is 0%. We derived population and cost estimates from the current literature and calculated the number needed to treat (NNT) and number needed to screen to avoid one case of fatal hemolytic disease of the fetus and newborn. We performed sensitivity analyses assuming Rh-sensitization risks of 1.5% and 3% and varying the subsequent pregnancy rates from 44% to 100%.

RESULTS

The annual savings to health care payers in the United States of foregoing RhD testing and RhIg administration with bleeding events at <12 weeks are $5.5 million/100,000 total pregnancies, assuming the sensitization risk is 0%. In sensitivity analyses with a sensitization risk of 1.5% and subsequent pregnancy rate of 84.3% foregoing Rh testing and RhIg administration would save $2.8 million/100,000 pregnancies, with a NNT of 7322 and a number needed to screen of 48,816. At a 3% sensitization rate, the current standard treatment pathway is most economical.

CONCLUSIONS

There is an opportunity to save as much as $5.5 million/100,000 pregnancies by withholding RhIg in specific situations and conserving it for use later in pregnancy.

IMPLICATIONS

Cost analyses support foregoing RhD blood type screening and RhIg administration at <12 weeks gestation if the sensitization rate is <3%. By deimplementing this low-value care, payers in the United States can save as much as $5.5 million/100,000 pregnancies and conserve RhIg for use later in pregnancy.

HPLC and flow cytometry combined approach for HbF analysis in fetomaternal haemorrhage evaluation

Introduction

Recently, a flow cytometric (FC) based test has been developed for detection of circulating fetal cells to replace the less accurate and reproducible Kleihauer-Betke test.FC test is easier to perform, it can distinguish the origin of fetal cells, but it is expensive and available in highly specialized laboratories. We evaluated the introduction of high-performance liquid chromatography (HPLC) approach as initial screening to identify patients who need an additional FC test to better discriminate the nature of haemoglobin-F (HbF) positive cells.

Methods

Blood samples from 130 pregnant women suspected to have fetomaternal haemorrhage were analysed with HPLC and FC methods. The cut-off for HbF HPLC concentration was calculated. Statistical analyses for the evaluation of HPLC as a screening method were performed. The positivity cut-off of HbF to be used as decision-making value to continue the investigation was calculated.

Results

An excellent agreement (R2 > 0.90) was observed between the percentage of HbF obtained by HPLC and the percentage of fetal cells detected by FC. Results obtained from each assay were compared to define the HPLC threshold below which it is not necessary to continue the investigations, confirming the maternal nature of the HbF positive cells detected. Our study demonstrated that a cut-off of 1.0 % HbF obtained by HPLC was associated with the lowest rate of false negative results in our patient cohort.

Conclusions

This study provides a new FMH investigation approach that possibly leads to a reduction in times and costs of the analysis.

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.

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.

First-trimester Procedural Abortion

First-trimester abortion is a common and safe procedure. A focused history and physical examination are essential for providing this care. Laboratory assessment can include Rh typing, hemoglobin, and cervicitis testing as indicated by a patient's risk factors. Procedural abortion in the first trimester includes cervical dilation with or without cervical preparation, and uterine evacuation utilizing a manual vacuum aspirator or electric vacuum aspirator. Complications occur rarely and are often easily managed at the time of diagnosis.

Alloimmune hemolytic disease of the fetus and newborn: genetics, structure, and function of the commonly involved erythrocyte antigens

Hemolytic disease of the fetus and newborn (HDFN) can occur when a pregnant woman has antibody directed against an erythrocyte surface antigen expressed by her fetus. This alloimmune disorder is restricted to situations where transplacental transfer of maternal antibody to the fetus occurs, and binds to fetal erythrocytes, and significantly shortens the red cell lifespan. The pathogenesis of HDFN involves maternal sensitization to erythrocyte "non-self" antigens (those she does not express). Exposure of a woman to a non-self-erythrocyte antigen principally occurs through either a blood transfusion or a pregnancy where paternally derived erythrocyte antigens, expressed by her fetus, enter her circulation, and are immunologically recognized as foreign. This review focuses on the genetics, structure, and function of the erythrocyte antigens that are most frequently involved in the pathogenesis of alloimmune HDFN. By providing this information we aim to convey useful insights to clinicians caring for patients with this condition.

Whole Blood Administration for Obstetric-Related Hemorrhage During Prehospital Transport

BACKGROUND

Whole blood transfusion has been used for resuscitation in trauma patients; however, case reports of whole blood transfusion for obstetric-related hemorrhage are limited. Whole blood transfusion typically is accomplished with low titer O-positive whole blood, and, despite success in trauma, use in persons with childbearing potential is of concern due to risk of alloimmunization.

CASE

We present a case series of patients who received low titer O-positive whole blood for obstetric hemorrhage. One patient was Rh-negative and received immune globulin treatment after whole blood transfusion. All patients survived to hospital discharge. None experienced transfusion-related complications.

CONCLUSION

Whole blood can be successfully administered both in and out of the hospital setting, even for obstetric hemorrhage. The benefits of easily administered balanced resuscitation, limited donor exposure, and improved patient outcomes likely outweigh potential alloimmunization, especially in resource-limited settings. Addressing concerns of alloimmunization cannot be accomplished without more research, and we encourage others to investigate using whole blood in this population.

Induced Abortion and the Risk of Rh Sensitization

Importance

While population-level data suggest Rh immunoglobulin is unnecessary before 12 weeks' gestation, clinical evidence is limited. Thus, guidelines vary, creating confusion surrounding risks and benefits of Rh testing and treatment. As abortion care in traditional clinical settings becomes harder to access, many people are choosing to self-manage and need to know if ancillary blood type testing is necessary.

Objective

To determine how frequently maternal exposure to fetal red blood cells (fRBCs) exceeds the most conservative published threshold for Rh sensitization in induced first-trimester abortion.

Design, Setting, and Participants

Multicenter, observational, prospective cohort study using high-throughput flow cytometry to detect circulating fRBCs in paired maternal blood samples before and after induced first-trimester abortion (medication or procedural). Individuals undergoing induced first-trimester abortion before 12 weeks 0 days' gestation were included. Paired blood samples were available from 506 participants who underwent either medical (n = 319 [63.0%]) or procedural (n = 187 [37.0%]) abortion.

Exposure

Induced first-trimester abortion.

Main Outcomes and Measures

The primary outcome was the proportion of participants with fRBC counts above the sensitization threshold (125 fRBCs/5 million total RBCs) after induced first-trimester abortion.

Results

Among the 506 participants, the mean (SD) age was 27.4 (5.5) years, 313 (61.9%) were Black, and 123 (24.3%) were White. Three of the 506 participants had elevated fRBC counts at baseline; 1 of these patients had an elevated fRBC count following the abortion (0.2% [95% CI, 0%-0.93%]). No other participants had elevated fRBC counts above the sensitization threshold after induced first-trimester abortion. The median change from baseline was 0 fRBCs, with upper 95th and 99th percentiles of 24 and 35.6 fRBCs, respectively. Although there was a strong association between the preabortion and postabortion fRBC counts, no other baseline characteristic was significantly associated with postabortion fRBC count.

Conclusions and Relevance

Induced first-trimester abortion is not a risk factor for Rh sensitization, indicating that Rh testing and treatment are unnecessary before 12 weeks' gestation. This evidence may be used to inform international guidelines for Rh immunoglobulin administration following first-trimester induced abortion.

Vaginal Bleeding Before 20 Weeks Gestation

Conditions that often present with vaginal bleeding before 20 weeks are common and can cause morbidity and mortality. Clinically stable patients can choose their management options. Clinically unstable patients require urgent procedural management: uterine aspiration, dilation and evacuation, or surgical removal of an ectopic pregnancy. Septic abortion requires prompt procedural management, intravenous antibiotics, and intravenous fluids. Available data on prognosis with expectant management of pre-viable rupture of membranes in the United States are poor for mothers and fetuses.

Validation of a non-invasive prenatal test for fetal RhD, C, c, E, K and Fya antigens

We developed and validated a next generation sequencing-(NGS) based NIPT assay using quantitative counting template (QCT) technology to detect RhD, C, c, E, K (Kell), and Fya (Duffy) fetal antigen genotypes from maternal blood samples in the ethnically diverse U.S. population. Quantitative counting template (QCT) technology is utilized to enable quantification and detection of paternally derived fetal antigen alleles in cell-free DNA with high sensitivity and specificity. In an analytical validation, fetal antigen status was determined for 1061 preclinical samples with a sensitivity of 100% (95% CI 99-100%) and specificity of 100% (95% CI 99-100%). Independent analysis of two duplicate plasma samples was conducted for 1683 clinical samples, demonstrating precision of 99.9%. Importantly, in clinical practice the no-results rate was 0% for 711 RhD-negative non-alloimmunized pregnant people and 0.1% for 769 alloimmunized pregnancies. In a clinical validation, NIPT results were 100% concordant with corresponding neonatal antigen genotype/serology for 23 RhD-negative pregnant individuals and 93 antigen evaluations in 30 alloimmunized pregnancies. Overall, this NGS-based fetal antigen NIPT assay had high performance that was comparable to invasive diagnostic assays in a validation study of a diverse U.S. population as early as 10 weeks of gestation, without the need for a sample from the biological partner. These results suggest that NGS-based fetal antigen NIPT may identify more fetuses at risk for hemolytic disease than current clinical practice, which relies on paternal genotyping and invasive diagnostics and therefore is limited by adherence rates and incorrect results due to non-paternity. Clinical adoption of NIPT for the detection of fetal antigens for both alloimmunized and RhD-negative non-alloimmunized pregnant individuals may streamline care and reduce unnecessary treatment, monitoring, and patient anxiety.

Reduced Compared With Traditional Schedules for Routine Antenatal Visits: A Systematic Review

OBJECTIVE

To assess differences in maternal and child outcomes in studies comparing reduced routine antenatal visit schedules with traditional schedules.

DATA SOURCES

A search was conducted of PubMed, Cochrane databases, EMBASE, CINAHL, and ClinicalTrials.gov through February 12, 2022, searching for antenatal (prenatal) care, pregnancy, obstetrics, telemedicine, remote care, smartphones, telemonitoring, and related terms, as well as primary study designs. The search was restricted to high-income countries.

METHODS OF STUDY SELECTION

Double independent screening was done in Abstrackr for studies comparing televisits and in-person routine antenatal care visits for maternal, child, health care utilization, and harm outcomes. Data were extracted into SRDRplus with review by a second researcher.

TABULATION, INTEGRATION, AND RESULTS

Five randomized controlled trials and five nonrandomized comparative studies compared reduced routine antenatal visit schedules with traditional schedules. Studies did not find differences between schedules in gestational age at birth, likelihood of being small for gestational age, likelihood of a low Apgar score, likelihood of neonatal intensive care unit admission, maternal anxiety, likelihood of preterm birth, and likelihood of low birth weight. There was insufficient evidence for numerous prioritized outcomes of interest, including completion of the American College of Obstetricians and Gynecologists-recommended services and patient experience measures.

CONCLUSION

The evidence base is limited and heterogeneous and allowed few specific conclusions. Reported outcomes included, for the most part, standard birth outcomes that do not have strong plausible biological connection to structural aspects of antenatal care. The evidence did not find negative effects of reduced routine antenatal visit schedules, which may support implementation of fewer routine antenatal visits. However, to enhance confidence in this conclusion, future research is needed, particularly research that includes outcomes of most importance and relevance to changing antenatal care visits.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021272287.

First-Trimester Pregnancy: Considerations for Wilderness and Remote Travel

Women increasingly participate in outdoor activities in wilderness and remote environments. We performed a literature review to address diagnostic and therapeutic considerations during first-trimester pregnancy for remote multiday travel. Pretrip planning for pregnant patients traveling outside access to advanced medical care should include performing a transvaginal ultrasound to confirm pregnancy location and checking D rhesus status. We discuss the risk of potential travel-related infections and recommended vaccinations prior to departure based on destination. Immediate evacuation to definitive medical care is required for patients with a pregnancy of unknown location and vaginal bleeding. We propose algorithms for determining the need for evacuation and present therapeutic options for nausea and vomiting, urinary tract infections, and candidiasis in the field.

Live birth prevalence of hemolytic disease of the fetus and newborn in the United States from 1996 to 2010

BACKGROUND

Hemolytic disease of the fetus and newborn (HDFN) is mediated by maternal alloantibodies, a consequence of immune sensitization during pregnancy with maternal-fetal incompatibility with ABO, Rhesus factor (Rh), and/or other red blood cell antigens. RhD, Kell, and other non-ABO alloantibodies are the primary cause of moderate to severe HDFN, whereas ABO HDFN is typically mild. HDFN live birth prevalence owing to Rh alloimmunization among newborns in the United States was last estimated to be 106 per 100,000 births in 1986. HDFN live birth prevalence owing to all alloantibodies was estimated to be 817 to 840 per 100,000 in Europe. There is a need for updated prevalence estimates in the United States and a better understanding of disease demographics, severity, and treatments.

OBJECTIVE

This study aimed to estimate the live birth prevalence of HDFN and the proportion of severe cases of HDFN in the United States, to describe the associated risk factors, and to compare the clinical outcomes and treatments among healthy newborns, newborns with HDFN, and newborns who are sick without HDFN using a nationally representative hospital discharge database.

STUDY DESIGN

In this retrospective, observational cohort study, we used data from the 1996 to 2010 National Hospital Discharge Survey to identify live births, defined by inpatient visits with the newborn flag, with and without a diagnosis of HDFN across 200 to 500 sampled hospitals (≥6 beds) per year. Patient and hospital characteristics, alloimmunization status, disease severity, treatment, and clinical outcomes were evaluated. Frequencies and weighted percentages were calculated for all variables. Logistic regression was used to compare the characteristics between newborns with HDFN and other newborns using odds ratios.

RESULTS

Of 480,245 live births identified, 9810 HDFN cases were recorded. When weighted to the United States population, this corresponded to a live birth prevalence of 1695 per 100,000 live births. Compared with other newborns, newborns with HDFN were more likely to be female, Black, living in the South (vs the Midwest or West), and treated at larger (>100 beds) and government-owned hospitals. ABO and Rh alloimmunization accounted for 78.1% and 4.3% of newborns with HDFN, respectively, whereas HDFN caused by other antigens, such as Kell and Duffy, accounted for 17.6% of the cases. Among newborns with HDFN, 22% received phototherapy, 1% received simple transfusions, and 0.5% received exchange transfusions or intravenous immunoglobulin. Newborns affected by HDFN caused by Rh alloimmunization were more likely to require medical interventions, including simple or exchange transfusions, and more likely to be delivered by cesarean delivery. Overall, HDFN was associated with a longer hospital length of stay in the neonatal intensive care unit when compared with healthy and other sick newborns, a higher rate of cesarean delivery, and a higher rate of nonroutine discharge than healthy newborns.

CONCLUSION

Overall, the live birth prevalence of HDFN was higher than those previously reported, whereas Rh-induced HDFN live birth prevalence was similar to those previously reported. HDFN live birth prevalence owing to Rh alloimmunization decreased over time, likely because of continued Rh immune globulin prophylaxis. Treatment patterns for newborns with HDFN and the comparative clinical outcomes when compared with healthy newborns confirm the continued clinical needs of this population.

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.

Rh Immune Globulin After the Transfusion of RhD-Positive Blood in a Patient with a Partial D Antigen

BACKGROUND

Patients with a serologic weak D phenotype may demonstrate variable RhD expression. We present a case in which clinical management would have been simplified if RHD genotyping had been performed previously.

CASE

A 33-year-old patient, G11P4155, presented with an incomplete miscarriage and was transfused RhD-positive packed red blood cells after typing RhD-positive. The patient had been historically typed RhD-negative by a different testing methodology. Indirect antiglobulin testing was performed, which revealed a serologic weak D phenotype. The patient was given 9,600 micrograms of Rh immune globulin. Molecular testing revealed a partial D antigen, which was originally thought to be at risk for alloimmunization; however, this has since been disproven.

CONCLUSION

Although not yet universal practice, prenatal RHD genotyping for partial D antigen could have prevented the characterization of this patient as RhD-positive at the time of transfusion.

Fetomaternal hemorrhage assessment in Rh-negative patients undergoing dilation and evacuation between 20 and 24 weeks' gestational age: A retrospective cohort study

OBJECTIVE

To estimate the rate of requiring more than one 300-mcg Rh D immune globulin dose for fetomaternal hemorrhage (FMH) at the time of second-trimester dilation and evacuation (D + E).

STUDY DESIGN

We performed a retrospective cohort analysis of patients at greater than 20 weeks' gestation who underwent D + E, had Rh D-negative blood type, and received FMH quantification testing.

RESULTS

Of 25 eligible patients, 24 had negative quantification of FMH; one had positive quantification that did not meet the clinical threshold for additional dosing.

CONCLUSIONS

The absolute risk of requiring additional Rh D immune globulin after D+E for pregnancies greater than 20 weeks' gestation was 0%.

Michigan Plan for Appropriate Tailored Healthcare in Pregnancy Prenatal Care Recommendations: A Practical Guide for Maternity Care Clinicians

Prenatal care is an important preventive service designed to improve the health of pregnant patients and their infants. Prenatal care delivery recommendations have remained unchanged since 1930, when the 12-14 in-person visit schedule was first established to detect preeclampsia. In 2020, the American College of Obstetricians and Gynecologists, in collaboration with the University of Michigan, convened a panel of maternity care experts to determine new prenatal care delivery recommendations. The panel recognized the need to include emerging evidence and experience, including significant changes in prenatal care delivery during the COVID-19 pandemic, pre-existing knowledge of the importance of individualized care plans, the promise of telemedicine, and the significant influence of social and structural determinants of health (SSDoH) on pregnancy outcomes. Recommendations were derived using the RAND-UCLA appropriateness method, a rigorous e-Delphi method, and are designed to extend beyond the acute public health crisis. The resulting Michigan Plan for Appropriate Tailored Healthcare in pregnancy (MiPATH) includes recommendations for key aspects of prenatal care delivery: (1) the recommended number of prenatal visits, (2) the frequency of prenatal visits, (3) the role of monitoring routine pregnancy parameters (blood pressure, fetal heart tones, weight, and fundal height), (4) integration of telemedicine into routine care, and (5) inclusion of (SSDoH). Resulting recommendations demonstrate a new approach to prenatal care delivery that incorporates medical, SSDoH, and patient preferences, to develop individualized prenatal care delivery plans. The purpose of this document is to outline the new MiPATH recommendations and to provide practical guidance on implementing them in routine practice.

Following targeted routine antenatal anti-D prophylaxis, almost half of the pregnant women had undetectable anti-D prophylaxis at delivery

INTRODUCTION

In September 2016, a nationwide targeted routine antenatal anti-D prophylaxis program was implemented in Norway. The prophylaxis (anti-D immunoglobulin) aims to cover the whole third trimester and is administered in gestational week 28 to RhD-negative women who carry RhD-positive fetuses. However, in many women, antibody screening at delivery does not detect anti-D immunoglobulin. The goal of this study was to investigate the presumable role of dose and timing of antenatal anti-D immunoglobulin administration in non-detectable prophylaxis at the time of delivery.

MATERIAL AND METHODS

In this retrospective observational study, RhD-negative pregnant women who gave birth at Oslo University Hospital and Akershus University Hospital between January 2017 and December 2019 were analyzed. Women who received antenatal anti-D immunoglobulin (1500 IU at Oslo University Hospital and 1250 IU at Akershus University Hospital) when fetal RHD genotyping at gestational week 24 predicted an RhD-positive fetus were included if an antibody screen at delivery was available. Data from the blood bank, maternity information systems, and electronic patient records were used.

RESULTS

Analysis of the 984 RhD-negative women at the two hospitals revealed that 45.4% had non-detectable anti-D at delivery. A significant difference between the two hospitals was observed: 40.5% at Oslo University Hospital (n = 509) and 50.7% at Akershus University Hospital (n = 475) (p = 0.001). The proportion with non-detectable anti-D increased to 56.0 and 75.3%, respectively (p = 0.008) in the group of women who gave birth 12 weeks after routine antenatal anti-D prophylaxis. Significantly fewer women had detectable anti-D at delivery when the lower anti-D immunoglobulin dose (1250 IU) was administered antenatally. Multiple logistic regression indicated that the time interval between routine antenatal anti-D prophylaxis and delivery, in addition to anti-D dose, were significantly associated with detectable anti-D at delivery (p < 0.001).

CONCLUSIONS

We do not know which RhD-negative pregnant women, despite antenatal anti-D prophylaxis, are at risk of RhD alloimmunization, when antibody screening is negative at delivery. Administration of antenatal prophylaxis should probably be moved closer to delivery, since the risk of fetomaternal hemorrhage is higher during the last weeks of the third trimester.

Missed RHIG administration to postpartum patients in two health systems: an unrecognized patient safety risk

BACKGROUND

Maternal-fetal Rh-alloimmunization is a rare but potentially fatal event, most often caused by maternal exposure to D-antigen-presenting Rh-positive erythrocytes at the time of delivery. Prophylaxis with anti-D immune globulin is highly effective with a low side-effect profile and results in a dramatically decreased risk of alloimmunization. Postpartum anti-D immune globulin prophylaxis is recommended by national societies to reduce Rh-alloimmunization. We hypothesized that a small number of postpartum patients do not receive prophylaxis as indicated.  

OBJECTIVE

We investigated patients in 2 separate health systems that did not receive indicated prophylaxis and devised a suite of Electronic Health Record interventions to prevent future errors.

STUDY DESIGN

We reviewed charts retrospectively from Electronic Health Record data of 2 urban academic health systems, the MetroHealth System and Oregon Health & Science University. We identified all Rh-negative postpartum patients and their infants delivering from 2014 to 2019. The primary outcome was the proportion of postpartum patients not receiving indicated anti-D immune globulin prophylaxis. Once cases of missed anti-D immune globulin prophylaxis were identified, we reviewed individual charts to determine the relevant clinical circumstances and potential causes for error.

RESULTS

Of 29,801 deliveries over 5 years (15,444 at MetroHealth System and 14,357 at Oregon Health & Science University), there were 3087 Rh-negative postpartum patients, of whom 7 were alloimmunized and ineligible for prophylaxis. Anti-D immune globulin was indicated for 2162 (70.0%) women as they delivered an Rh-positive infant. A total of 37 indicated patients did not receive postpartum anti-D immune globulin. Twenty patients were offered prophylaxis and declined. We missed a total of 17 opportunities, thus our institutions appropriately offered indicated anti-D prophylaxis to 99.2% of patients over a period of 5 years. Of the 17 true misses, anti-D immune globulin was ordered for some patients, whereas others did not have an anti-D immune globulin order placed. A toolkit in the Electronic Health Record consisting of decision-support hard stops, automated documentation, and longitudinal reporting was implemented at the MetroHealth System in the year after its inception. The Toolkit identified and helped prevent 4 potential misses, resulting in a 100% anti-D prophylaxis rate at the MetroHealth System.

CONCLUSION

Given the serious nature of Rh-alloimmunization, we believe missed prophylaxis should be a never event. Through examination of our current processes, we identified areas of improvement and developed a Postpartum Anti-D Immune Globulin Prophylaxis Electronic Health Record Toolkit, which showed improvement in administration rates. Such a toolkit has the potential to identify patients appropriately and avoid missed anti-D immune globulin prophylaxis events.

Early Hyporegenerative Anemia Complicating Hemolytic Disease of the Newborn Secondary to Rhesus Alloimmunization

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, hyperbilirubinemia, kernicterus, iron overload, and hyporegenerative anemia. Hyporegenerative anemia is characterized by low hemoglobin and reticulocyte count. It is typically recognized two to six weeks after birth. The etiology of this type of anemia is not identified yet, and treatment is controversial. We report a case of a neonate with rhesus hemolytic disease of the newborn with early hyporegenerative anemia that was noted on day seven of life. The available literature has described a similar age of onset, but after two weeks of life and not as early as on day seven of life as in our case. We treated this type of anemia with the standard of care management that includes phototherapy, intravenous immunoglobulin, and blood transfusions.

Leveraging American College of Obstetricians and Gynecologists Guidelines for Point-of-Care Decision Support in Obstetrics

BACKGROUND

The American College of Obstetricians and Gynecologists (ACOG) provides numerous narrative documents containing formal recommendations and additional narrative guidance within the text. These guidelines are not intended to provide a complete "care pathway" for patient management, but these elements of guidance can be useful for clinical decision support (CDS) in obstetrical and gynecologic care and could be exposed within electronic health records (EHRs). Unfortunately, narrative guidelines do not easily translate into computable CDS guidance.

OBJECTIVE

This study aimed to describe a method of translating ACOG clinical guidance into clear, implementable items associated with specific obstetrical problems for integration into the EHR.

METHODS

To translate ACOG clinical guidance in Obstetrics into implementable CDS, we followed a set of steps including selection of documents, establishing a problem list, extraction and classification of recommendations, and assigning tasks to those recommendations.

RESULTS

Our search through ACOG clinical guidelines produced over 500 unique documents. After exclusions, and counting only sources relevant to obstetrics, we used 245 documents: 38 practice bulletins, 113 committee opinions, 16 endorsed publications, 1 practice advisory, 2 task force and work group reports, 2 patient education, 2 obstetric care consensus, 60 frequently asked questions (FAQ), 1 women's health care guidelines, 1 Prolog series, and 9 others (non-ACOG). Recommendations were classified as actionable (n = 576), informational (n = 493), for in-house summary (n = 124), education/counseling (n = 170), policy/advocacy (n = 33), perioperative care (n = 4), delivery recommendations (n = 50), peripartum care (n = 13), and non-ACOG (n = 25).

CONCLUSION

We described a methodology of translating ACOG narrative into a semi-structured format that can be more easily applied as CDS in the EHR. We believe this work can contribute to developing a library of information within ACOG that can be continually updated and disseminated to EHR systems for the most optimal decision support. We will continue documenting our process in developing executable code for decision support.

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.

Fetal-Maternal Hemorrhage in First-Trimester Intrauterine Hematoma

OBJECTIVE

The objective of this study was to compare the frequency and percentage of fetal hemoglobin (HbF%) by flow cytometry of (1) first-trimester asymptomatic patients with intrauterine hematoma (IUH), (2) first-trimester pregnant patients with vaginal bleeding (VB), and (3) first-trimester asymptomatic pregnant women without hematoma.

METHODS

Prospective study involving pregnant women in the first trimester of pregnancy. Patients with ultrasound findings of asymptomatic hematoma and with VB were paired with asymptomatic pregnant women of same gestational age without hematoma (control group [CG]). Maternal blood HbF% was evaluated by flow cytometry. The groups were compared in terms of circulating fetal hemoglobin and HbF%.

RESULTS

Sixty-six patients were selected, 22 with hematoma, 17 with bleeding, and 27 in the CG. Fetal hemoglobin was detected in 15 patients with hematoma (68.2%) and 13 with bleeding (76.5%) and in 20 of the control (74.1%) (p = 0.830). The mean HbF% of each group was 0.054, 0.012, and 0.042 for hematoma, bleeding, and control, respectively, and differences were not significant (p = 0.141). There was a moderate negative correlation between the volume of hematoma and HbF% (rSpearman = -0.527; p = 0.012).

CONCLUSIONS

The fetal-maternal hemorrhage expressed by Hbf% in first-trimester pregnancies did not seem to differ between patients with and without ultrasound findings of IUH.

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

The introduction of anti‐Rh(D) immunoglobulin more than 50 years ago has resulted in only a 50% decrease in Rhesus disease globally owing to a low uptake of this prophylactic approach. The International Federation of Gynecology and Obstetrics, International Confederation of Midwives, and Worldwide Initiative for Rhesus Disease Eradication have reviewed current evidence regarding the utility of anti‐Rh(D) immunoglobulin. Taking into account the effectiveness anti‐Rh(D), the new guidelines propose adjusting the dose for different indications and prioritizing its administration by indication.

These FIGO/ICM guidelines review the evidence regarding the usefulness of anti‐Rh(D) immunoglobulin, prioritizing its administration by indication.

Implementation of a Standardized Prenatal Testing Protocol in an Integrated, Multihospital Health System

OBJECTIVES

When our institution grew into an integrated multihospital health system, we were faced with the need to standardize laboratory processes, including blood bank processes, across all locations. The purpose of this article is to describe our experience of standardizing the protocols for prenatal testing.

METHODS

For each hospital in the system, we established service tiers to define tests offered on site or referred to another location. For each prenatal test, we examined the related processes for ways to improve uniformity, efficiency, and reliability. Throughout this process of standardization, we collaborated with the clinical services to gain concurrence on the interpretation and reporting of results.

RESULTS

We created and implemented a uniform protocol for testing prenatal patients. The protocol standardized the definition of critical titer, instituted criteria to identify passively acquired anti-D, and established a process for the follow-up of women with inconsistent serologic results on Rh(D) typing.

CONCLUSIONS

Close collaboration with the clinical services ensured that our testing protocol is aligned with the needs of the integrated obstetrics service in the health system. The approach described in this article may provide a plan outline for pathologists facing similar challenges at other integrated health systems.

Practice Modification for Pandemics: A Model for Surge Planning in Obstetrics

This review highlights proposed pandemic-adjusted modifications in obstetric care, with discussion of risks and benefits based on available evidence. We suggest best practices for balancing community-mitigation efforts with appropriate care of obstetric patients.

Self-managed abortion

PURPOSE OF REVIEW

To review the current state of self-managed or self-induced abortion in the United States and the emerging legal, political, and research questions surrounding this issue.

RECENT FINDINGS

With the exponential rise of restrictive antiabortion laws in the United States, it has become increasingly difficult to access safe and legal abortion services. One response to this hostile environment for reproductive care access is an increased interest in methods of self-induced or self-managed abortions, primarily by medications sourced outside the medical setting. Medication abortion is established as a safe and effective method of ending a pregnancy. Compared with clinic-based care, the two most pressing concerns regarding the safety of self-managed abortion are that people seeking abortion will incorrectly self-identifying as appropriate candidates and that they will not know or be able to access medical care if needed. There is therefore an increasing need for medical providers to learn about and researchers to evaluate the incidence, safety and efficacy of self-management of abortion. Simultaneously, reproductive law experts must continue to develop and educate on the legal frameworks to protect and decriminalize people seeking self-managed abortion as well as their care providers.

SUMMARY

Emerging research suggests that abortion outside the medical setting, or self-managed abortion, is an overall safe and effective way to end a pregnancy. However, significant legal barriers and stigma remain. The safest environment for self-managed abortion (SMA) is one where accurate information is available, medical care is accessible when needed, and all methods of abortion remain legal.

Antenatal and postpartum prevention of Rh alloimmunization: A systematic review and GRADE analysis

BACKGROUND

Existing systematic reviews of Rh immunoprophylaxis include only data from randomized controlled trials, have dated searches, and some do not report on all domains of risk of bias or evaluate the certainty of the evidence. Our objective was to perform an updated review, by including new trials, any comparative observational studies, and assessing the certainty of the evidence using the GRADE framework.

METHODS

We searched MEDLINE, Embase and the Cochrane Library from 2000 to November 26, 2019. Relevant websites and bibliographies of systematic reviews and guidelines were searched for studies published before 2000. Outcomes of interest were sensitization and adverse events. Risk of bias was evaluated with the Cochrane tool and ROBINS-I. The certainty of the evidence was performed using the GRADE framework.

RESULTS

Thirteen randomized trials and eight comparative cohort studies were identified, evaluating 12 comparisons. Although there is some evidence of beneficial treatment effects (e.g., at 6-months postpartum, fewer women who received RhIg at delivery compared to no RhIg became sensitized [70 fewer sensitized women per 1,000 (95%CI: 67 to 71 fewer); I2 = 73%]), due to very low certainty of the evidence, the magnitude of the treatment effect may be overestimated. The certainty of the evidence was very low for most outcomes often due to high risk of bias (e.g., randomization method, allocation concealment, selective reporting) and imprecision (i.e., few events and small sample sizes). There is limited evidence on prophylaxis for invasive fetal procedures (e.g. amniocentesis) in the comparative literature, and few studies reported adverse events.

CONCLUSION

Serious risk of bias and low to very low certainty of the evidence is found in existing RCTs and comparative observational studies addressing optimal effectiveness of Rh immunoprophylaxis. Guideline development committees should exercise caution when assessing the strength of the recommendations that inform and influence clinical practice in this area.

Medical therapy to attenuate fetal anaemia in severe maternal red cell alloimmunisation

Haemolytic disease of the fetus and newborn (HDFN) remains an important cause of fetal mortality with potential neonatal and longer-term morbidity. HDFN is caused by maternal red cell alloimmunisation, with IgG antibodies crossing the placenta to destroy fetal erythroid cells expressing the involved antigen. Intrauterine fetal blood transfusion is the therapy of choice for severe fetal anaemia. Despite a strong evidence base and technical advances, invasive fetal therapy carries risk of miscarriage and preterm birth. Procedure-related risks are increased when invasive, in utero transfusion is instituted prior to 22 weeks to treat severe early-onset fetal anaemia. This review focuses upon this cohort of HDFN and discusses intravenous immunoglobin (IVIg) and novel monoclonal antibody (M281, nipocalimab) treatments which, if started at the end of the first trimester, may attenuate the transplacental passage and fetal effects of IgG antibodies. Such therapy has the ability to improve fetal survival in this severe presentation of HDFN when early in utero transfusion may be required and may have wider implications for the perinatal management in general.

Medication Abortion Up to 70 Days of Gestation

Medication abortion, also referred to as medical abortion, is a safe and effective method of providing abortion. Medication abortion involves the use of medicines rather than uterine aspiration to induce an abortion. The U.S. Food and Drug Administration (FDA)-approved medication abortion regimen includes mifepristone and misoprostol. The purpose of this document is to provide updated evidence-based guidance on the provision of medication abortion up to 70 days (or 10 weeks) of gestation. Information about medication abortion after 70 days of gestation is provided in other ACOG publications [1].

Clinical practices and outcomes of RhD immunoglobulin prophylaxis following large-volume fetomaternal haemorrhage in Queensland, Australia

BACKGROUND

Guidelines for laboratory assessment of fetomaternal haemorrhage (FMH) was published by the Australian and New Zealand Society of Blood Transfusion (ANZSBT) in 2002. However, data on adherence by practitioners and clinical outcomes are lacking.

AIMS

The primary objective is to examine the follow-up testing and dosing of additional RhD immunoglobulin in RhD negative women who experienced large-volume FMH for whom additional intravenous RhD immunoglobulin was requested in Queensland, Australia. The secondary objectives are to examine the rate and risk factors of RhD alloimmunisation in these women.

MATERIALS AND METHODS

RhD negative women with FMH >6 mL for whom additional dose(s) of intravenous RhD immunoglobulin was requested through Australian Red Cross Lifeblood from February 2007 to February 2018 were identified. For each patient, the volume of FMH, methods and timing of FMH quantitation, dose of RhD immunoglobulin, maternal and cord blood groups were analysed against the corresponding antibody screen and identification.

RESULTS

Following FMH >6 mL, only 15% and 11.5% of cases adhered to current ANZSBT guideline on follow-up testing and supplemental RhD immunoglobulin dosing respectively. Despite the provision of single supplemental RhD immunoglobulin at a ratio of 100 IU to 1 mL fetal red cells, the rate of RhD alloimmunisation in RhD negative women with RhD positive fetus or fetus of unknown RhD status following FMH >6 mL is at least 4%.

CONCLUSIONS

Poor compliance with guidelines for follow-up and management of large-volume FMH may contribute to increased risk of RhD alloimmunisation. Further analysis of data is warranted.

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.

The concentration of fetal red blood cells in first-trimester pregnant women undergoing uterine aspiration is below the calculated threshold for Rh sensitization

OBJECTIVES

To calculate the minimum fetal red blood cell concentration required to cause maternal Rh sensitization; validate the use of a flow cytometry protocol below that concentration; preliminarily assess the concentrations of fetal red blood cells in pregnant women before and after uterine aspiration.

STUDY DESIGN

Using pre-existing literature, we calculated the lowest concentration of fetal red blood cells found to cause sensitization within adult female circulation. We validated a two-color flow cytometry protocol using fluorescently labeled antibodies to Hemoglobin F (expressed by fetal red blood cells and adult F cells) and Carbonic Anhydrase (expressed in red blood cells during the third trimester and postnatally) by titrating second trimester cord blood into non-pregnant adult blood. We applied this flow cytometry protocol in a prospective cohort study of 42 pregnant women at 5-12 weeks gestational age undergoing uterine aspiration for induced or spontaneous abortion.

RESULTS

The calculated threshold for causing Rh sensitization was 250 fetal red blood cells per 10 million total red blood cells. We showed a linear relationship between observed and expected fetal red blood cell fractions in titrated samples. Fetal red blood cell counts were more reliable when samples acquired by flow cytometry contained at least 1 million red blood cells. All 37 subjects with evaluable paired samples demonstrated fetal red blood cell concentrations below the calculated threshold for Rh sensitization both pre- and post-procedure. The fetal RBC concentrations increased from a mean of 4.5 (median 0, range 0-57) fetal RBCS pre- to a mean of 8.6 (median 2, range 0-32) fetal RBCs post- per 10 million total RBCs (p < 0.001).

CONCLUSIONS

Flow cytometry was capable of separately quantifying fetal red blood cells and maternal F cells to very dilute concentrations. Fetal red blood cell exposure in the first trimester was well below the calculated threshold for maternal Rh sensitization in our cohort. Larger studies are warranted to confirm our pilot study findings, fill this evidence gap and inform universal guidelines for administering Rh immunoglobulin after first trimester uterine aspiration.

IMPLICATIONS

Fetal red blood cell exposure following first trimester uterine aspiration is well below the calculated threshold for maternal Rh sensitization in our cohort.

Red cell alloimmunization: A 2020 update

Management of maternal red cell alloimmunization has been revolutionized over the last 60 years. Advances in the prevention, screening, diagnosis, and treatment of alloimmune-induced fetal anemia make this condition an exemplar for contemporary practice in fetal therapy. Since survival is now an expectation, attention has turned to optimization of long-term outcomes following an alloimmunized pregnancy. In this review, the current management of red cell alloimmunization is described. Current research and future directions are discussed with particular emphasis on later life outcomes after alloimmune fetal anemia.

Very Prolonged Anti-D: Confusion Surrounding Alloimmunization After Extra Rh Immunoglobulin: A Case Report

BACKGROUND

Rh immunoglobulin (RhIg) is usually detectable a maximum of 12 to 14 weeks after administration. Positive antibodies beyond this time frame suggests alloimmunization.

CASE

A woman had three pregnancies over a 6-month period, with two first-trimester losses. She received RhIg in the first pregnancy but not in the second. Two months after the second loss, in her third pregnancy, she received RhIg at week 6 due to first-trimester bleeding. She was subsequently anti-D antibody positive up to week 28 with antibodies too low to titre, leading to confusion about whether alloimmunization had occurred.

CONCLUSION

Rh Ig administration led to positive anti-D antibodies lasting 22 weeks, suggesting keeping this differential diagnosis in mind when suspecting alloimmunization with positive antibodies at levels too low to titre.

Transfusion Medicine Equations Made Internet Accessible

Multiple mathematical equations inform the practice of transfusion medicine. These equations apply to a wide range of topics: dosage of blood products, calculation of fluid volumes, and even specific treatment decisions (e.g. corrected count increment for determination of platelet refractoriness). The calculation of these equations can be complicated, prone to error, and time-consuming. A trusted source is needed to accurately perform these calculations 24 hours a day without error and without monetary cost. We sought to build internet-enabled calculators relevant to the practice of transfusion medicine. We partnered with MDCalc, an online host of medical calculators with 1 million monthly users in 196 countries, to design and host the calculators. The calculators guide users in the application of transfusion medicine equations by providing indications for use, inputs for the equations variables, error-checking, warnings for bad inputs, and interpretive guidance of the result. The following calculators were built: blood volume, corrected count increment (CCI), plasma dosage, cryoprecipitated antihemophilic factor dosage, approximate number of units for compatibility testing, maternal-fetal hemorrhage Rh(D) immune globulin dosage, intrauterine RBC transfusion dosage, neonatal polycythemia partial exchange, theoretical removal of a substance by plasmapheresis, sickle cell RBC exchange volume, peripheral blood stem cell collection, and a calculator relevant to donor lymphocyte infusion. Clinicians can now utilize this reputable and highly visible online source to access these common transfusion medicine equations at any time with an internet-enabled device (https://www.mdcalc.com/search?filter=transfusion+medicine).

Prehospital Transfusion of Low-Titer O + Whole Blood for Severe Maternal Hemorrhage: A Case Report

Introduction: Beginning in 2017, multiple stakeholders within the Southwest Texas Regional Advisory Council for Trauma collaborated to incorporate cold-stored low-titer O RhD-positive whole blood (LTO + WB) into all phases of their trauma system, including the prehospital phase of care. Although the program was initially focused on trauma resuscitation, it was expanded to included non-traumatic hemorrhagic shock patients that may benefit from whole blood resuscitation.Case Report: We report the case of a patient with severe maternal hemorrhage secondary to placenta accreta who received a prehospital transfusion of LTO + WB. We believe this to be the first reported case of post-partum hemorrhage resuscitated out of hospital with whole blood.Discussion: This case highlights the potential benefits of a prehospital whole blood program as well as the controversy surrounding a LTO + WB program that includes females of childbearing age.

The continuing burden of Rh disease 50 years after the introduction of anti-Rh(D) immunoglobin prophylaxis: call to action

Severe morbidity and death because of Rh disease have only been reduced by approximately 50% globally during the last 50 years, despite the advent of anti-Rh(D) immunoglobin prophylaxis, which has resulted in >160,000 perinatal deaths and 100,000 disabilities annually. This apparent failure to take appropriate preventive measures is of great concern. Thus, there is a great need to do much better. We wish to draw attention to the unnecessary continuing burden of Rh disease, to discuss some of the reasons for this failure, and to provide suggestions for a better way forward.

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.

Complications in Early Pregnancy

Early in pregnancy women frequently experience nausea, vomiting, and vaginal bleeding. Nausea and vomiting can be mild, managed by dietary modifications and medications, or severe, requiring intravenous fluids and medications. Care should be used when selecting medications for nausea to avoid additional side effects or potential harm to the developing fetus. When evaluating vaginal bleeding in early pregnancy, ectopic pregnancy must be ruled out. If an intrauterine pregnancy is seen, threatened miscarriage should be considered and the patient appropriately counseled. If neither intrauterine pregnancy nor ectopic pregnancy can be established, a management algorithm for pregnancy of unknown location is presented.