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.

Maternal and fetal outcomes of intraplacental choriocarcinoma complicated by fetomaternal hemorrhage: a systematic review.

INTRODUCTION: Intraplacental choriocarcinoma is a gestational trophoblastic neoplasia located within the placenta. Due to the usual silent presentation, more than half of the cases are diagnosed incidentally. It has been demonstrated that this pathology is linked to feto-maternal hemorrhage (FMH), stillbirth, and intrauterine growth restriction. The aim of our review was to establish if there are recurrent signs that might lead to an early diagnosis and better management in cases complicated by FMH. MATERIALS AND METHODS: We performed a systematic review of the literature from 2000 up to March 2023. The adopted research strategy included the following terms: (gestational choriocarcinoma obstetrics outcome) AND (intraplacental choriocarcinoma) AND (gestational choriocarcinoma). The MEDLINE (PubMed), Google Scholar, and Scopus databases were searched. RESULTS: The research strategy identified 19 cases of FMH coexisting with intraplacental choriocarcinoma (IC), as described in 17 studies. The perinatal mortality rate was 36.8%. In eight cases, histological diagnosis of IC was made post-delivery. Metastatic lesions were found in 75% (6/8) of described cases. One case of maternal death has been described. Chemotherapy was necessary in seven cases. Sporadical prenatal ultrasound signs were described. DISCUSSION: The diagnosis of IC is usually delayed, mostly due to aspecific symptoms and signs. Histological analysis of the placenta, when not routinely performed, should be performed when warning symptoms are encountered. The maternal prognosis was good, with a mortality rate of 5.5%. A fertility-sparing approach is always possible even in the presence of metastasis. Chemotherapy seems to be useful in cases of maternal and neonatal metastasis.

Prenatal diagnosis of fetomaternal hemorrhage by a novel hydrogel fluoroimmunoassay that accurately quantifies fetal haemoglobin.

Objective: Fetomaternal hemorrhage (FMH) is an alloimmunization resulting caused by the incompatibility between fetal and maternal blood. For the prevention of newborn haemolytic disease (HDN), it is crucial to quantify the amount of fetomaternal hemorrhage. However, the classical Kleihauer-Betke test (K-B test) for detecting fetomaternal hemorrhage is limited by experimental tools and conditions and is not suitable for routine clinical use. Consequently, the method of prenatal diagnosis of fetomaternal hemorrhage applicable to the clinic is a topic worthy of further study. Therefore, it is worthwhile to further investigation on the clinically applicable prenatal diagnosis method for fetomaternal hemorrhage. Methods: This experiment demonstrates hydrogel's ability to separate sensitized red blood cells from soluble antibodies. Using flow cytometry the fluorescence values of sensitized red blood cells and fluorophore-labeled antibodies were measured, and the testing steps for the detection products of a novel technology were determined. The properties of a hydrogel fluoroimmunoassay were evaluated by distinguishing between the amounts of fetal and adult haemoglobin. The precision of this technology is evaluated using the Kleihauer-Betke test as a comparison. Results: This experiment compared the detection of haemoglobin fluorescence in adults (n = 2) and fetuses (n = 6). At the same time, the fluorescence intensity of different fetal haemoglobin (HbF) in adult haemoglobin (HbA) was calculated. The fluorescence value is 1.6% when the fetal hemoglobin concentration is 0.1%. Conclusion: The novel hydrogel fluoroimmunoassay can accurately determine the fluorescence intensity by flow cytometry to differentiate fetal haemoglobin from adult haemoglobin, quantitatively prenatally diagnose fetal haemoglobin, address the incompatibility between fetal and maternal blood types, and prevent alloimmunization.

Massive fetomaternal hemorrhage in a monochorionic-diamniotic twin pregnancy: a case report.

Fetomaternal hemorrhage (FMH) result into severe, life-threatening fetal anemia and cause intrauterine death of the fetus. It is tough for an early diagnosis of FMH before pregnancy and few authors reported FMH in a twin pregnancy. Therefore, we reported a case of massive FMH. The patient felt a decrease in fetal movements at 33+5 gestational weeks. Cardiotocography showed sinusoidal heart rate patterns in one fetus. The fetal hemoglobin level in maternal blood was 6.4% (normal range for single pregnancy, 0.0%-2.0%). Since the patient was diagnosed with fetal distress, cesarean section was performed and both babies delivered to receive neonatal treatment. Severe anemia was apparent in both neonates, based on red blood cell count, hemoglobin concentration, and hematocrit of 0.75 × 1012/L and 0.61 × 1012/L, 2.8 g/dL and 2.4 g/dL, and 10.0% and 8.4%, respectively. The neonates were admitted to the intensive care unit for prematurity care and presently are well. In our experience, an early diagnosis of FMH contributed to saving fetus. Obstetricians should highlight fetal movements counting to every patient. Once massive FMH occurs in monochorionic twins, both fetuses may develop severe anemia and require emergency intervention.

Management and Follow-up of Massive Fetomaternal Hemorrhage Requiring High-Dose Rh Immune Globulin: A Case Report.

OBJECTIVES: Massive fetomaternal hemorrhage (FMH) is rare and reported to be the cause in approximately 3% of all fetal deaths. Maternal management of massive FMH includes prevention of Rh(D) alloimmunization in Rh(D)-negative mothers by administration of Rh(D) immune globulin (RhIG). METHODS: We describe a case of a 30-year-old O-negative, primigravida woman who presented at 38 weeks of gestation with decreased fetal movements. She underwent an emergency cesarean section and delivered an O-positive baby girl who died shortly after birth. RESULTS: The patient's FMH screen was positive, with a Kleihauer-Betke test demonstrating 10.7% fetal blood in maternal circulation. The calculated dose of 6,300 µg RhIG was given prior to discharge over 2 days using an intravenous (IV) preparation. Antibody screening a week after discharge showed anti-D and anti-C. The anti-C was attributed to acquired passive immunity from the large dose of RhIG. Anti-C reactivity waned and was negative at 6 months, but the anti-D pattern persisted at 9 months postdelivery. Negative antibody screens were noted at 12 and 14 months. CONCLUSIONS: This case highlights the immunohematology challenges of IV RhIG as well as the success in preventing alloimmunization with IV RhIG given the patient's complete resolution of anti-C and no anti-D formation, with a subsequent healthy pregnancy.

Management of Wrong Blood Transfusion to an RhD Negative Woman in Labor.

Blood transfusion is life-saving in massive hemorrhage. Before pre-transfusion tests with ABO and RhD typing results are available, O RhD negative packed red blood cell (PRBC) units are used without cross-matching in emergency. RhD negative girls and women of child-bearing age should always receive RhD negative blood transfusions to prevent RhD-alloimmunization because anti-D-related hemolytic disease of fetus and newborn (HDFN) can result in mild to severe anemia, and in a worst-case scenario death of an RhD positive fetus and/or newborn. However, "wrong blood to wrong patient" happens unintentionally. Here we report an emergency blood transfusion with one unit of RhD positive PRBCs to an RhD negative young woman when estimated blood loss was 2500 mL during delivery and surgical removal of retained placenta. Realizing the mistake, management with high dose anti-D immunoglobulin (Ig) was initiated to remove the RhD positive red blood cells (RBCs) from the patient's circulation. Such mitigation is recommended only for girls and women of child-bearing age. Follow-up was performed by flow cytometry until RhD positive RBCs were no longer detected. Ten months after the delivery, antibody screening was negative. However, we still do not know whether we managed to prevent RhD-alloimmunization.

Society of Family Planning committee consensus on Rh testing in early pregnancy.

Historical evidence that fetal red blood cell (RBC) exposure during early spontaneous or induced abortion can cause maternal Rh sensitization is limited. A close reading of these studies indicates that forgoing Rh immunoglobulin administration before 12weeks gestation is highly unlikely to increase risk of Rh (D) antibody development, and recent studies indicate that fetal RBC exposure during aspiration abortion <12 weeks gestation is below the calculated threshold to cause maternal Rh sensitization, and the amount of fetomaternal hemorrhage during dilation and evacuation procedures up to 18weeks gestation is adequately treated with 100mcg of Rh immunoglobulin. We provide updated recommendations for Rh immunoglobulin administration based on this new evidence.

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%.

Severe neonatal anemia affected by massive fetomaternal hemorrhage: a single-center retrospective observational study.

OBJECTIVES: Massive fetomaternal hemorrhage (FMH) is a rare but sometimes life-threatening event, and surviving neonates may suffer major neurological complications. Severe neonatal anemia (SNA) affected by massive FMH is less reported in the literature. This study aims to explore the clinical characteristics, laboratory diagnoses, treatments and outcomes of SNA affected by massive FMH. METHODS: Data were collected retrospectively from the hospital's electronic medical record system. All neonates born in the hospital and admitted to the neonatal unit diagnosed as SNA affected by massive FMH from 1 January 2013 to 31 June 2017 were included. RESULTS: A total of 8 cases of SNA affected by FMH were identified among 6825 neonates admitted to the neonatal unit. They all presented with pallor but without hydrops at birth. Median gestational age and birthweight were 375/7 (360/7‒401/7) weeks and 2,625 (2300‒3050) g, respectively. Median hemoglobin level was 39.5 (25‒53) g/L at birth and 109.5 (94-127) g/L at discharge. Median maternal serum alpha-fetoprotein (AFP) was 3958.5 (1606‒14,330) ng/mL, which was significantly increased. Three out of eight cases manifested as antenatal decreased fetal movement. Only 1 with the lowest initial hemoglobin 25 g/L manifested as characteristic sinusoidal fetal heart rate tracing and suffered severe neonatal asphyxia and hypovolemic shock. Having experienced resuscitation, he was admitted to the neonatal unit and received twice transfusion of cross-matched red blood cells there. Another case with the initial hemoglobin 45 g/L received positive pressure ventilation and once transfusion. All cases were successfully discharged with a median hospital stay of 8 (5-12) days. Follow-up was available for 6 (75%) of 8 neonates (age range 13 months to 50 months), and all infants were observed to be in good condition with normal neurological status. In our series of eight cases, there were no neonatal deaths. CONCLUSION: This study strengthens the idea that maternal AFP testing is valuable to confirm massive fetomaternal hemorrhage. Surviving neonates of massive FMH might have a good outcome despite severe anemia at birth.

Performance of the Kleihauer Betke test in the prediction of neonatal anemia.

OBJECTIVES: The aim of this study was to correlate antenatal Kleihauer (KT) test results with fetal hemoglobin at birth to find a threshold for predicting severe fetal anemia. The secondary objectives were to assess the impact of KT on obstetric management and to study the correlation between the middle cerebral artery peack systolic velocity and fetal anemia. RESULTS: One thousand forty-six KT were positive over the 10-year period, but only 147 were included from 88 patients, of which 17 fetuses were anemic. Demographic and obstetric characteristics were similar between anemic and non-anemic groups. As regards new-born, there was a higher risk of prematurity among anemic as long as a lower birth rate in accordance. While a negative correlation was observed between KT and hemoglobin at birth, no KT upper threshold could be found that was both sensitive and specific. In addition, there was no case of fetal anemia when KT was repeated, even though it increased. KT showed little usefulness in obstetrics management to help improving neonatal care for anemia. Conversely, the MCA PSV demonstrated good performance in this matter and the ROC curve area was 0.91 (figure). DISCUSSION: Feto-maternal hemorrhage is a rare but grave pathology which could lead to anemia. The most common clinical sign is reduced fetal movement and it was the main indication to perform a KT. Cardiotocography patterns suggestive of anemia are sinusoidal, micro-oscillatory and non-reactive monitoring. Ultrasound features were polyhydramnios, hydrop fetalis and increased MCA peack systolic velocity. KT was correlated with MCA PSV and with hemoglobin level at birth. However, the latter showed a better diagnostic performance. MCA PSV measurement is a powerful test to screen for fetal anemia, and should be part of the regular training of obstetricians. Indeed, this technic gives immediate and reliable results, while those of KT are delayed. CONCLUSION: The KT should not be used as a tool to screen for fetal anemia but rather as a test to explain a fetal anemia. However, the MCA PSV is reliable in this matter and give immediate result, thus obstetrician should be trained to routinely perform it.

Fetomaternal hemorrhage: a clue to intraplacental choriocarcinoma and neonatal malignancy.

Fetomaternal hemorrhage (FMH) is a known cause of neonatal anemia due to fetal blood loss to the maternal circulation, occurring when the maternal-fetal barrier is disrupted. Several causes must be considered, although in most cases the etiology remains unknown. Intraplacental choriocarcinoma (ICC) is a rare entity and has been related with massive FMH, intrauterine fetal demise, severe neonatal anemia and metastatic choriocarcinoma in both mother and infant. There are 25 cases of histopathologically confirmed ICC complicated with FMH described in the literature. Because FMH occurs unexpectedly and the majority of patients with ICC are asymptomatic, this diagnosis may be missed. Once FMH is confirmed, underlying malignancy should be kept in mind. The authors present a case report of severe neonatal anemia following FMH related to ICC and highlight the importance of serum ß-hCG monitoring in cases of massive FMH.

Application of flow cytometry in transfusion medicine: The Sanjay Gandhi Post Graduate Institute of Medical Sciences, India experience.

The application of flow cytometry (FC) is diverse and this powerful tool in used in multiple disciplines such as molecular biology, immunology, cancer biology, virology, and infectious disease screening. FC analyzes a single cell or a particle very rapidly as they flow past single or multiple lasers while suspended in buffered solution. FC has a great impact in the field of transfusion medicine (TM) due to its ability to analyze individual cell population and cell epitopes by sensitive, reproducible, and objective methodologies. The main uses of FC in TM are detection of fetomaternal hemorrhage, diagnosis of paroxysmal nocturnal hemoglobinuria, quantification of D antigen, detection of platelet antibody, quality control of blood components, for example, residual leukocyte counts and evaluation of CD34-positive hematopoietic progenitor cells in stem cell grafts. In recent years, FC has been implemented as an alternative method for the detection and characterization of red cell autoantibodies in autoimmune hemolytic anemia. Many workers considered FC as a very good complement when aberrant expression of various erythrocyte antigens needs to be elucidated. It has been extensively used in the resolution of ABO discrepancies and chimerism study. FC has also been used successfully in various platelet immunological studies. In the recent past, FC has been used in several studies to assess the platelet storage lesions and elucidate granulocyte/monocyte integrity and immunology. FC analysis of CD34+ stem cells is now the method of choice to determine the dosage of the collected progenitor cells. The technique is vastly used to evaluate residual leukocytes in leukodepleted blood components. We conclude that flow cytometers are becoming smaller, cheaper, and more user-friendly and are available in many routine laboratories. FC represents a highly innovative technique for many common diagnostic and scientific fields in TM. Finally, it is the tool of choice to develop and optimize new cellular and immunotherapeutic trials.

Investigation on the incidence and risk factors of fetomaternal hemorrhage syndrome in pregnant women in Changsha / 中国输血杂志

【Objective】 To investigate the incidence and possible risk factors of FMH among pregnant women in Changsha. 【Methods】 A total of pregnant women (6~42 weeks of gestation) who underwent prenatal examinations in our hospital from June 2019 to December 2020 were enrolled as subjects. In this study, the modified Kleihauer-Betke (K-B) test was used for preliminary screening and flow cytometry was applied to confirme initially positive samples to evaluate the incidence of FMH and estimate fetal blood loss. The logistic regression analysis was used to study the risk factors of FMH. 【Results】 The incidence of FMH in pregnant women was 10.45% (183/1 752), the average volume of fetal blood loss was (2.50±3.87)mL, and 0.11% (2/1 752) of the fetal losed blood > 30 mL. Univariate analysis showed that age, twin pregnancy, pregnancy complicated with uterine fibroids, in vitro fertilization, fetal growth restriction, preeclampsia, and number of pregnancies may be risk factors for FMH. Multivariate analysis showed that twin pregnancy (OR 2.274, 95%CI: 1.135-4.458, P<0.05) and preeclampsia (OR 2.341, 95%CI: 1.082-4.837, P<0.05) were independent risk factors for FMH. 【Conclusion】 Maternal age and various physiological and pathological factors during pregnancy may be associated with the risk of FMH, especially twin pregnancy and pre-eclampsia are independent risk factors for FMH.

Severe Neonatal Anemia Due to Spontaneous Massive Fetomaternal Hemorrhage at Term: An Illustrative Case with Suspected Antenatal Diagnosis and Brief Review of Current Knowledge.

Fetomaternal hemorrhage is defined as transfer of fetal blood into placental circulation and therefore into maternal circulation during pregnancy, and represents an important contributor to intrauterine fetal demise and neonatal death. The condition is rarely diagnosed prenatally because clinical findings are often nonspecific, and it is unpredictable. In this paper we present an illustrative case of massive spontaneous fetomaternal hemorrhage where the diagnosis was highly suspected antenatally based on maternal reported reduced fetal movements, abnormal suggestive cardiotocographic trace, and increased peak systolic velocity in the fetal middle cerebral artery. We discuss obstetrical and neonatal management and review the current knowledge in the literature. Maintaining a high index of suspicion for this condition allows the obstetrician to plan for adequate diagnostic tests, arrange intrauterine treatment or delivery, and prepare the neonatal team.

A very preterm infant born to mother of mirror syndrome secondary to fetomaternal hemorrhage: a case report.

BACKGROUND: Mirror syndrome (MS) is defined as maternal edema with fetal hydrops and placental edema with different etiologies, such as rhesus isoimmunization and twin-twin transfusion syndrome. Herein, we showcased a unique MS case secondary to fetomaternal hemorrhage (FMH). CASE PRESENTATION: A 32-year-old gravida 2 para 0 woman diagnosed with fetal hydrops was admitted to our hospital. Maternal laboratory tests revealed anemia, slightly increased creatinine and uric acid levels, hypoproteinemia, and significantly increased alpha-fetoprotein and hemoglobin-F levels. Therefore, FMH was diagnosed initially. Two days after admission, the woman had unexpectedly progressive anasarca and started to feel chest distress, palpitations, lethargy, and oliguria, and MS was suspected. An emergency cesarean section was performed to terminate the pregnancy. The maternal clinical symptoms and laboratory tests rapidly improved after delivery. A very preterm infant with a 2080-g birthweight at 31 weeks gestation survived after emergency cesarean section, active resuscitation, emergency blood transfusion, abdominocentesis, and advanced life support. CONCLUSIONS: FMH could develop into MS, providing new insights into the etiology of MS. Once MS is diagnosed, emergency cesarean section might be an alternative treatment. The very preterm infant survived with a favorable long-term outcome, and a well-trained perinatal work team is needed for such cases.

Hemolytic Disease of the Newborn: A Review of Current Trends and Prospects.

Hemolytic disease of the newborn (HDN), also known as Erythroblastosis fetalis, is a hemolytic condition that predominantly affects rhesus-positive fetuses and infants born to rhesus-negative mothers. The pathophysiology of HDN begins with maternal antibodies attacking fetal red blood cells following alloimmunization due to rhesus or ABO incompatibility between the maternal and fetal blood. Previously, HDN was known to cause fetal death in 1% of all pregnancies, but with the advent of immunoprophylactic therapies, the condition can be currently fairly well managed with fewer complications if diagnosed early. Diagnosis calls for extensive history taking, physical examination, serological studies, and imaging modalities such as pelvic ultrasound scans. To prevent the disease, earlier intravenous immunoglobulin (IVIG) should be given to pregnant Rh- women who have not been sensitized. It is also vital to understand prospective complications such as severe hyperbilirubinemia and develop appropriate remedies. Because of its great incidence and nature, HDN has been thoroughly explored, and more studies are being conducted each year, revealing new insights about the condition. This review covers the disorder's etiology, diagnosis, and management, including the most current findings as of 2021, as well as trends and prospects, to help in future research and evidence-based medical practice.

Red cell alloimmunization among antenatal women attending tertiary care center in Jamnagar, Gujarat, India.

BACKGROUND: The following study was conducted to measure the presence of alloantibodies of Rh and other blood group antigens produced due to fetomaternal hemorrhage in all antenatal women as well as those leading to hemolytic disease of fetus and newborn; presenting to a tertiary care center, G.G. Government Hospital, Jamnagar, Gujarat, India, between April 2014 and March 2016 (2 years). MATERIALS AND METHODS: All multiparous women irrespective of their period of gestation or obstetrics history were included whereas those having taken anti-D immunoprophylaxis or with a history of blood transfusion were excluded. Antibody screening and identification were done using Bio-Rad ID microtyping system. RESULTS: Out of total 8920 multigravida females, 8488 were D-antigen positive whereas 432 were D-antigen negative. A total of 126 antibodies among 117 females (1.31%) were found; out of them, 33 were found in D-antigen positive females (0.39%) and 84 in D-antigen negative ones (19.44%) looking at overall frequency of other antibodies such as anti-C: 9, anti-c: 9, anti-E: 13, anti-Cw: 1, anti-M: 5, anti-S: 8, anti-Fya: 3, and anti-D: 78; it was found that anti-D is the most common. CONCLUSION: The rate of alloimmunization in D-antigen negative women was found to be very high as compared to other studies in western region; hence, strict follow-up of immunoprophylaxis of all Rh D-negative women needs to be taken care of. Apart from this, D-antigen-positive women also show alloimmunization against various antigens giving the prevalence of 0.39%; hence, it should be mandatory that there should be one standard universal protocol for screening of all antenatal women.

Time points and risk factors for RhD immunizations after the implementation of targeted routine antenatal anti-D prophylaxis: A retrospective nationwide cohort study.

INTRODUCTION: Targeted routine antenatal anti-D prophylaxis was introduced to the national prophylaxis program in Finland in late 2013. The aim of this study was to assess the incidence, time-points, and risk factors for Rhesus D immunization after the implementation of routine antenatal anti-D prophylaxis, in all women in Finland with antenatal anti-D antibodies detected in 2014-2017. MATERIAL AND METHODS: In a nationwide population-based retrospective cohort study, the incidence, time-points, and risk factors of anti-D immunizations were analyzed. Information on antenatal screening was obtained from the Finnish Red Cross Blood Service database, and obstetric data from hospital records and the Finnish Medical Birth Register. RESULTS: The study included a total of 228 women (197 with complete data for all pregnancies). After the implementation of routine antenatal anti-D prophylaxis, the prevalence of pregnancies with anti-D antibodies decreased from 1.52% in 2014 to 0.88% in 2017, and the corresponding incidence of new immunizations decreased from 0.33% to 0.10%. Time-points for detection of new anti-D antibodies before and after 2014 were the first screening sample at 8-12 weeks of gestation in 52% vs 19%, the second sample at 24-26 weeks in 20% vs 50%, and the third screening at 36 weeks in 28% vs 32%. CONCLUSIONS: The incidence of new anti-D immunizations decreased as expected after the implementation of routine antenatal anti-D prophylaxis. True failures are rare and they mainly occur when the prophylaxis is not given appropriately, suggesting a need for constant education of healthcare professionals on the subject.