Development of a new staining protocol for the Kleihauer-Betke test to facilitate the reading of difficult cases.

BACKGROUND: The Kleihauer-Betke (KB) test allows the detection of fetal red blood cells (containing fetal hemoglobin, HbF) in the maternal blood to identify and quantify potential fetal-maternal hemorrhages. In certain cases, detecting fetal red blood cells with conventional staining is difficult. False-positive results or overestimation of the quantity of fetal red blood cells may occur in cases of maternal hemoglobinopathy. In this study, we developed a new staining protocol to facilitate the reading of difficult smears and improve the precision of the quantification of fetal red blood cells; we also analyzed the performance of this new method. This study assessed blood samples with and without hemoglobin abnormalities, which present difficulties when interpreting the KB test. METHODS: The new staining formula is based on an improved elution technique and the use of a different stain instead of hematoxylin. To test this staining method, 16 samples from patients with abnormal hemoglobin electrophoresis and 14 samples from patients with normal hemoglobin electrophoresis were analyzed using the KB test with the classical staining method and the new staining method. In addition, a second series was prepared using the same samples spiked with fetal red blood cells from newborn blood, to compare the accuracy of the two methods in identifying fetal red blood cells. RESULTS: In the 60 slides analyzed with both staining methods, we found that the new technique improved the accuracy from 78 to 85%; lowered the coefficient of variation between the operators, which decreased from 20.7% to 12.7%; increased the specificity in our population from 56 to 70%; and decreased the number of false-positive cases by 30%. CONCLUSIONS: We successfully developed a new staining technique that facilitates the reading of difficult slides and improves the specificity of the detection of fetal red blood cells. This technique is recommended as a secondary method to use before sending the sample for additional exploration.

Management of the Pregnant Trauma Patient: A Systematic Literature Review.

INTRODUCTION: Trauma during pregnancy is the leading cause of non-obstetric maternal death and complicates up to 5%-7% of pregnancies. This systematic review without meta-analysis explores the current literature regarding the assessment and management of pregnant trauma patients to provide evidence-based recommendations to guide the general surgeon regarding the prognostic value of laboratory testing including Kleihauer-Betke testing, duration of maternal and fetal monitoring, the use of tranexamic acid, the safety of radiographic studies, and the utility of perimortem cesarean section to improve maternal and fetal mortality. MATERIALS AND METHODS: A systematic search of MEDLINE (Ovid), the Cochrane Library (Wiley), and Embase (Elsevier) was performed. The reference lists of included studies were reviewed for relevant citations. RESULTS: Of the 45 studies included in this review, there was reasonable evidence to suggest that the minimally injured pregnant trauma patient should be observed for a minimum of 4 h, CT scans to rule out traumatic injury are necessary and safe, perimortem cesarean sections should be performed as soon as maternal cardiac arrest occurs. CONCLUSIONS: We recommend delivery by perimortem cesarean section as soon as possible after maternal cardiac arrest, to provide TXA to the hemorrhaging pregnant trauma patient, to obtain trauma CT scans as indicated, and to observe the injured pregnant patient for a minimum of at least 4 h. Additional high-quality studies focusing on the prognostic potential of KB tests and other laboratory studies are needed.

Fetomaternal hemorrhage: evaluation of recurrence within a large integrated healthcare system.

BACKGROUND: Fetomaternal hemorrhage is associated with severe fetal morbidity and mortality. The recurrence risk of fetomaternal hemorrhage is unknown. OBJECTIVE: We sought to establish the recurrence rate of fetomaternal hemorrhage in a large integrated healthcare system over a 10-year period. STUDY DESIGN: In this retrospective study within the Kaiser Permanente Northern California medical system, cases of fetomaternal hemorrhage were defined by either an elevated fetal hemoglobin level as determined by flow cytometry for a concerning pregnancy outcome (preterm delivery, perinatal demise, neonatal anemia, or transfusion within the first 2 days of life) or by perinatal demise with autopsy findings suggestive of fetomaternal hemorrhage. The outcomes of subsequent pregnancies were reviewed for features of recurrence. RESULTS: Within the 2008 to 2018 birth cohort of 375,864 pregnancies, flow cytometry testing for fetal hemoglobin levels was performed in 20,582 pregnancies. We identified 340 cases of fetomaternal hemorrhage (approximately 1 in 1100 births). Within the cohort of 340 affected pregnancies, perinatal loss was recorded for 80 (23.5%) pregnancies and 50 (14.7%) pregnancies delivered neonates who required transfusion. The affected patients had 225 subsequent pregnancies of which 210 were included in the analysis. Of these, 174 (82.9%) advanced beyond the threshold of viability and were delivered within our healthcare system. There was 1 case of recurrent fetomaternal hemorrhage identified. The recurrent case involved a spontaneous preterm delivery of an infant who was noted to have an elevated reticulocyte count but was clinically well. CONCLUSION: Within our large integrated healthcare system, approximately 1 in 1100 pregnancies was affected by fetomaternal hemorrhage within a 10-year period, which is comparable with previous studies. We identified 1 case of recurrence, yielding a recurrence rate of 0.5%. This infant did not have features of clinically important fetomaternal hemorrhage. This information can inform counseling of patients with affected pregnancies.

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.

The prevalence of an elevated F cell population in a maternal and gynaecology cohort.

OBJECTIVES: This study aimed to determine F cell prevalence in a cohort of maternal and gynaecology specimens using QuikQuant anti-HbF flow cytometry (FC) kit and to investigate if the presence of maternal F cells can lead to fetomaternal haemorrhage (FMH) overestimation. BACKGROUND: The gold standard to estimate FMH is the Kleihauer-Betke test (KBT). The KBT has proved to be insufficiently sensitive to detect low numbers of circulating fetal cells due to the presence of maternal F cells. At present, the prevalence of false positive KBT results due to raised maternal F cell population, defined as >5%, is poorly characterised. METHODS: A total of 120 specimens were tested for the presence of F cells and fetal cells by KBT and anti-HbF FC. The results calculated were compared to determine FMH overestimation. RESULTS: Of our cohort, 32% showed an elevated F cell population, of which 69% (27 of 39) were clinically significant according to KBT (>2 mL FMH). The mean FMH volumes by KBT and anti-HbF FC were 3·90 mL (0·20-35·40 mL) and 4·09 mL (0·20-9·70 mL), respectively. CONCLUSION: The study highlighted that an elevated F cell level could be found in the cohort tested, with an F cell level of >10% causing significant FMH overestimation by KBT.

The sensitivity of the Kleihauer-Betke test for placental abruption.

The Kleihauer-Betke (KB) test evaluates fetal blood in the maternal circulation, and is often used when placental abruption is suspected. At our centre, it is the protocol to perform a KB test in all suspected cases of abruption. We carried out a retrospective study of all cases of abruption that occurred at our centre over 6 years. Of the 68 confirmed cases of placental abruption, only three had positive KB tests, giving a sensitivity of only 4.4%. Thus, in the overwhelming majority of cases of confirmed abruption, the KB test was negative. Our findings indicate that the KB test has poor sensitivity for placental abruption and should not be used in the detection of abruption.

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.

Evaluation of passage of fetal erythrocytes into maternal circulation after invasive obstetric procedures.

AIM: The aim of this study was to evaluate the passage of fetal erythrocytes into the maternal circulation after invasive obstetric procedures, using the Kleihauer-Betke test, flow cytometry and α-fetoprotein concentration in maternal blood. MATERIAL AND METHODS: This was a prospective descriptive study on patients who underwent: amniocentesis, cordocentesis, chorionic villus sample, amniotic infusion, bladder drainage and ventricular-amniotic shunt to investigate the karyotype; treatment for hydrocephalus, oligohydramnios, obstructive uropathy and polyhydramnios; and investigation of lung maturity. Maternal blood samples were collected before and 60 min after the invasive obstetric procedure in order to evaluate the passage of fetal erythrocytes using the Kleihauer-Betke test, flow cytometry and α-fetoprotein concentration. RESULTS: In total, 43 invasive obstetric procedures were performed. The procedures performed were: 27 cases of amniocentesis (62.7%), seven cases of cordocentesis (16.2%), four chorionic villus samples (9.4%), two amniotic infusions (4.7%), two ventricular-amniotic shunts and one bladder drainage (2.3%). After one case of cordocentesis with two puncture attempts via the placenta, a significant increase in fetal erythrocytes was detected using the three methods. After another cordocentesis with one puncture via the placenta, a significant increase in fetal erythrocytes was detected using flow cytometry and α-fetoprotein concentration, but not through the Kleihauer-Betke test. The other 41 samples did not show any significant increase in fetal erythrocytes in the maternal blood. CONCLUSION: Invasive obstetric procedures performed during prenatal care are safe when performed by experienced professionals with the proper technique, with minimal chance of passage of fetal erythrocytes into the maternal compartment.

A Case of Massive Fetal-Maternal Hemorrhage: Lessons Learned in Diagnosis and Treatment.

The use of Rho(D) immune globulin in Rh-negative pregnant women has become standard of care, but many practicing clinicians do not know the dosing recommendations for this essential medication. In this article, we describe a case of a 15-year-old girl who presented with intrauterine fetal demise and was found to have massive fetomaternal hemorrhage. Kleihauer-Betke testing results indicated nearly 460 mL of fetal blood in the maternal circulation. The patient ultimately received 4800 µg of Rho(D) immune globulin, a dose that required close coordination with the obstetrical service and pharmacy. Although this is an unusual case of large-volume, potentially chronic, fetomaternal hemorrhage, it is also an excellent illustration of the principles for diagnosing this condition, as well as providing dosing guidelines for Rho(D) immunoglobulin to prevent alloimmunization.

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.

Evaluation of machine learning-driven automated Kleihauer-Betke counting: A method comparison study.

INTRODUCTION: The Kleihauer-Betke (KB) test is the diagnostic standard for the quantification of fetomaternal hemorrhage (FMH). Manual analysis of KB slides suffers from inter-observer and inter-laboratory variability and low efficiency. Flow cytometry provides accurate quantification of FMH with high efficiency but is not available in all hospitals or at all times. We have developed an automated KB counting system that uses machine learning to identify and distinguish fetal and maternal red blood cells (RBCs). In this study, we aimed to evaluate and compare the accuracy, precision, and efficiency of the automated KB counting system with manual KB counting and flow cytometry. METHODS: The ratio of fetal RBCs of the same blood sample was quantified by manual KB counting, automated KB counting, and flow cytometry, respectively. Forty patients were enrolled in this comparison study. RESULTS: Comparing the automated KB counting system with flow cytometry, the mean bias in measuring the ratio of fetal RBCs was 0.0048%, with limits of agreement ranging from -0.22% to 0.23%. Using flow cytometry results as a benchmark, results of automated KB counting were more accurate than those from manual counting, with a lower mean bias and narrower limits of agreement. The precision of automated KB counting was higher than that of manual KB counting (intraclass correlation coefficient 0.996 vs 0.79). The efficiency of automated KB counting was 200 times that of manual counting by the certified technologists. CONCLUSION: Automated KB counting provides accurate and precise FMH quantification results with high efficiency.

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.

Systematic Kleihauer-Betke Test after External Cephalic Version for Breech Presentation: Is It Useful?

The incidence of fetomaternal hemorrhage (FMH) after external cephalic version (ECV) has been poorly reported. In this study, we evaluated the frequency of FMH, diagnosed by positive Kleihauer-Betke test (KBT), after ECV attempt and then evaluate the relevance of its routine use after procedure. A total of 282 women with a term breech presentation and who had ECV attempt were recruited from January 2014 and December 2018. After ECV attempt, women were systematically screened for FMH using KBT. Data on ECV attempt, KBT results, perinatal and neonatal outcomes were collected and compared between women with positive (cases) and negative KBT (controls) after ECV. The success rate of ECV was 22.0% (62/282). Eight women (2.9%) experienced transient fetal heart rate (FHR) abnormalities after ECV. In five (1.8%) women, KBT was positive after ECV. Obstetrical management was modified for two of these five women due to continuous positivity of KBT at day 1 and day 7 controls after ECV attempt. A cesarean section was planned 7 days earlier due to persistent high FMH on day 7 (6 mL fetal blood) in one woman and the labor was induced for persistent high FMH on day 7 (20 mL fetal blood) for another woman. No newborns have signs of fetal anemia at birth and there was no significant difference in neonatal status between two groups. FMH after ECV attempt are rare, and no negative fetal or neonatal outcomes were observed when KBT was positive, even strongly (>5 mL fetal blood). It appears that systematic KBT after attempted ECV is probably not useful.

Reduced fetal movement during pregnancy: Is the Kleihauer-Betke test really useful?

INTRODUCTION: Reduced fetal movement (rFM) is a frequent cause of consultation during the pregnancy and can reveal feto-maternal hemorrhage (FMH) that is sometimes responsible of severe fetal anemia. Our primary objective was to evaluate the contribution of the KBT in case of rFM. Our secondary objective was to compare it with ultrasound examination including peak systolic velocity of the middle cerebral artery (MCA-PSV) to predict neonatal anemia. MATERIALS AND METHODS: We conducted a retrospective study from January 2016 to December 2017 at Armand-Trousseau Hospital in Paris. We analyzed all patients consulting for rFM from 18 to 41 weeks of gestation. We compared the performance of KBT and MCA-PSV to predict neonatal anemia (Hemoglobin at birth under 13.5 g/dL) and severe neonatal anemia (Hb < 10 g/dL). RESULTS: Among the 338 patients, 327 KBT (96.7%) were performed. KBT was found positive in three cases (0.9%). Only one neonate (0.3%) presented with severe anemia requiring a postnatal transfusion. MCA-PSV was performed in 166 cases (49.1%). KBT and MCA-PSV were significantly correlated with neonatal hemoglobin at birth. KBT was better than MCA-PSV to predict neonatal anemia, while MCA-PSV was better than KBT to predict moderate to severe anemia. The KBT and MCA-PSV Doppler had excellent sensitivity and predictive negative values (100%), but they had poor predictive positive values for severe neonatal anemia. CONCLUSION: In case of decreased fetal movement, we suggest performing fetal cerebral Doppler. MCA-PSV could suffice in first approach. KBT may be performed if there is suspicion of fetal anemia in order to confirm FMH.

[Severe neonatal anemia due to fetomaternal hemorrhage: an ilustrative case]. / Anemia neonatal grave secundaria a transfusion feto-materna: a proposito de un caso.

Fetomaternal transfusion (FMT) is defined by the transfer of fetal blood into the maternal circulation. The incidence of massive FMT is estimated to be approximately 0.2-0.9 % of births. Although a number of etiologies have been associated with FMT, most causes remain unidentified and the pregnancy is usually asymptomatic. The most frequent symptom is the decrease in fetal movements (26 %) in relation to severe anemia. Several diagnostic modalities for FMT are described (Kleihauer stain, flow cytometry). We describe a case of a newborn with chronic anemia secondary to FMT who, after treatment with transfusions of red blood cells, presented volume overload and clinical worsening as a complication. In this case, our patient needed exchange transfusion for definitive improvement without disability.

La transfusión feto-materna es el paso de eritrocitos fetales a la circulación materna. Cuando es masiva, tiene una incidencia aproximada del 0,2-0,9 %. Generalmente, se desconoce el agente desencadenante, pero, en ocasiones, se pueden identificar factores de riesgo. En el embarazo, suele ser asintomática; el síntoma más frecuente es la disminución de los movimientos fetales (el 26 %) en relación con la anemia grave. Se diagnostica mediante la detección de hemoglobina fetal en la sangre materna (test de Kleihauer o citometría de flujo). Se presenta a un recién nacido con anemia crónica secundaria a la transfusión fetomaterna, que, después del tratamiento con transfusión de concentrado de hematíes, tuvo como complicación síntomas de sobrecarga de volumen y empeoramiento clínico. Tras la realización de una exanguinotransfusión, evolucionó favorablemente, sin secuelas.

Fetomaternal Bleeding and Neonatal Hematocrit following Cesarean Delivery: Routine versus Transplacental Transection.

Objective To evaluate fetomaternal bleeding following routine cesarean delivery compared with cesarean delivery involving transplacental transection. Study Design A prospective cohort study evaluating cesarean delivery in which the placenta was transected (cases) versus controls (placenta not transected) from January 2016 to April 2018. A maternal Kleihauer-Betke's (KB) test and newborn hematocrit were performed shortly after delivery. Results The rate of a positive KB test was not significantly different between cases ( n = 31) and controls ( n = 61) (19 vs. 14%; odds ratio [OR]: 1.44; 95% confidence interval [CI]: 0.46-4.49; p = 0.74). Median neonatal hematocrits were not different. However, the rate of newborn hematocrits <40% at delivery was higher in cases compared with controls (23 vs. 3%; OR: 8.90; 95% CI: 1.72-45.90; p = 0.005). Conclusion A cesarean requiring transplacental transection to accomplish delivery does not significantly increase the rate of fetomaternal bleeding but is associated with a higher likelihood of newborn hematocrit <40% at delivery.

Prospective quantification of fetomaternal hemorrhage with dilation and evacuation procedures.

OBJECTIVE: To describe fetomaternal hemorrhage (FMH) during second-trimester dilation and evacuation (D&E) to evaluate if Rhesus-immune globulin (RhIG) 100 mcg (used in the United Kingdom) and 300 mcg (used in the United States) provide adequate prophylaxis. STUDY DESIGN: We conducted an exploratory prospective descriptive study of women undergoing D&E between 15 weeks 0 days and 23 weeks 6 days of gestation. Enrolled participants had Kleihauer-Betke testing on specimens obtained before and after D&E. We assessed the main outcome measures of FMH in mL suggesting need for more than 100 mcg and 300 mcg RhIG (FMH of 10 mL and 30 mL fetal whole blood, respectively) and association of postprocedure FMH with demographic characteristics and procedure-related variables. RESULTS: The 300 participants had a mean gestational age of 19 weeks 6 days±2 weeks 2 days. The median preprocedure FMH was 0 mL (range 0-50 mL) with 2 (0.67%) women exceeding 10 mL (19 mL and 50 mL). The median postprocedure FMH was 1 mL (range 0-60 mL). Almost all participants had postprocedure FMH <10 mL (n=295, 98.3%) and <30 mL (n=298, 99.3%). All participants under 18 weeks had FMH <10 mL. We found no demographic or procedure-related factors to be predictive of FMH quantity. CONCLUSIONS: FMH occurring with routine second-trimester D&E procedures is minimal. Adequate prophylaxis with RhIG 100 mcg and 300 mcg occurred in >98% of women and in all cases <18 weeks of gestation. This study is the first step to potentially reducing the dose and costs of RhIG administration with D&E. IMPLICATIONS: This study is a first step in quantifying fetomaternal hemorrhage with routine dilation and evacuation procedures; larger trials are needed, especially to understand why some women have recognizable hemorrhage preprocedure. If dosing requirements are too high with current guidelines, lower doses will result in resource and cost savings.

Usefulness of maternal fetal red blood cell count in rhesus-positive pregnant women.

Background Fetal red blood cells (FRBC) in maternal blood are counted in rhesus-negative women to determine the amount of anti-D immunoglobulin to be administered in the case of a rhesus-positive fetus. In rhesus-positive pregnant women this is done in not always very well-defined indications including trauma, miscarriage, fetal death and diminished fetal movements. The aim of this study is to determine if the detection of FRBC is useful in rhesus-positive pregnant woman. This was done by assessing maternal and fetal characteristics that are more likely to give a positive test. Materials and methods This was a retrospective cohort study. Results A total of 169 FRBC tests were performed in 161 rhesus-positive pregnant women. FRBC were found in 45 (26.6%) of the women. Three patients experienced a miscarriage although their FRBC tests were negative (p = 0.295). Of the seven patients who experienced unexpected stillbirths, three tested positive. The deaths were not less likely to occur if the results had been negative (p = 0.631). There was a statistically significant difference between the different types of trauma indications (p = 0.025): the test was more likely positive if there had been a fall on the ground or staircase or blunt trauma (p = 0.041, 0.026 and 0.018, respectively). FRBC were not more frequently present in the absence of fetal movements (n = 16, p = 0.693). Conclusion FRBC in maternal blood were more likely positive in the case of a fall on the ground, or from a staircase. However, a positive test does not necessarily imply fetal pathology and, therefore, does not contribute to clinical management.

[Trauma and pregnancy: Is the Kleihauer-Betke test really useful?] / Traumatisme et grossesse : le test de Kleihauer est-il vraiment utile ?

OBJECTIVE: To evaluate the pertinence of Kleihauer-Betke (KB) test, in case of abdominal trauma during pregnancy in forecast of fetal outcomes, according to trauma severity. METHODS: A single-center retrospective study conducted between January 2014 and April 2016 in a maternity type III and a trauma center, which included the pregnant women admitted for abdominal trauma. The trauma's severity was assessed using the guidelines of the Society of Obstetricians and Gynaecologists of Canada. The impact of a positive KB test, defined as>0.1%, was analyzed. Adverse outcome was defined as one or more of the following complications: intrauterine fetal death, placental abruption, pre-term birth<37 weeks of gestation, and fetal or neonatal anemia. RESULTS: During the study period, 265 pregnancies involved into an abdominal trauma were included: 69% with a minor trauma and 31% with a severe trauma. Of all patients, 5.6% presented a positive KB test, among then 15.4% had an adverse outcome. There was no significant difference in the rate of adverse outcomes in the positive KB group and the KB negative group either in the overall population (P=0.16), in the minor trauma population (P=1) or in the major trauma population (P=0.14). The predictive positive values were respectively in the global population, in the minor trauma group and in the severe trauma group 15.4%, 0% and 25%. CONCLUSIONS: The KB test does not seem to be useful in case of trauma during pregnancy to define adverse outcome.

Placental findings in feto-maternal hemorrhage in livebirth and stillbirth.

Feto-maternal hemorrhage (FMH) is not an uncommon event during pregnancy with important clinical implications for both maternal and fetal outcomes. The diagnosis is often made using Kleihauer-Betke (KB) test. As FMH occurs transplacentally, examination of the placenta may contribute to the diagnosis of FMH. This retrospective case-control study aims to examine the placental features associated FMH in patients with known positive KB test results. When compared with KB negative placentas (n=88), KB positive placentas (n=49) had significantly higher incidence of pallor (6/49 vs 0/88, p=0.0017), IVT (11/49 vs. 5/88, p=0.0032) and nRBCs (12/49 vs. 4/88, p=0.0008). Autopsy cases with fetal or neonatal death due to FMH, (n=13) compared to a cohort of 162 placentas associated with other, non-FMH causes of death also had significantly higher frequency of pallor (5/13 vs 0/162, p<0.0001), IVT (6/13 vs 24/162, p=0.011) and nRBCs (11/13 vs 67/162, p=0.003). Pallor and nRBC were also associated with higher volume of FMH. Placental parenchymal pallor, intervillous thrombi and presence of nRBCs are significantly associated with documented FMH in both normal pregnancies and pregnancies associated with fetal or neonatal death. The presence of these findings, especially in combination, may suggest the need for maternal KB testing to rule out FMH and neonatal monitoring and/or intervention.