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.

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.

Blood Group Antigen Matching Influence on Gestational Outcomes (AMIGO) study.

BACKGROUND: Red blood cell (RBC) antigen matching policies to prevent alloimmunization in females of childbearing potential (FCP) vary between centers. To inform transfusion centers responsible for making decisions about matching policies for FCPs, the causal stimulus of the antibodies implicated in severe hemolytic disease of the fetus and newborn (HDFN) must be determined. STUDY DESIGN AND METHODS: We conducted a multinational retrospective study of women with offspring affected by severe HDFN requiring neonatal exchange transfusion and/or intrauterine transfusion. Mothers treated at centers that provide extended antigen-negative RBCs (MATCH, five centers) and those that do not (NoMATCH, nine centers) were compared. RESULTS: A total of 293 mothers had at least one affected pregnancy: 179 at MATCH centers and 114 at NoMATCH centers. Most alloimmunization (83%) was attributed to previous pregnancy: 3% to transfusion (two cases at MATCH, six at NoMATCH centers) and 14% undetermined (both antecedent transfusion and pregnancy). Only 50 mothers had received transfusions; 13 had HDFN due to anti-K at MATCH and four at NoMATCH centers. Most (12/13, 92%) of the anti-K HDFN cases at MATCH centers had K+ paternal antigen status. Mothers at the MATCH centers do not appear to be protected from HDFN due to K, C, c, and E antibodies, although the low number of FCPs who received transfusions precluded drawing firm conclusions. CONCLUSION: The causal stimulus of antibodies that cause HDFN is predominantly from previous pregnancy. Although extended RBC matching for FCPs may impart some protection from allosensitization, we were unable to show a positive effect, possibly because matching policies are not uniform and there was a small number of mothers who previously received transfusions.

Red cell alloimmunization in RhD positive pregnant women and neonatal outcome.

The frequency of red blood cell (RBC) alloimmunization in RhD positive pregnant women is not known in our population. We planned to determine its frequency and correlation with neonatal outcome. We included 1000 RhD positive pregnant women: 500 had 'normal pregnancy' (Group I) and another 500 had 'high risk pregnancy' (Group II). ABO and extended Rh phenotyping were done by tube technique, antibody screening and identification by gel technique. For alloimmunized women, the paternal and neonatal ABO and extended Rh typing were done. Neonatal direct antiglobulin test (DAT) was also done and their clinical outcome observed. The frequency of RBC alloimmunization was 0.7% (7/1000) and all these women were from group II (p = 0.015). The alloantibodies were anti-E (85.7%), anti-c (71.4%), anti-Cw (14.3%) and anti-S (14.3%). Also, 6 women had history of transfusion (p < 0.01). Of the 7 neonates born to alloimmunized mothers, 4 (57.14%) had a positive DAT. The mean duration of phototherapy was higher in the DAT positive neonates (p < 0.01) and 2 (50%) required exchange transfusion. Thus, the frequency of alloimmunization was 0.7% in RhD positive pregnant women. High risk pregnancies and antenatal patients having a history of blood transfusion should be considered for regular antibody screening.

Occult fetomaternal hemorrhage in women with pathological placenta with respect to permeability.

AIM: Women with pre-eclampsia (PE), placenta previa (PP), placental abruption (PA), and placental mesenchymal dysplasia (PMD) have been described as having placental permeability dysfunction. This study was performed to determine whether occult fetomaternal hemorrhage (FMH) is common in women with such complications and in women with non-reassuring fetal status. METHODS: Forty-one antenatal and 39 postnatal blood samples were obtained from 46 women, including 11 with placental permeability dysfunction (5, 3, 2, and 1 with PE, PP, PA, and PMD, respectively) and 35 controls without such complications. To estimate the amount of fetal red blood cells, flow cytometry was performed using the fetal cell count system with two antibodies against fetal hemoglobin and carbonic anhydrase and the ß-γ system with two monoclonal antibodies against hemoglobin ß-chain and hemoglobin γ-chain. A diagnosis of FMH was made when the fraction size of the isolated cell population on scatter plots expressing fetal hemoglobin alone or hemoglobin γ-chain alone accounted for ≥0.02% of the total cell population on scatter plots. RESULTS: FMH was identified in five women, including one each with PE, PA, PP, PMD, and no complications. Thus, the prevalence rate of FMH was significantly higher in women with complications than in controls (36% [4/11] vs 2.9% [1/35], respectively, P =  0.009). The FMH occurrence rate did not differ between women with and without non-reassuring fetal status (7.7% [1/13] vs 12% [4/33], respectively, P =  1.000). CONCLUSION: The risk of fetal red blood cells trafficking into the maternal circulation may be increased in women complicated with PE, PA, PP, and PMD.

Risk of maternal alloimmunization in Southern Pakistan - a study in a cohort of 1000 pregnant women.

BACKGROUND: Haemolytic disease of the fetus and the newborn [HDFN] is caused by incompatibility of maternal and fetal erythrocytes. Red blood cell alloimmunization is a well-known cause of HDFN. Due to heterogeneity of populations, the spectrum of alloimmunization varies around the world. This study aimed to determine the frequency of alloimmunization in pregnant women and to determine the risk of HDFN in our population. STUDY DESIGN AND METHODS: This was a descriptive study conducted at Aga Khan University Hospital Karachi. Blood type and red cell antibody screening was determined on every pregnant woman at her first antenatal visit. Red cell antibody identification was performed on positive screening results. RESULTS: A total of 1000 pregnant females including 633 (63.3%) multigravida were studied. Blood type B was predominant (n = 374 or 37.4%) and D negative was observed in 136 women (13.6%). No red cell antibody was detected in 982 females (98.2%). 20 red cell antibodies were detected in 18 women (1.8%). The incidence of non-anti-D was 16/1000 [1.6%] in all pregnant females. The non-anti-D alloantibodies included anti-M (n = 3; 15%), anti-Lewis(a) (n = 3; 15%), anti C ( n = 1; 5%), anti-E (n = 1; 5%), anti-e (n = 1; 5%), anti-Lewis(b) (n = 1; 5%) and nonspecific antibodies (n = 6; 30%). The incidence of anti-D was 4/136 or 2.9% in D negative blood type. After excluding prior sensitization due to blood transfusions, risk remained was 2.2%. Antibodies of clinical significance were identified in 9 (0.9%) females. CONCLUSIONS: In our cohort, frequency of red cell alloimmunization during pregnancy was 1. 8% out of which 0.9% were clinically significant antibodies posing a risk for HDFN. Despite prenatal and post natal prophylaxis, risk of sensitization with D antigen in D negative women was high at 2.2%. We recommend that all pregnant women should be screened for irregular antibodies irrespective of the rhesus type.

A correlation between severe haemolytic disease of the fetus and newborn and maternal ABO blood group.

OBJECTIVE: To analyse anti-D quantification levels and frequency of intrauterine transfusion (IUT), per maternal ABO blood group. BACKGROUND: Maternally derived red cell allo-antibodies can target fetal red cell antigens in utero leading to haemolytic disease and fetal anaemia. When a clinically significant allo-antibody is formed the priority is ascertaining the risk to the fetus and maternal ABO blood groups are not considered relevant. MATERIALS AND METHODS: This was a 10-year retrospective, observational study carried out on women referred for anti-D quantification (n = 1106), and women whose fetuses required an IUT to treat fetal anaemia (n = 62) due to anti-D, in the Republic of Ireland. RESULTS: Relative to the overall incidence of RhD allo-immunisation by blood group, women of blood group A were more likely to require IUT compared with those who were blood group O (P = 0.002). CONCLUSION: It is known that ABO feto-maternal compatibility can influence the incidence and level of red cell allo-antibodies in pregnancy; however, it does not account for the significantly high rate of severe haemolytic disease requiring IUT seen in blood group A women.

Alloimmunisation during pregnancy in Greece: need for nationwide HDFN prevention programme.

AIM/OBJECTIVES: To access the incidence and specificity of maternal red blood cells alloimmunisation and its relevant clinical impact in Greece. BACKGROUND: The rate of alloimmunisation in pregnant women in Greece is unknown. MATERIALS/METHODS: We performed a 4-year study in two tertiary hospitals in Greece. Demographics, transfusion and obstetric history were analysed. Maternal alloimmunisation was detected with indirect anti-globulin test. RESULTS: We investigated 4368 pregnant women. Of which 3292 (75·37%) were Greek and 1076 (24·63%) were migrants. In 39 alloimmunised women, 41 alloantibodies were detected (0·89%). The incidence of alloimmunisation was 0·66% (22/3292) in Greeks and 1·76% (17/1076) in migrants (P = 0·01). Anti-D was the most frequent alloantibody (0·18%). Anti-D was more frequent in migrants; 5·76% compared to 0·56% in Greek RhD negative women (P = 0·002). Other antibody specificities in declining frequency rank were anti-K, anti-E, anti-Lea, anti-M, anti-c, anti-Ce, anti-Jka, anti-Jkb and anti-C. Primiparae vs para >2 and past history of blood transfusion were significantly associated with alloimmunisation during pregnancy (P = 0·0088, P < 0·0001, respectively). CONCLUSIONS: Our results depict differences in the delivery of health care between migrants and Greek women, as well as the heterogeneity in practices for the prevention of haemolytic disease of foetus and newborn in Greece and highlight the need for the implementation of nationwide guidelines.

Fetomaternal hemorrhage in normal vaginal delivery and in delivery by cesarean section.

BACKGROUND: The objective was to determine the incidence and volume of fetomaternal hemorrhage (FMH) in normal vaginal delivery and in delivery by cesarean section. Determination of these variables would enable optimalization of guidelines for D alloimmunization prophylaxis. STUDY DESIGN AND METHODS: In a prospective cohort study, a total of 3457 examinations were performed, 2413 after normal vaginal delivery and 1044 after cesarean delivery. FMH was assessed by flow cytometry. (FMH is fetal red blood cell [RBC] volume; fetal blood volume is double [expected fetal hematocrit is 50%].) RESULTS: The fetal RBC volume diagnosed in maternal circulation after delivery ranged from insignificant FMH of not more than 0.1 mL to excessive FMH of 65.9 mL (median, 0.7; mean, 0.78; SD, 1.48). FMH of more than 2.5 mL (immunoglobulin [Ig] G anti-D insufficient dose 50 µg) was observed in 1.4% (49/3457) and excessive volumes of FMH of more than 5 mL (insufficient dose, 100 µg) in 0.29% (10/3457). Delivery by cesarean section presented a higher risk of incidence of FMH of more than 2.5 mL (odds ratio, 2.2; p = 0.004) when compared with normal vaginal delivery. It did not, however, present a significant risk factor for the incidence of excessive volumes of FMH of more than 5 mL. CONCLUSION: During normal vaginal delivery as well as during delivery by cesarean section, FMH of less than 5 mL occurs in the great majority of cases, and thus for the prevention of D alloimmunization, an IgG anti-D dose of 100 µg should be sufficient. Contrarily, only rarely does greater FMH occur and delivery by cesarean section does not present a risk factor.

Fetomaternal hemorrhage in the second trimester.

AIMS: To investigate fetomaternal hemorrhage (FMH) rate and quantity in the second trimester of pregnancies with fetal anomalies and to assess the impact of invasive prenatal and termination procedures. METHODS: Blood samples from women before termination of pregnancy were collected and analyzed by dual-color flow cytometry. Various clinical parameters were studied for their association with FMH. RESULTS: In total, 67 women were recruited; pre- and post-termination pairs were collected for 31 women. HbF cells were present in 91.0% of specimens, in 29.9% the transfused blood volume was ≥4.2 mL. FMH ≥30 mL was found in 3.0%, and chronic FMH, defined as FMH ≥40% of fetoplacental blood volume in 7.5%. At the limit of quantification (0.1%) none of the clinical parameters was associated with the presence of HbF cells, nor was there a difference in HbF cell concentrations between pre- and post-termination blood samples. CONCLUSIONS: Compared to normal term pregnancy, transfer of fetal red blood cells into the maternal circulation is increased in second-trimester pregnancies with fetal anomalies. FMH is not associated with invasive procedures or surgery performed in the context of termination. We hypothesize that the abnormal pregnancy itself, by means of an abnormal uteroplacental interface, is causing the increased transfer.

Fetomaternal hemorrhage in women undergoing elective cesarean section.

OBJECTIVE: To investigate the degree of fetomaternal hemorrhage (FMH) caused by elective cesarean section. DESIGN: Descriptive study. SETTINGS: University Hospitals in Copenhagen, Denmark. POPULATION: Women scheduled for elective cesarean section, in the period September 2007 to January 2009, at the Department of Gynecology and Obstetrics, Hvidovre Hospital, University of Copenhagen, Denmark. METHODS: Two maternal blood samples were taken, the first before cesarean section and the second immediately after. Both samples were analyzed at the Blood Bank, Rigshospitalet, Copenhagen, for the presence of fetal red blood cells (fRBCs) using flow cytometry. FMH associated with cesarean section was defined as the difference between the volumes of fRBCs in the two samples. MAIN OUTCOME MEASURES: The frequency and volume of FMH caused by elective cesarean section. RESULTS: 207 women were included in the study. FMH was detected in 38 cases (18.4%). Of these, 22 women (10.6%) had FMH of less than 1 ml fRBCs, 13 women (6.3%) had FMH between 1 and 4 ml fRBCs, and three women (1.4%) had FMH above 4 ml fRBCs. CONCLUSIONS: We found no evidence for recommending general screening for FMH in connection with elective cesarean section, provided guidelines such as the current Danish guidelines for Rhesus prophylaxis are followed.

Maternal red blood cell alloimmunisation in south western Uganda.

AIMS/OBJECTIVES: To identify the frequency and nature of maternal red blood cell (RBC) alloimmunisation in Uganda and to determine the prevalence of RhD negativity and the rate of RBC alloimmunisation in Ugandan pregnant women. BACKGROUND: Haemolytic disease of the foetus and newborn (HDFN) results from maternal alloimmunisation following exposure to allogeneic RBCs during pregnancy or blood transfusion. The prevalence of maternal RBC alloimmunisation in Ugandans is not known. MATERIALS AND METHODS: Pregnant women at Mbarara Hospital, South Western Uganda, were investigated in a cross-sectional study. Demographics, transfusion and obstetric histories were recorded. Maternal RBC alloimmunisation was demonstrated using immunohaematological techniques. RESULTS: A total of 2001 pregnant women were recruited; 3.6% of them being RhD negative. Forty-five women (2.2%; 95% CI: 1.6-2.9) were found to be alloimmunised to RBC antigens. There were 38 RBC alloantibodies of known specificity including anti-S, 12; anti-M, 11; anti-Le(a) , 6; anti-D, 4 and 1 each of anti-K, anti-Fy(b) , anti-Jk(a) , anti-Lu(a) and anti-Kp(a) . In two women (4.4%), there were antibody combinations (anti-M+S and anti-K+Kp(a) ). Obstetric history, gestational age and previous immunising events were not significantly associated with the rate of alloimmunisation. CONCLUSIONS: This study revealed a maternal RBC alloimmunisation rate of 2.2% which was comparable with findings from a Zimbabwean study where the prevalence was 1.7%. Given the 6·0% prevalence of anti-D among RhD-negative women in our study and the high immunogenicity of the D antigen, programmes for preventing anti-D alloimmunisation and HDFN in Uganda should be considered seriously.

[Fetomaternal hemorrhage: practitioner's point of view]. / Hémorragie foetomaternelle : le point de vue du clinicien.

Fetomaternal hemorrhage is known to have a wide spectrum of clinical presentations. This large variability probably explains why there are still neither consensual classification nor management recommendations. Nevertheless, fetomaternal hemorrhage is a serious condition, which may cause life-threatening fetal anemia. Fetal tolerance mainly depends on the quantity of fetal blood loss as well as the rate at which it occurs. Decrease in perceived fetal movements represents the main clinical sign of fetomaternal hemorrhage and justify use of diagnostic tests such as the Kleihauer-Betke test. Large fetomaternal hemorrhages can also induce fetal hydrops and stillbirth. In this review, we emphasize the clinical and biological features of fetomaternal hemorrhages and we highlight the circumstances associated with false-negative and false-positive results of the Kleihauer-Betke test. We also propose an original algorithm for the management of fetomaternal hemorrhages.

Fetal-maternal microchimerism in normal parous females and parous female cancer patients.

OBJECTIVE: The prevalence of male microchimerism (MC) in parous females, nonparous females, and parous female cancer patients was examined. MATERIALS AND METHODS: DNA extracted from peripheral blood leukocytes and male Y-chromosomal DNA was amplified using a sensitive two-stage polymerase chain reaction technique. Controls prepared by mixing human male and female cell lines demonstrated the sensitivity of the technique to be in the range of 1 male cell per 1 million female cells. RESULTS: Findings of this study showed that the percentage of MC-positive females was highly dependent on the amount of DNA analyzed; 57% of normal parous females who bore at least one son were found to have male cells in their blood when 25 mug DNA or more from the samples was analyzed. This frequency is much higher than previous reports indicating a prevalence of 33% for normal parous females. Analysis of samples obtained from 200 parous female cancer patients revealed an incidence of 34% MC(+); 7.4% of normal nonparous female controls had evidence of MC. CONCLUSION: The long-term persistence of male cells in the maternal circulation could indicate maternal immune tolerance of paternally inherited fetal antigens. This maternal tolerance might be exploited in female patients with malignant disease to deliver immune cellular therapy from their sons.

Fetomaternal hemorrhage among pregnant women in Accra, Ghana.

OBJECTIVE: To determine the occurrence of and risk factors for fetomaternal hemorrhage (FMH) among pregnant women at Korle Bu Teaching Hospital in Accra, Ghana. METHODS: A prospective study of FMH among pregnant women without hemoglobinopathies in the second trimester attending prenatal care between October 2015 and May 2016 performed using the Kleihauer-Betke test. Volume of FMH was estimated; ABO and Rh blood groups of participants were determined. A data extraction form and structured questionnaire were used to collect demographic and clinical information, and data on risk factors. RESULTS: Of 151 participants, 32 (21.2%) had FMH. Almost 18% (n=27) had FMH at baseline (16-24 weeks), 10% (10/100) at 28-32 weeks, and 11.1% (11/99) at 34-37 weeks of pregnancy. Volume of FMH was less than 30 mL in 30 (19.9%) women, whereas it was greater than 30 mL in 2 (1.3%) women. No identifiable patient-specific factors were associated with occurrence of FMH. CONCLUSION: FMH is common among pregnant women in Ghana and can occur as early as 16 weeks, without identifiable risk factors. RhD negative women who may be pregnant with RhD positive fetuses should be screened early in pregnancy, not only at delivery, for occurrence of FMH.

Feto - maternal haemorrhage in parturients: Incidence and its determinants.

This prospective study of parturients at a tertiary health institution in south-western Nigeria aims to identify the incidence, severity and obstetric factors predisposing to feto - maternal haemorrhage (FMH) in our population. The exclusion criteria were haemoglobinopathy and patient's refusal of consent to participate in the study. The prepared slide was processed as in the acid elution test described by Kleihauer - Betke. The FMH was calculated using Mollison formula (Mollison 1972). Baseline data included maternal biodata, blood group, RhD and haemoglobin electrophoresis, route/mode of delivery, duration of labour, obstetric interventions, fetal blood group and birth weight. Data generated were analysed with Statistical Package for Social Scientists (SPSS) version 11 software. Frequency tables, cross-tabulations and correlations were performed. Pearson's correlation was applied to continuous variables, while Spearman's correlation was utilised for discrete variables. Level of statistical significance was set at p < 0.05. A total of 163 parturients were studied, of which eight were multifetal gestations. There were no significant differences in maternal age, parity, estimated gestational age at delivery and birth weight, in both groups of parturients with and without FMH. A total of 17 parturients (10.43%), four of which were multifetal gestations (2.45%), had demonstrable FMH. Large FMH (>15 ml fetal cells) were noted in 10 (6.14%) parturients, of which, four were RhD-negative mothers. A total of 9.8% and 11.5% parturients in the vaginal and caesarean delivery groups, respectively, had significant FMH (p = 0.736). Incidence of large FMH was similar with each of the routes of delivery. Antepartum complications of pregnancy, delivery manoeuvres and episiotomy were not significant determinants of FMH. Multiple gestations, fetal birth weight and complications in labour were significantly associated with risk of FMH. Risk-based approach to management, in RhD negative pregnant women, might lead to under-treatment, with attendant increased incidence of isoimmunisation. At least in all RhD-negative women, the cord blood should be tested to determine the baby's blood group and if RhD-positive, Kleihauer - Betke test should be done to determine the degree of FMH and anti-D immunoglobulin dose administered appropriately. Further studies are necessary to establish the determinants/risk factors for FMH.

Placental drainage of fetal blood at cesarean delivery and feto maternal transfusion: a randomized controlled trial.

OBJECTIVE: To assess the efficacy of placental drainage of fetal blood at the time of cesarean delivery on the incidence of feto-maternal transfusion. METHODS: This randomized trial includes 86 gravid women who underwent cesarean delivery. Forty-four women were assigned to the placental drainage group and 42 to the no-drainage group. Placental drainage was accomplished by cutting and milking the umbilical cord until no further blood flow occurred. All placentas were spontaneously expelled. The primary outcome variable, as assessed by preoperative and postoperative Kleihauer-Betke tests, was the amount of fetal blood (greater than or equal to 0.5 mL) in the maternal circulation. RESULTS: The group having placental drainage of fetal blood before placental delivery showed a significantly lower incidence (3 of 44, 6.8%) of feto-maternal transfusion (P=.003) as compared with the undrained group (14 of 42, 33%; relative risk 0.20, 95% confidence interval 0.065-0.65; number needed to treat=4). CONCLUSION: Placental drainage of fetal blood before spontaneous placental delivery at the time of cesarean delivery significantly reduces the incidence of feto-maternal transfusion. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00470899 LEVEL OF EVIDENCE: I.

Role of Kleihauer test in Rhesus negative pregnancy.

OBJECTIVE: To determine the role of Kleihauer test in estimating fetomaternal haemorrhage and dose of injection anti-D. DESIGN: Analytical study. PLACE AND DURATION OF STUDY: MCH Center, Unit-II, PIMS, Islamabad, from February to December 2004. PATIENTS AND METHODS: A hundred Rhesus negative pregnant women delivered after 28 weeks gestation during the study period were studied. The main outcome measures were Kleihauer test estimation of fetomaternal haemorrhage and association of significant fetomaternal haemorrhage with antepartum haemorrhage (APH), amniocentesis, twin delivery, intrauterine death (IUD), external cephalic version (ECV), manual removal of placenta and cesarean section. RESULTS: Among the hundred women, 28 were primigravidae while 72 were multigravidae. Mean gestational age at delivery was 38.4+/-1.6 weeks. In 24% Rhesus-D negative subjects, potential sensitizing events occurred antenatally. In 11% of these, events occurred before 24 weeks of gestation. Two percent underwent ECV, 10 % had blunt abdominal trauma in third trimester while one patient had APH. Sixty five women had vaginal delivery and cesarean section was performed in 35. Outcome was alive baby in all cases except one intrauterine fetal demise (IUD). Four patients had placenta removed manually. Mean amount of fetomaternal haemorrhage was 2.7+/-1.01 ml (1.2-5.2 ml). The mean anti-D dose required was 67.3+/-25.3 microg. Twenty six women did not need anti-D as they had Rhesus negative infants. CONCLUSION: In this series routine postnatal Rhesus prophylaxis with 300 microg anti-D immunoglobulin covered all the feto-maternal haemorrhage. Therefore, Kleihauer test with added burden of cost is not indicated as a routine to rhesus negative women.

Demographic and Behavioral Predictors of Severe Fetomaternal Hemorrhage: A Case-Control Study.

BACKGROUND: Fetomaternal hemorrhage (FMH) signifies failure of the placental barrier with whole blood transfer. Fetal anemia following FMH is associated with significant morbidity and mortality. If FMH is identified early, fetal anemia can be treated to minimize adverse outcomes. Risk factors for FMH are not known, limiting efforts to provide targeted screening for FMH. OBJECTIVE: To identify maternal and/or pregnancy characteristics associated with FMH that are recognizable prior to fetal morbidity. METHODS: This is the first published case-control study of FMH. Cases were identified from a prospectively maintained database of all hospital births between 1988 and 2010. Each case was matched to 4 controls by date and time of birth, allowing for assessment of a wide range of clinical and demographic data. Logistic regression modeling was used to assess the association between demographic and clinical characteristics and the diagnosis of FMH. RESULTS: A total of 23 mother-baby pairs impacted by FMH and 92 matched controls were evaluated. Compared to controls, case mothers were more likely to have private insurance and to work outside the home and at night during pregnancy. Cases were more likely to be delivered preterm, but preterm labor was not more common among cases. There was no difference in race/ethnicity of cases compared to controls. CONCLUSIONS: Severe FMH is associated with significant morbidity and mortality of the affected neonate. Women with FMH were more likely to work outside the home during pregnancy than women with normal pregnancies. This finding has implications for third-trimester screening of pregnant women who work in strenuous fields.

A pilot prospective study of fetomaternal hemorrhage identified by anemia in asymptomatic neonates.

OBJECTIVE: Fetomaternal hemorrhage (FMH) is a poorly understood condition in which fetal erythrocytes transfer to the maternal circulation via a faulty placental barrier. Little is known about the true incidence, epidemiology or pathophysiology of FMH in the general pregnant population as existing studies are based on retrospective cohorts and manifest diagnosis and selection bias. The objective of this study was to evaluate the practicability of a prospective study of FMH in the general population based on antepartum maternal blood testing and neonatal anemia. STUDY DESIGN: Prospective cohort study. RESULT: Nineteen pregnant women were enrolled prior to the term delivery of 20 well infants. Five neonates were unexpectedly anemic on first postnatal testing. Antenatal maternal blood samples associated with two of the five anemic newborns had positive Kleihauer-Betke testing while no newborn with a normal postnatal blood count had an associated abnormal Kleihauer-Betke test. CONCLUSION: Clinically significant FMH may be more common than previously thought. Prospective epidemiological study of FMH is feasible.