Routine maternal ABO/Rhesus D blood typing can alert of massive foetomaternal haemorrhage.

BACKGROUND AND OBJECTIVES: Spontaneous massive foetomaternal haemorrhage (SM-FMH) is a rare yet critical condition that poses substantial risk to foetal health and survival. Existing data indicate that many cases may be undiagnosed. The current study aimed to investigate and validate the utility of identifying mixed field red blood cell (RBC) agglutination during maternal blood typing as a diagnostic aid for SM-FMH. MATERIALS AND METHODS: Retrospective analysis of medical records from neonates born at our tertiary, university-affiliated medical centre between 2016 and 2023 was performed. Diagnosis of SM-FMH was based on neonates born with severe anaemia (haematocrit [HCT] <15%) within the first 24 h post-delivery with positive maternal Kleihauer-Betke (KB) test. Maternal ABO/Rhesus D (RhD) blood typing results were scrutinized with the primary objective of assessing the ability to identify dual RBC populations in cases clinically diagnosed with SM-FMH. RESULTS: Among 29,192 neonates studied, a mere 0.02% (5 cases) exhibited severe SM-FMH. Notably, a mixed field RBC agglutination was discerned in 80% (4/5) of these cases. CONCLUSION: This study underscores the significance of detecting mixed field RBC agglutination during antepartum maternal ABO/RhD blood typing as a potential indicator for SM-FMH. Increased awareness among blood bank technology specialists and obstetricians regarding these laboratory findings could prove instrumental in saving foetal lives.

Evaluating emergency-release blood transfusion of newborn infants at the Intermountain Healthcare hospitals.

BACKGROUND: An emergency-release blood transfusion (ERBT) protocol (uncrossmatched type O-negative red blood cells, AB plasma, AB platelets) is critical for neonatology practice. However, few reports of emergency transfusions are available. We conducted an ERBT quality improvement project as a basis for progress. STUDY DESIGN AND METHODS: For each ERBT in the past 8 years, we logged indications, products, locations and timing of the transfusions, and outcomes. RESULTS: One hundred forty-nine ERBTs were administered; 42% involved a single blood product, and 58% involved two or more. The incidence was 6.25 ERBT per 10,000 live births, with a higher rate (9.52 ERBT/10,000) in hospitals with a Level 3 neonatal intensive care unit (NICU) (p < 0.001). Seventy percent of ERBTs were administered in a NICU and 30% in a delivery room, operating room, or emergency department. Indications were abruption/previa (32.2%), congenital anemia (i.e., fetomaternal hemorrhage; 15.4%), umbilical cord accident (i.e., velamentous insertion; 15.0%), and bleeding/coagulopathy (12.8%). Fifty-eight percent of those with hemorrhage before birth did not have a hemoglobin value reported on the umbilical cord gas; thus, anemia was not recognized initially. None of the 149 ERBTs were administered using a blood warmer. The mortality rate of recipients was 35%. CONCLUSION: Based on our findings, we recommend including a hemoglobin value with every cord blood gas after emergency delivery to rapidly identify fetal anemia. We also discuss two potential improvements for future testing: 1) the use of a warming device for massive transfusion of neonates and 2) the use of low-titer group O cold-stored whole blood for massive hemorrhage in neonates.

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.

Does Maternal Body Mass Index Affect the Quantity of Circulating Fetal Cells Available to Use for Cell-Based Noninvasive Prenatal Test in High-Risk Pregnancies?

We present the first study that investigates the effect of maternal body mass index (BMI) on the quantity of circulating fetal cells available to use in cell-based noninvasive prenatal test (cbNIPT). cbNIPT has been proposed as a superior alternative to noninvasive prenatal test from cell-free fetal DNA. Kølvraa et al. [Prenat Diagn. 2016 Dec; 36(12): 1127-34] established that cbNIPT can be performed on as few as one fetal cell, and Vestergaard et al. [Prenat Diagn. 2017 Nov; 37(11): 1120-4] demonstrated that these fetal trophoblast cells could be used successfully in cbNIPT to detect chromosomal and sub-chromosomal abnormalities. This study on 91 pregnant women with high-risk pregnancies suggests that cbNIPT should not be hampered by an increased BMI because every pregnancy, irrespective of the BMI, has rendered fetal cells for downstream genetic analysis. The mean number of fetal cells per sample was 12.6, with a range of 1-43 cells in one sample. ANOVA showed that increasing maternal BMI tends to decrease the number of fetal cells, but not significantly.

Clinical input of anti-D quantitation by continuous-flow analysis on autoanalyzer in the management of high-titer anti-D maternal alloimmunization.

BACKGROUND: In addition to titration by indirect antiglobulin test most widely used, anti-D quantitation by continuous-flow analysis (CFA) may be performed to assess severity of maternal immunization. Only five studies have reported its added value in the management of pregnancies complicated by anti-D immunization. STUDY DESIGN AND METHODS: A retrospective study of 74 severe anti-D-immunized pregnancies was conducted from January 1, 2013, to December 31, 2014, in the Trousseau Hospital in Paris (France). Concentration of maternal anti-D was measured by titration and by CFA two-stages method (2SM; total amount of anti-D) and one-stage method (1SM; high-affinity IgG1 anti-D). These biologic data were analyzed according to the severity of the hemolytic disease of the fetus and the newborn. RESULTS: The value of 5 IU anti-D/mL in maternal serum is validated as a threshold to trigger ultrasonographic and Doppler fetal close follow-up. A high 1SM/2SM ratio was associated with a higher risk of intrauterine transfusion (IUT). For pregnancies requiring IUT and without increasing titer, maternal 1SM anti-D concentration tends to correlate with the precocity of fetal anemia. In the "without-IUT" group 1SM and 2SM anti-D concentrations correlate significantly with cord bilirubin levels of the newborn at birth. CONCLUSION: Altogether our results underline the importance of anti-D quantitation by CFA to optimize the management of anti-D-alloimmunized pregnancies.

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.

Characterisation of maternal human leukocyte antigen class I antibodies in suspected foetal and neonatal alloimmune thrombocytopenia.

OBJECTIVES: To investigate the specificities and level of HLA class I antibodies in selected cases referred for suspected foetal and neonatal alloimmune thrombocytopenia (FNAIT). BACKGROUND: FNAIT occurs in 1 : 1-2000 live births, whereas maternal immunisation against human leukocyte antigen (HLA) class I is common. Whether HLA class I antibodies alone can cause FNAIT is debatable. MATERIAL AND METHODS: A total of 260 patient samples were referred between 2007 and 2012. Referrals with maternal HLA class I antibodies and no other cause for the neonatal thrombocytopenia were included for analysis (cases, n = 23). HPA-1a negative mothers were excluded. Control groups were screened positive mothers of healthy neonates (controls, n = 33) and female blood donors (blood donors, n = 19). LABScreen single antigen HLA class I beads was used for antibody analysis. Clinical records were reviewed for cases. RESULTS: All groups had broad antibody reactivity. Cases had more antibodies with high SFI levels compared with the controls (SFI>9999; medians 26, 6 and 0; P < 0·05) and higher overall median HLA-ABC and HLA-B SFI (P < 0·05). Many of the antibodies were reactive with rare alleles. When reviewing the clinical records, several of the cases had other contributing factors to the thrombocytopenia. There was no correlation between foetal platelet count and antibody levels. CONCLUSION: Mothers of thrombocytopenic neonates had higher levels of HLA class I antibodies compared with control groups of women with healthy children and female blood donors. However, clinical outcome and antibody response correlated poorly in the heterogeneous case group, indicating a multifactorial cause to the thrombocytopenia in the majority of cases.

A descriptive single-centre experience of the management and outcome of maternal alloantibodies in pregnancy.

BACKGROUND: Haemolytic disease of the fetus and newborn (HDFN) occurs when maternal IgG alloantibodies to fetal red blood cell antigens cross the placenta, causing haemolysis in the fetus and/or neonate. After delivery, the main concern is hyperbilirubinaemia, which can cause neurological damage. OBJECTIVES: To summarise our current management and outcome data to inform health-care professionals counselling women whose pregnancies are at risk of HDFN and to compare these data with relevant studies. METHODS: This is a retrospective descriptive study of all high-risk pregnancies at risk of HDFN at Guy's and St. Thomas' NHS Foundation Trust (GSTFT) Maternity Unit over a 7-year period. We defined high-risk pregnancies as those in whom anti-D, anti-c, anti-K or high (>32 or doubling strength) titres of all other antibodies were identified. RESULTS: A total of 130 pregnancies in 112 women were followed up. A single alloantibody was found in 93 pregnancies (71.5%) and multiple alloantibodies in 37 pregnancies (28.5%). Anti-D was most commonly encountered (n = 48, 36.9%), followed by anti-c (n = 31, 23.8%) and anti-E (n = 15, 11.5%). In 65 of 130 pregnancies (50%), antibody concentrations triggered scans to screen for fetal anaemia. Of 130 pregnancies, 6 (4.6%) required intrauterine transfusions, and 31 of 130 (26%) neonates required post-natal intervention. Overall, morbidity was 0.1% and mortality 0.002%. CONCLUSIONS: This study demonstrates that morbidity and mortality caused by HDFN is minimal. These results are reassuring for women at risk of HDFN as even severely affected cases are successfully managed in most instances. Further studies are needed to identify predictors of disease severity.

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.

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.

Perinatal management of neonatal alloimmune thrombocytopenia associated with anti-group A antibody.

OBJECTIVE: To prevent neonatal alloimmune thrombocytopenia due to anti-group A antibody perinatal management was performed. BACKGROUND: We previously reported a case of severe intracranial haemorrhage associated with neonatal alloimmune thrombocytopenia due to anti-group A isoantibody. MATERIAL/METHODS: A 40-year-old Japanese woman, gravida 4 para 1, was pregnant with her second baby. The previous sibling developed severe thrombocytopenia and died 10 days after birth due to intracranial haemorrhage. He was diagnosed with neonatal alloimmune thrombocytopenia; the causative antibody was found to be the anti-group A antibody. Prednisone was started at 7 weeks' gestational age. Intravenous immunoglobulin 1 g kg(-1) week(-1) was started at 29 weeks' gestational age and continued to delivery. Serological studies and genotyping were performed. RESULTS: The second boy was delivered at 33 weeks' gestational age by caesarean section. He was discharged without intracranial haemorrhage or thrombocytopenia. The anti-group A antibody titre in the maternal serum was 2048-4096 (normal range: 4-64). The anti-group A antibody titre in the newborn's serum was 4. Cross-matching between the maternal serum and the paternal platelets was positive. CONCLUSION: Owing to the history of neonatal alloimmune thrombocytopenia causing intracranial haemorrhage and death of the previous sibling, strict follow-up of the subsequent pregnancy was conducted.

Fetomaternal hemorrhage (FMH), an update: review of literature and an illustrative case.

BACKGROUND: Blood trafficking from fetus to mother and vice versa is a well-known physiological event that occurs at any stage in pregnancy. If the fetus looses high blood quantities to the maternal blood stream it becomes symptomatic. These symptoms can vary from cardiovascular distress to fetal death. MATERIALS AND METHODS: We give a review of current literature on Fetomaternal hemorrhage (FMH). CONCLUSION: This article highlights the importance of physician's awareness on detecting this rare but life threatening entity with both severe consequences for mother and neonate. The traditional measurement of FMH and the co-usage of alpha-fetoprotein are debated. To conclude we describe and discuss an illustrative case of FMH. This article gives an applicatory overview of symptoms, diagnostics and treatment of FMH to facilitate physicians to detect this disease precociously.

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.

Screening for HLA antibodies in plateletpheresis donors with a history of transfusion or pregnancy.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is known as a life-threatening complication of transfusion. HLA and HNA antibodies have been associated with the immune pathway of TRALI. Since donors with a history of transfusion and/or pregnancy are presumed to have an increased risk of carrying such antibodies, we investigated the association of a history of transfusion or pregnancy with the occurrence of HLA alloimmunization in our donor population. STUDY DESIGN AND METHODS: A total of 1018 female plateletpheresis donors and male plateletpheresis donors with a history of transfusion were enrolled in the study. Included donors were systematically screened, using Luminex technology, for anti-HLA Class I and II. The association of donor history with HLA alloimmunization status was analyzed. RESULTS: The overall alloimmunization rate was 20.2%. In 0.0% of the nulliparous transfused female donors and in 1.3% of the transfused male donors, anti-HLA were detected. Thirty-one percent of the parous women versus 4.2% of the nulliparous women screened positive for anti-HLA. The rate of HLA alloimmunization increased with parity. CONCLUSION: Our data indicate that a history of transfusion is a minor risk factor for immunization against HLA antigens. In contrast, former pregnancies constitute a major risk factor for the development of HLA antibodies. Since HLA alloimmunization rate increases with parity, TRALI risk reduction measures should focus on this particular donor population. Repeated testing of female plateletpheresis donors after each pregnancy is implemented in our blood service.

Cerebral Doppler velocimetry to predict fetal anemia after more than three intravenous fetal exchange transfusions.

BACKGROUND: We aimed to assess usefulness of the middle cerebral artery peak systolic velocity (MCA-PSV) in the prediction of fetal anemia after more than three intravenous fetal-exchange transfusions (IFET). STUDY DESIGN AND METHODS: A retrospective study was conducted over 6 years of 15 consecutive pregnancies with severe red blood cell fetomaternal alloimmunization requiring more than three IFETs. We evaluated correlation between MCA-PSV (expressed as multiples of the mean [MoM]) and pretransfusion hemoglobin (Hb) in the fetus (MoM). Analyses were also performed to assess the value of MCA-PSV to predict moderate to severe fetal anemia. RESULTS: Twenty-seven MCA-PSV measurements performed before the fourth to last IFET were coupled with pretransfusion Hb in the fetus. The median number of IFETs per fetus was five (range, four to eight). Five Hb samples found fetuses with severe (19%), seven with moderate (26%), and 15 with mild anemia (56%). There was a linear correlation between MCA-PSV(x) and Hb in the fetus(y): y = -0.21x + 0.93 (r = -0.50, p < 0.01). For the prediction of moderate to severe anemia the negative predictive value of MCA-PSV with a threshold of 1.5 MoM was 75%, positive predictive value 73%, specificity 80%, sensibility 67%, and positive likelihood ratio 3.33. The area under the receiver operating characteristic curve was 0.78 (95% confidence interval, 0.59-0.96; p < 0.001). For the prediction of severe anemia, MCA-PSV with a threshold of 1.5 MoM had 94% negative predictive value, 80% sensibility, and a positive likelihood ratio of 2.5. CONCLUSIONS: This study shows that a correlation between MCA-PSV and Hb in the fetus persists even after more than three IFETs. MCA-PSV measurements thus remain useful to monitor fetuses at risk of anemia.

Red cell alloimmunisation following intrauterine transfusion and the feasibility of providing extended phenotype-matched red cell units.

OBJECTIVES: To analyse the incidence of additional alloantibody formation following intrauterine red cell transfusion and to evaluate the feasibility of providing extended phenotype-matched red cells in future intrauterine transfusion (IUT). BACKGROUND: IUT is performed in severe, life-threatening fetal anaemia, usually in alloimmunised pregnancies. Its complications include the formation of additional alloantibodies to other red cell antigens. MATERIALS AND METHODS: This was an 11-year retrospective, observational study of additional alloantibody formation in patients receiving IUT in the National Maternity Hospital, Dublin. The study included evaluation of the donor population in the Republic of Ireland (RoI) with regards to the feasibility of providing extended phenotype-matched units in future IUT. RESULTS: Following IUT, 22% of mothers formed additional red cell alloantibodies. In 67% of cases, the transfused donor red cells expressed the cognate antigen. Suitable donors are available for most combinations of Fy, Jk and Ss antigens. CONCLUSIONS: In our population, it is feasible to provide more extensively phenotype-matched red cells for future IUT. These can be supplied from the current donor pool with no significant extra phenotyping required. We consider their provision to be a reasonable proactive step in a known at-risk group.

Feto-maternal haemorrhage assessment in a woman with a large population of red blood cells containing fetal haemoglobin.

BACKGROUND: FMH quantification is necessary to calculate an individual dose of prophylactic anti-RhD immunoglobulin and to diagnose fetal anaemia causes. We encountered a healthy woman with a numerous RBCs containing fetal haemoglobin (HbF). AIMS: To investigate the cause of this sign and the correct evaluation of fetal RBCs in maternal circulation. MATERIALS AND METHODS: Patients samples and artificial mixtures were tested by microscopic Kleihaur-Betke (KB) and flow cytometric (FC) tests with anti-HbF + anti-CA (carbonic anhydrase), and with anti-D. The patient's blood count with reticulocyte parameters, and concentration of bilirubin, haptoglobin, iron, transferrin, ferritin, hepcidin, sTR, HbF, HbA2 were measured. Genes coding the beta- and gamma-globin were sequenced. RESULTS: It was impossible to distinguish the population of fetal and maternal HbF positive cells using KBT and FC with anti-HbF. Application of anti-CA and anti-D allowed to separate them. Maternal blood haematological and biochemical parameters were normal but HbF was 3.3% of total Hb concentration (normal < 1%). There were no mutations in the beta- and gamma-globin genes, but Xmn I polymorphism at -158 position in gamma-globin gene was detected in the homozygous state. CONCLUSION: A very large population of HbF positive cells sometimes can be detect in a healthy woman. Implementation of the various procedures for FMH assessment is necessary in the such case, otherwise, the detection of fetal erythrocytes may not be possible or can give false results.

The value of umbilical artery blood gas analysis in the rapid diagnosis of fetomaternal hemorrhage.

As a rare obstetric disease, fetomaternal hemorrhage (FMH) often causes severe fetal anemia, edema and even death, easily to be confused with severe neonatal asphyxia. Currently, there are several ways to detect or predict FMH, however, most of them are flawed and time-consuming, as well as unsuitable for rapid diagnosis and timely intervention of FMH. To explore the values of umbilical artery blood gas analysis in the rapid diagnosis of FMH, providing basis for rapid guidance of newborn rescue. Five cases of neonates with FMH from the First Affiliated Hospital of Army Military Medical University (Chongqing Southwest Hospital) from January 2013 to January 2016 were selected as the study group. Another 9 cases of severe asphyxia neonates were chosen into the control group. The difference in Apgar score and umbilical artery blood gas analysis between the 2 groups at birth was compared, and the treatments and clinical outcomes of the 2 groups were analyzed. The PH value of umbilical artery blood gas analysis in the study group was higher than that of the control group, but the difference was not statistically significant (P > .05). In the study group, cases with pH value < 7.0 accounted for 0%, whereas the cases with pH < 7.0 accounted for 66.67% in the control group, and the difference between the 2 groups was statistically significant (P < .05). Compared with the control group, the arterial oxygen partial pressure (PO2), the absolute value of (PCO2), lactic acid (lac) and alkali were not significantly different from those of the control group (P > .05), while the total hemoglobin (tHb) and hematocrit (Hct) were significantly lower than the control group (P < .0001). In the study group, tHb in the umbilical cord blood of 2 newborns with FMH death was significantly lower than 40 g/L. FMH should be highly suspected when there is an expression of severe asphyxia in neonates, indicated by significantly lower tHb levels in umbilical cord blood. It is helpful to improve the neonatal outcome by FMH neonatal resuscitation as soon as possible.

Applications of Flow Cytometry in Diagnosis and Evaluation of Red Blood Cell Disorders.

Clinical flow cytometry plays a vital role in the diagnosis and monitoring of various red blood cell disorders. The high throughput, precision, and automation potential of this technique allows for cost-effective and timely analysis compared to older and more manual test methods. Flow cytometric analysis serves as the gold standard diagnostic method for multiple hematological disorders, especially in clinical scenarios where an assay needs to have high sensitivity, high specificity, and a short turnaround time. In this review, we discuss the role of flow cytometric analysis in paroxysmal nocturnal hemoglobinuria, fetal-maternal hemorrhage, and hereditary spherocytosis.

Heterogeneity of F cells in ß-thalassemia.

BACKGROUND: Fetal hemoglobin (HbF), which is largely replaced after birth by the adult Hb, is concentrated in a few "F cells." Their number significantly increases in certain physiologic and clinical situations, including in ß-thalassemia (ß-thal). Their quantification is used to detect fetal-maternal hemorrhage (FMH), where fetal cells enter the maternal circulation. We were confronted with a pregnant woman with ß-thal who was suspected to have FMH. To establish the usefulness of a flow cytometric procedure to differentiate between fetal cells and the maternal F cells, we screened adult ß-thal patients. STUDY DESIGN AND METHODS: Blood samples were simultaneously stained with fluorescent antibodies to HbF and to carbonic anhydrase (CA) isotype II, which is specific to adult red blood cells (RBCs). RESULTS: A heterogeneous distribution of RBCs with respect to HbF and CA expression was observed: adult non-F cells (CA+HbF-) and F cells (CA+HbF+/HbF++) as well as F cells with characteristics of fetal cells (CA-HbF++). CONCLUSIONS: The presence of CA-HbF++ RBCs in nonpregnant women, and even men, with thal indicates that the CA/HbF method is inappropriate for detection of FMH. The coexistence of F cells carrying fetal or adult markers suggests that they originate from two types of stem cell, adult and fetal, lineages. Normally, the fetal lineage is insignificant, but in ß-thal, as HbF-containing RBCs have a selective advantage, the "fetal" lineage gains significance.