Fetomaternal transfusion as a cause of severe fetal anemia causing early neonatal death: a case report

Red Blood Cell Alloimmunization in Pregnancy: A Review of the Pathophysiology, Prevalence, and Risk Factors

This review paper provides an overview of the risk factors and laboratory testing for red blood cell (RBC) alloimmunization in pregnancy. RBC alloimmunization is a significant medical issue that can cause haemolytic disease of the fetus and newborn (HDFN), leading to neonatal morbidity and mortality. Current HDFN prophylaxis targets only Rhesus D (RhD) alloimmunization, with no effective measures to prevent alloimmunization to other RBC antigen groups. Several factors can increase the risk of developing RBC alloimmunization during pregnancy, including fetomaternal haemorrhage, RBC and maternal genetic status, and previous transfusions. Identifying these risk factors is essential to execute the appropriate management strategies to minimize the risk of HDFN. The review also discusses the laboratory methods and overview of pregnancy management. The paper highlights the importance of identifying and managing the risk factors for RBC alloimmunization in pregnancy to minimize the risk of HDFN and improve neonatal outcomes.

Why does second trimester demise of a monochorionic twin not result in acardiac twinning?

Background

We previously explained why acardiac twinning occurs in the first trimester. We raised the question why a sudden demised monochorionic twin beyond the first trimester does not lead to acardiac twinning. We argued that exsanguinated blood from the live twin would strongly increase the demised twins' vascular resistance, preventing its perfusion and acardiac onset. However, our current hypothesis is that perfusion of the demised twin does occur but that it is insufficient for onset of acardiac twinning.

Methods

We analyzed blood pressures and flows in a vascular resistance model of a monochorionic twin pregnancy where one of the fetuses demised. The resistance model consists of a demised twin with a (former) placenta, a live twin and its placenta, and arterioarterial (AA) and venovenous placental anastomoses. We assumed that only twins with a weight of at least 33% of normal survived the first trimester and that exsanguination of more than 50% of its blood volume is fatal for the live twin.

Results

At 20 weeks, only AA anastomoses with radii ≲1 mm keep the exsanguinated blood volume below 50%. Then, perfusion of the deceased body with arterial blood from the live fetus is about 5–40 times smaller than when that body was alive. Beyond 20 weeks, this factor is even smaller. At 14 weeks, this factor is at most 2.

Conclusion

We hypothesize that this small perfusion flow of arterial blood prevents further growth of the deceased body and hence precludes onset of acardiac twinning.

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.

Untimely diagnosis of fetomaternal hemorrhage: what went wrong?

Fetomaternal hemorrhage (FMH) is an obstetrical challenge. It is defined as a passage of fetal blood into the maternal circulation or vice versa, which might complicate pregnancy or delivery. Most cases of acute and chronic FMH are idiopathic in origin and involve uncomplicated near-term pregnancies. Yet, due to the lack of universal screening, heterogeneous clinical presentation and insufficient clinicians awareness, in some cases FMH may present as immediate fetal compromise or even stillbirth as the most devastating consequence. We made a review of the literature of the FMH clinical cases of fetal/neonatal death in order to focus on the available diagnostic tools and their limitations. Cardiotocography, biophysical profile, middle cerebral artery peak systolic volume and current laboratory tests were studied and evaluated as diagnostic tools for FMH. International guidelines are needed to help clinicians make a prompt identification of FMH. Moreover, a standardized management protocol is essential in order to improve fetal-neonatal outcomes.

Effects of HIV infection on maternal and neonatal health in southern Mozambique: A prospective cohort study after a decade of antiretroviral drugs roll out

Introduction

The HIV epidemic is concentrated in sub-Saharan Africa. However, limited information exists on its impact on women and infant’s health since the introduction of antiretroviral drugs in this region, where health resources are often scarce.

Methods

The effect of HIV infection on maternal health, birth outcomes and infant health was analysed in two contemporary cohorts of HIV-uninfected and HIV-infected pregnant women from southern Mozambique. Pregnant women attending the first antenatal care visit were followed until one month after delivery. Antiretroviral therapy was administered based on CD4+T cell count and clinical stage. Maternal and neonatal morbidity and mortality, as well as pregnancy outcomes were assessed by mother’s HIV status.

Results

A total of 1183 HIV-uninfected and 561 HIV-infected pregnant women were enrolled. HIV-infected women were more likely to have anaemia both at the first antenatal care visit and at delivery than HIV-uninfected women (71.5% versus 54.8% and 49.4% versus 40.6%, respectively, p<0.001). Incidence of hospital admissions during pregnancy was increased among HIV-infected women (RR, 2.04, [95%CI, 1.45; 2.86]; p<0.001). At delivery, 21% of HIV-infected women reported being on antiretroviral therapy, and 70% having received antiretroviral drugs for prevention of mother to child transmission of HIV. The risk of stillbirths was doubled in HIV-infected women (RR, 2.16 [95%CI 1.17; 3.96], p = 0.013). Foetal anaemia was also increased among infants born to HIV-infected women (10.6% versus 7.3%, p = 0.022). No differences were found in mean birth weight, malaria, prematurity and maternal and neonatal deaths between groups.

Conclusions

HIV infection continues to be associated with significant maternal morbidity and poor neonatal health outcomes. Efforts should urgently be made to identify the barriers that impede improvements on the devastating effects of HIV in African women and their infants.

Trial registration

ClinicalTrials.gov NCT 00811421.

Term pregnancy with choriocarcinoma presenting as severe fetal anemia and postpartum hemorrhage

OBJECTIVE

Term pregnancy with choriocarcinoma is a rare condition that can be a serious health threat to both the mother and the fetus. We present a rare case of term pregnancy with choriocarcinoma presenting as severe fetal anemia and postpartum hemorrhage.

CASE REPORT

A 34-year-old woman, gravida 3 para 2, was admitted for profuse vaginal bleeding 2 weeks after cesarean delivery of a full-term anemic baby. Transvaginal sonography revealed a 4.7-cm×10.6-cm heterogenous lesion in the endometrial cavity. Dilatation and curettage was done and a pathologic report revealed choriocarcinoma. Metastatic workup showed lung metastasis. The patient achieved remission after eight cycles of chemotherapy in the form of etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine. There was no evidence of recurrence in the subsequent 3 years of regular follow up.

CONCLUSION

Although fetomaternal hemorrhage is a rare form of presentation of choriocarcinoma, its presence should alert the physician to investigate the cause further. This chemotherapy regimen was effective in our case and the patient needed to be followed up carefully.

Society for maternal-fetal medicine (SMFM) clinical guideline #7: nonimmune hydrops fetalis

OBJECTIVE

Nonimmune hydrops is the presence of ≥2 abnormal fetal fluid collections in the absence of red cell alloimmunization. The most common etiologies include cardiovascular, chromosomal, and hematologic abnormalities, followed by structural fetal anomalies, complications of monochorionic twinning, infection, and placental abnormalities. We sought to provide evidence-based guidelines for the evaluation and management of nonimmune hydrops fetalis.

METHODS

A systematic literature review was performed using MEDLINE, PubMed, EMBASE, and Cochrane Library. The search was restricted to English-language articles published from 1966 through June 2014. Priority was given to articles reporting original research, although review articles and commentaries also were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion in this document. Evidence reports and guidelines published by organizations or institutions such as the National Institutes of Health, Agency for Health Research and Quality, American Congress of Obstetricians and Gynecologists, and Society for Maternal-Fetal Medicine were also reviewed, and additional studies were located by reviewing bibliographies of identified articles. Grading of Recommendations Assessment, Development, and Evaluation methodology was employed for defining strength of recommendations and rating quality of evidence. Consistent with US Preventive Task Force guidelines, references were evaluated for quality based on the highest level of evidence.

RESULTS AND RECOMMENDATIONS

Evaluation of hydrops begins with an antibody screen (indirect Coombs test) to determine if it is nonimmune, detailed sonography of the fetus(es) and placenta, including echocardiography and assessment for fetal arrhythmia, and middle cerebral artery Doppler evaluation for anemia, as well as fetal karyotype and/or chromosomal microarray analysis, regardless of whether a structural fetal anomaly is identified. Recommended treatment depends on the underlying etiology and gestational age; preterm delivery is recommended only for obstetric indications including development of mirror syndrome. Candidates for corticosteroids and antepartum surveillance include those with an idiopathic etiology, an etiology amenable to prenatal or postnatal treatment, and those in whom intervention is planned if fetal deterioration occurs. Such pregnancies should be delivered at a facility with the capability to stabilize and treat critically ill newborns. The prognosis depends on etiology, response to therapy if treatable, and the gestational age at detection and delivery. Aneuploidy confers a poor prognosis, and even in the absence of aneuploidy, neonatal survival is often <50%. Mirror syndrome is a form of severe preeclampsia that may develop in association with fetal hydrops and in most cases necessitates delivery.

Effect of neonatal hemoglobin concentration on long-term outcome of infants affected by fetomaternal hemorrhage

BACKGROUND

Fetomaternal hemorrhage (FMH) can cause severe morbidity. However, perinatal risk factors for long-term poor outcome due to FMH have not been extensively studied.

AIMS

To determine which FMH infants are likely to have neurological sequelae.

STUDY DESIGN

A single-center retrospective observational study. Perinatal factors, including demographic characteristics, Kleihauer-Betke test, blood gas analysis, and neonatal blood hemoglobin concentration ([Hb]), were analyzed in association with long-term outcomes.

SUBJECTS

All 18 neonates referred to a Neonatal Intensive Care Unit of Kagoshima City Hospital and diagnosed with FMH during a 15-year study period. All had a neonatal [Hb] <7.5g/dL and 15 of 17 neonates tested had Kleihauer-Betke test result >4.0%.

OUTCOME MEASURES

Poor long-term outcome was defined as any of the following determined at 12 month old or more: cerebral palsy, mental retardation, attention deficit/hyperactivity disorder, and epilepsy.

RESULTS

Nine of the 18 neonates exhibited poor outcomes. Among demographic characteristics and blood variables compared between two groups with poor and favorable outcomes, significant differences were observed in [Hb] (3.6±1.4 vs. 5.4±1.1g/dL, P=0.01), pH (7.09±0.11 vs. 7.25±0.13, P=0.02) and base deficits (17.5±5.4 vs. 10.4±6.0mmol/L, P=0.02) in neonatal blood, and a number of infants with [Hb]≤4.5g/dL (78%[7/9] vs. 22%[2/9], P=0.03), respectively. The base deficit in neonatal arterial blood increased significantly with decreasing neonatal [Hb].

CONCLUSIONS

Severe anemia causing severe base deficit is associated with neurological sequelae in FMH infants.

Incidence, diagnosis and pathophysiology of amniotic fluid embolism

Amniotic fluid embolism (AFE) is a rare clinical entity, sometimes fatal. A review was conducted to describe the frequency, diagnosis and pathophysiology of AFE. The reported incidences ranged from 1.9 cases per 100,000 maternities (UK) to 6.1 per 100,000 maternities (Australia), which can vary considerably, depending on the period, region of study and the definition. Although the development of amniotic fluid-specific markers would have an impact on early diagnosis, definition of AFE based on these markers is not widely accepted. To date, immunological mechanisms, amniotic fluid-dependent anaphylactic reaction and complement activation, have been proposed as potential pathogenetic and pathophysiological mechanisms. Immune cell activation induced through complement activation may be associated with the mechanism that immediately initiates maternal death, only in susceptible individuals. This review will focus on advances in the field of AFE biology and discuss the prevalence, diagnosis and pathophysiology of AFE.

Severe neonatal anemia from fetomaternal hemorrhage: report from a multihospital health-care system

OBJECTIVE

The incidence of fetomaternal hemorrhage that is severe enough to cause neonatal anemia is not known. Owing to its relative rarity, much of the literature describing this condition is in the form of case reports and small case series. We performed a large, muiticentered, sequential, case series to determine the incidence, antecedents and outcomes.

STUDY DESIGN

From the multicentered databases of Intermountain Healthcare, we obtained records of all neonates with hematocrit (Hct) <30% or hemoglobin (Hgb) <10 g dl(-1) on the day of birth, who had Kleihauer-Betke staining or flow cytometric evidence of fetomaternal hemorrhage.

RESULT

Among 219,853 live births, 24 had anemia with evidence of fetomaternal hemorrhage (incidence estimate, 1 per 9160 live births). The initial Hgb ranged from 1.4 to 10.2 g dl(-1) (Hct 29.8%). The initial Hgb was <7 g dl(-1) in 18 (67%), <5 g dl(-1) in 12 (50%) and was <3 g dl(-1) in 7 (29%). All 7 mothers in whom neonatal Hgb was <3 g dl(-1) had reported absent fetal movement, as did 13 of 18 mothers when the initial Hgb was <7 g dl(-1). Outcomes were poorer in those with the lowest initial Hgb; in the two lowest, one died on day 1, and the other developed a grade 4 intraventricular hemorrhage (IVH). The adverse outcomes of death, IVH, periventricular leukomalacia, bronchopulmonary dysplasia or hypoxic-ischemic encephalopathy were common; occurring in 71% (17 of the 24), including all with an initial Hgb <5 g dl(-1) and all born at ≤35 weeks of gestation.

CONCLUSION

Fetomaternal hemorrhage is a rare but sometimes devastating condition. Those with fetomaternal hemorrhage and an initial Hgb of <5 g dl(-1) are expected to need resuscitation at birth, to receive emergent transfusion support and to be at risk for death and major morbidities. Antenatal suspicion of this diagnosis should occur when absent fetal movement is reported. Improvements in rapid diagnosis are needed to prepare first responders and transfusion services.

Massive idiopathic feto-maternal transfusion associated with dilatation of umbilical vein: case report and review of literature

Feto-maternal transfusion (FMT) or haemorrhage occurs when there is an entry of fetal blood into the maternal circulation in pregnancy or during delivery. It has been stated that very small amount of fetal red cells are normally detectable in maternal circulation in all pregnancies. However, massive FMT is rare and even rarer is the resultant severe anaemia which may cause severe fetal morbidity or early neonatal death in apparently uneventful normal pregnancy. Massive FMT is regarded as a pathological condition with a variety of clinical presentations essentially secondary to the fetal anaemia. We present a case of FMT associated with umbilical vein dilation and speculate whether this finding is of prognostic value.

The entry of fetal and amniotic fluid components into the uterine vessel circulation leads to sterile inflammatory processes during parturition

Pro-inflammatory cytokines play an important role during the process of human parturition. The focus of this review was to explore the contribution of biological, biochemical, and genetic changes in the onset of term labor. This article reviews the English-language literature on inflammatory, hormonal, and immunological factors in an effort to identify the molecular basis of human parturition. The majority of the genes and proteins up-regulated in parturition at term are related to four functional categories, mechanical stretch-mediated damage-associated molecular patterns (DAMPs) activation, response to immunity, induction of inflammatory signaling, and progressive uterine myometrial contractility and resultant term birth. Mechanical stretch could promote the entry of amniotic fluid components into the uterine vessel circulation that is the common physiologic mechanism at term prior to labor. The fetal or amniotic fluid-derived DAMPs could activate the immune system. The inflammatory mediators are produced by infiltrating activated leukocytes and by the reproductive tissues themselves such as myometrium, and subsequently lead to uterine contractions. This review supports the sterile inflammation hypothesis that there are at least two phases of human parturition: the initial wave of the entry of amniotic fluid components into uterine vasculatures would be followed by the second big wave of subsequent myometrial contraction.