Intrauterine blood transfusion: current indications and associated risks

Pedagogical strategies in teaching invasive prenatal procedures: a scoping review protocol

INTRODUCTION

Invasive prenatal procedures (IPP) are core competencies in a Maternal-Fetal Medicine (MFM) fellowship training programme yet no standardised competency-based curriculum exists. This scoping review aims to provide a comprehensive understanding of the existing educational strategies for amniocentesis, chorionic villus sampling, fetal blood sampling and intrauterine blood transfusion. The objective is also to describe current gaps in the literature regarding evidence-based standards for training and assessment in IPP. Finally, we hope to encourage medical educators who are seeking to develop curricula based on competence by design to foster adaptive expertise through incorporating contextual variations in their teaching thus helping future MFM specialists to handle challenges and respond creatively to changing clinical circumstances and environmental variations.

METHODS AND ANALYSIS

Using the five-stage framework of Arksey and O'Malley's scoping review methodology as a guide, we will perform a systematic search in the Medline, Embase and Cochrane library databases to identify relevant studies on the educational strategies for IPP. We will include relevant English articles published after 1978. For a comprehensive search, we will explore websites and key journals, and hand-searched reference lists of key studies. Key studies are articles deemed relevant according to the specific inclusion and exclusion criteria. We will chart and sort data using a descriptive and thematic analysis approach.

ETHICS AND DISSEMINATION

This review will be the first to examine all forms of pedagogical strategies used in training invasive fetal procedures. As an analysis of pre-existing available data in the literature, this scoping review does not require ethical approval. We anticipate that results will identify research gaps as well as novel ideas for education strategies and assessment. Findings from this study will be disseminated through publication in a peer-reviewed journal, medical education and clinical conferences, and in knowledge translation settings, aiming to improve clinical practice and quality of care.

Correlation of fetal blood vessel Doppler measurements with fetal anemia among Rhesus isoimmunized pregnancies after two intrauterine transfusions

OBJECTIVE

To assess the correlation between fetal blood vessel Doppler measurements and fetal anemia among Rhesus isoimmunized pregnancies after two intrauterine transfusions as a potential guide to therapy.

METHODS

A prospective observational study was conducted among 30 women who attended a single hospital in India between April 2, 2015 and October 30, 2016. The participants underwent a third intrauterine transfusion based on a middle cerebral artery (MCA) peak systolic velocity (PSV) of greater than 1.50 multiples of the median (MoM). Cordocentesis was performed before the third intrauterine transfusion and hematocrit values correlated with the blood vessel Doppler measurements.

RESULTS

The MCA PSV MoM and fetal hematocrit MoM had a correlation coefficient of -0.43 (95% confidence interval -0.68 to 0.08; P=0.017). The sensitivity, specificity, positive predictive value, and negative predictive value were 68%, 57%, 83%, and 33%, respectively. The descending aorta PSV δ and fetal hematocrit δ had a correlation coefficient of -0.54 (95% confidence interval -0.75 to -0.23; P=0.001). An area under the curve of 0.80 (standard error 0.085; P=0.017) had 87% sensitivity and 57% specificity for diagnosing fetal anemia.

CONCLUSION

The descending aorta PSV could offer a useful diagnostic adjunct to MCA PSV after two intrauterine transfusions.

Intrauterine Transfusion Complicated by Umbilical Artery Thrombosis

Background

Fetal anemia results from several conditions; however intrauterine transfusion (IUT) remains the treatment for severe cases. The complications of this procedure are rare and yet can result in preterm delivery or fetal death.

Case

31 y/o G3P2002 with Rh alloimmunization underwent IUT from 19 to 35 weeks. Umbilical artery thrombosis was noted after her 5^th IUT. Further transfusions were performed without any complications and she delivered a full term male infant with APGARS of 8 and 9 at 1 and 5 minutes, respectively.

Conclusion

The complication of umbilical artery thrombosis is unusual and the optimal management is unclear. We report such a case and propose that the presence of Hyrtl's anastomosis near the placental cord insertion may explain the reassuring fetal status throughout the pregnancy.

Magnetic Resonance Imaging: A New Tool to Optimize the Prediction of Fetal Anemia?

INTRODUCTION

The false-positive rate in the prediction of fetal anemia is 10-15%. We investigated if a new, noninvasive MRI method used as a supplement to ultrasound could improve the prediction.

METHODS

Fetuses suspected of anemia and controls were scanned in a 1.5-tesla MRI scanner 1-4 times during pregnancy. Cases were scanned before and after intrauterine blood transfusion with a T1-mapping MRI sequence in a cross-section of the umbilical vein.

RESULTS

Inclusion of 8 cases and 11 controls resulted in 10 case scans (2 cases were included twice) and 33 control scans. In controls, the T1 relaxation time was 1,005-1,391 ms; in cases with severe anemia, 1,505-1,595 ms, moderate anemia 1,503-1,525 ms, and no/mild anemia 1,245-1,410 ms. After blood transfusions, values dropped to 1,123-1,288 ms. The mean value in moderate and severe anemic cases was 275 ms higher than in controls (95% CI 210-341 ms, p < 0.0001), and after blood transfusion it was comparable to controls (3 ms, 95% CI -62 to 68 ms, p = 0.934). A 1,450-ms cut-off would have identified all cases in need of blood transfusion with no false-positive cases.

CONCLUSIONS

Our findings indicate a potential for this new MRI method to improve the prediction of fetal anemia as a supplement to ultrasound.

Fetal anemia: Diagnosis and management

Fetal anemia has been known for many years as a dangerous complication of pregnancy. Its most common causes are maternal alloimmunization and parvovirus B19 infection, although it can be associated with many different pathological conditions including fetal aneuploidies, vascular tumors, and arteriovenous malformations of the fetus or placenta and inherited conditions such as alpha-thalassemia or genetic metabolic disorders. Doppler ultrasonographic assessment of the peak velocity of systolic blood flow in the middle cerebral artery for the diagnosis of fetal anemia and intravascular intrauterine transfusion for its treatment are the current practice standards. Live birth rates as high as 95% have been reported in recent years. The additional role of intravenous immunoglobulin therapy and the long-term consequences of the condition are the subjects of active ongoing research.

Efficacy of Antenatal Intravenous Immunoglobulin Treatment in Pregnancies at High Risk due to Alloimmunization to Red Blood Cells

Background

Alloimmunization to red blood cells (RBCs) may result in fetal anemia prior to 20 weeks gestation. The question as to whether early commencement of antenatal treatment with high-dose intravenous immunoglobulins (IVIG) may prevent or at least delay the development of fetal anemia in the presence of alloantibodies to RBCs is highly relevant.

Patients and Results

Here we describe a patient with high-titer anti-K and two other severely affected pregnant women with a history of recurrent pregnancy loss due to high-titer anti-D or anti-D plus anti-C. Early commencement of treatment with IVIG (1 g/kg/week) resulted in prevention of intrauterine transfusion (IUT) in the former two cases, and in a significant delay of development of fetal anemia in the remaining case (26 weeks gestation).

Conclusion

Based on our findings and of previously published cases, early initiation of treatment of severely alloimmunized women with IVIG (1 g/kg/week) could potentially improve the outcome of fetuses at risk.

Fetal anemia

The diagnosis and management of fetal anemia has been at the forefront of advances in the fields of fetal physiology, immunology, fetal imaging, and fetal therapy among others. Alloimmunization and parvovirus infection are the leading cause of fetal anemia in the United States. The middle cerebral artery peak systolic velocity (MCA-PSV) diagnoses fetal anemia. Its discovery is considered one of the most important achievements in fetal medicine. Accumulation of experience in recent years as well as refinement of surgical techniques have led to safer invasive procedures. It is expected that long term follow-up of affected pregnancies, continues to reflect all these improvements in care. It is also expected that treatment of other less common causes of fetal anemia becomes more frequently reported and that the management principles of fetal anemia are successfully applied to other fetal pathologies.

The Recurrence Risk of Fetomaternal Hemorrhage

Massive fetomaternal hemorrhage (FMH) can cause devastating pregnancy outcomes. Perinatal prognosis may be improved by intrauterine transfusion, but the appropriate management for these pregnancies remains unclear. To determine the recurrence risk of FMH after intrauterine transfusion, we performed a systematic review of all case reports/series of patients with proven FMH treated with intrauterine transfusion and who had subsequent follow-up of at least 72 h until delivery. This revealed 13 cases, with 1 additional case from our institution. Ten patients (71.4%) had a second episode of FMH requiring a second intrauterine transfusion. Five patients (35.7%) required at least 3 intrauterine transfusions. The time interval between intrauterine transfusions was progressively reduced. The gestational age at the onset of signs/symptoms was 26.6 ± 2.1 weeks, and gestational age at delivery was 34.2 ± 4.2 weeks. Two cases of fetal demise (14.3%) and no neonatal deaths were recorded. Limited postnatal follow-up on 8 neonates was normal. The mean neonatal hemoglobin and transfusion rates were 13.2 ± 5.7 g/dL and 33.3%, respectively. Close fetal monitoring, likely daily, is necessary to recognize FMH recurrence. Several transfusions may be necessary once FMH is diagnosed if pregnancy is allowed to continue > 72 h.

Congenital Viral Infection: Traversing the Uterine-Placental Interface

Why certain viruses cross the physical barrier of the human placenta but others do not is incompletely understood. Over the past 20 years, we have gained deeper knowledge of intrauterine infection and routes of viral transmission. This review focuses on human viruses that replicate in the placenta, infect the fetus, and cause birth defects, including rubella virus, varicella-zoster virus, parvovirus B19, human cytomegalovirus (CMV), Zika virus (ZIKV), and hepatitis E virus type 1. Detailed discussions include ( a) the architecture of the uterine-placental interface, ( b) studies of placental explants ex vivo that provide insights into the infection and spread of CMV and ZIKV to the fetal compartment and how these viruses undermine early development, and ( c) novel treatments and vaccines that limit viral replication and have the potential to reduce dissemination, vertical transmission and the occurrence of congenital disease.

Red Blood Cell Alloimmunization in the Pregnant Patient

Alloimmunization to red blood cell (RBC) antigens represents a challenge for physicians caring for women of child bearing potential. Exposure to non-self RBC antigens may occur during transfusion or pregnancy leading to the development of antibodies. If a subsequent fetus bears that antigen, maternal antibodies may attack the fetal red blood cells causing red cell destruction and clinically significant hemolytic disease of the fetus and newborn (HDFN). In the most severe cases, HDFN may result in intrauterine fetal demise due to high output cardiac failure, effusions and ascites, known as "hydrops fetalis". This article reviews strategies for management and prevention of RBC alloimmunization in women of child bearing potential.

Perinatal Care of Infants with Congenital Birth Defects

Prenatal diagnosis has changed perinatal medicine dramatically, allowing for additional fetal monitoring, referral and counseling, delivery planning, the option of fetal intervention, and targeted postnatal management. Teams participating in the delivery room care of infants with known anomalies should be knowledgeable about specific needs and expectations but also ready for unexpected complications. A small number of neonates will need rapid access to postnatal interventions, such as surgery, but most can be stabilized with appropriate neonatal care. These targeted perinatal interventions have been shown to improve outcome in selected diagnoses.

Preclinical Canine Model of Graft-versus-Host Disease after In Utero Hematopoietic Cell Transplantation

In utero hematopoietic cell transplantation (IUHCT) offers the potential to achieve allogeneic engraftment and associated donor-specific tolerance without the need for toxic conditioning, as we have previously demonstrated in the murine and canine models. This strategy holds great promise in the treatment of many hematopoietic disorders, including the hemoglobinopathies. Graft-versus-host disease (GVHD) represents the greatest theoretical risk of IUHCT and has never been characterized in the context of IUHCT. We recently described a preclinical canine model of IUHCT, allowing further study of the technique and its complications. We aimed to establish a threshold T cell dose for IUHCT-induced GVHD in the haploidentical canine model and to define the GVHD phenotype. Using a range of T cell concentrations within the donor inoculum, we were able to characterize the phenotype of IUHCT-induced GVHD and establish a clear threshold for its induction between 3% and 5% graft CD3⁺ cell content. Given the complete absence of GVHD at CD3 doses of 1% to 3% and the excellent engraftment with the lowest dose, there is a safe therapeutic index for a clinical trial of IUHCT.

Pediatric red cell and platelet transfusions

The aim of pediatric transfusions should be based on the concept of avoiding unnecessary transfusions without jeopardizing the patient safety and providing correct blood components when there are well founded indications to transfuse. Despite considerable efforts from transfusion services to increase transfusion safety, transfusions are still associated with preventable and unpreventable adverse effects that may, in the worst case, have severe and fatal consequences. Transfusions to pediatric patients constitute a small proportion of all transfusions but have higher incidence of adverse events compared to adults. Pediatric transfusions consist of intrauterine transfusions, top-up transfusions to neonates and young children, exchange transfusions in the management of hemolytic disease of newborn (HDN), in addition to sickle cell crisis, chronic transfusion therapy in thalassemia patients, massive transfusion in trauma, HLA- and HPA-compatible platelets in immunized patients and neonates with fetal neonatal alloimmune thrombocytopenia (FNAIT). Packed red cells (PRCs) and platelet (PLT) concentrates are the most utilized blood components and will be reviewed here.

Sonographic Demonstration of Intracranial Hemorrhage in a Fetus with Hydrops Fetalis due to Rh Alloimmunization after Intrauterine Intravascular Transfusion: A Case Report and Review of the Literature

Intrauterine transfusion is the most common and successful intrauterine procedure for the treatment of fetal anemia due to red cell alloimmunization. Fetal intracranial hemorrhage is a very rare complication of intrauterine transfusion in patients with Rh(D) alloimmunization and it has been demonstrated only in a few case reports in the literature. Herein, we described a case of grade IV intraventricular hemorrhage that was diagnosed following the first intrauterine transfusion and reviewed the literature about the fetal intracranial hemorrhage that occurred after intrauterine intravascular transfusion procedure.

Intrauterine Fetal Blood Transfusion: Descriptive study of the first four years' experience in Oman

OBJECTIVES

Haemolytic disease of the fetus and newborn (HDFN) causes hydrops fetalis. The successful treatment of HDFN has been reported with intrauterine blood transfusion (IUT). This study aimed to describe the initial experience with IUT procedures in Oman.

METHODS

This retrospective observational study took place at the Royal Hospital and Sultan Qaboos University Hospital Blood Bank, Muscat, Oman, and included all women who underwent IUT procedures in Oman between March 2012 and March 2016. Gestational and neonatal outcomes were assessed, including complications, morbidity, neurodevelopmental sequelae and mortality.

RESULTS

A total of 28 IUT procedures for 13 fetuses carried by 11 women were performed. Gestational age at the time of referral ranged from 13-30 weeks, while the median gestational age at first IUT procedure was 26 weeks (range: 19-30 weeks). Indications for the procedure included HDFN caused by anti-D (n = 6), a combination of anti-D and anti-C (n = 4), anti-K (n = 1) and anti-Jsb (n = 1) antibodies and nonimmune hydrops fetalis due to a congenital parvovirus infection (n = 1). Median fetal haemoglobin levels at the beginning and end of the procedure were 4.6 g/dL and 12.8 g/dL, respectively. Most procedures were transplacental intravascular transfusions through the placental umbilical cord root (71.4%), followed by transamniotic intravascular transfusions (14.3%). The overall survival rate was 61.5%, with five deaths; of these, four were intrauterine and one was an early neonatal death due to non-resolved hydrops and severe cardiac dysfunction.

CONCLUSION

As a relatively novel obstetric procedure in Oman, IUT seems to result in a favourable outcome for hydropic fetuses.

Parvovirus B19 infection in pregnancy-awareness and opportunities

Parvovirus B19 (B19V) is a human pathogenic virus associated with a wide range of clinical conditions. In pregnancy, B19V poses a potential hazard to the fetus as crossing the placental barrier and infecting erythroid progenitor cells in bone marrow and liver, it blocks fetal erythropoiesis leading to profound anemia, hydrops and/or fetal death. The virus is not regarded as a teratogen, however more scientific awareness is emerging on mechanisms and consequences of intrauterine infection and possible sequelae in the neonatal development. Reliable diagnostic procedures and fetal management strategies, including intrauterine transfusion, are established. In spite of being a recognized fetotropic agent possibly leading to fetal loss, testing for B19V is not routinely included in preconception or antenatal screenings, possibly delaying the management of B19V-complicated pregnancies. Continuous advances in B19V research will provide for better diagnostic methods and algorithms, as well as for the development of effective prophylactic interventions and novel therapeutic options.

Persistence of Villous Immaturity in Term Deliveries Following Intrauterine Transfusion for Parvovirus B19 Infection and RhD-associated Hemolytic Disease of the Fetus and Newborn

Common causes of fetal anemia and hydrops include parvovirus B19 infection during the first 2 trimesters of pregnancy, as well as maternal alloimmunization to RhD with subsequent hemolytic disease of the fetus and newborn (HDFN) in an RhD positive fetus. Although both of these conditions have historically caused significant fetal morbidity and mortality, the advent of intrauterine transfusion (IUT) over the last few decades has dramatically improved outcomes. Prior literature has extensively documented placental changes associated with untreated parvovirus infection and RhD HDFN in intrauterine fetal demises and preterm births; however, histopathologic changes in term placentas from term infants treated with IUT have not been reported. We present placental findings in 2 cases of parvovirus B19-associated hydrops and 2 cases of RhD HDFN-associated hydrops in term infants after IUT, highlighting unique aspects that may be diagnostically useful for the examining pathologist.

Histologic Chorioamnionitis and Funisitis After Laser Surgery for Twin-Twin Transfusion Syndrome

OBJECTIVE

To estimate the incidence of histologic chorioamnionitis and funisitis after fetoscopic laser surgery for the management of twin-twin transfusion syndrome.

METHODS

A case-control study was performed at the Leiden University Medical Center from 2013 to 2014. All patients with twin-twin transfusion syndrome managed with laser surgery during the study period were included and compared with a control group of all monochorionic twins not treated with laser surgery. We excluded patients with fetal demise or higher order pregnancies. Placentas were reviewed for the presence and degree of chorioamnionitis and presence or absence of fetal inflammatory response. The primary outcome was the incidence of histologic chorioamnionitis and funisitis after laser surgery. Odds ratios (ORs) and 95% confidence intervals (CIs) for primary outcomes were calculated. A P value of <.05 was considered as statistical significance.

RESULTS

Sixty-two patients treated with laser surgery were included in the study group and compared with 64 patients in the control group. The incidence of histologic chorioamnionitis was 13% (8/62) in the laser group compared with 5% (3/64) in the control group (OR 3.0, 95% CI 0.8-11.9, P=.12). Funisitis occurred in 8% (10/124) in the laser group compared with 0% in the control group (OR 11.1, 95% CI 1.3-96.9, P=.03). Histologic chorioamnionitis with or without funisitis after laser surgery was associated with a shorter laser-to-delivery interval (median 6.6 [range 3.4-14.1] compared with 13.6 [4.4-20.1] weeks, P<.01) and lower gestational age at birth (median 28.1 [range 23.1-32.6] compared with 32.7 [24.4-37.0] weeks, P<.01).

CONCLUSION

These findings suggest that laser surgery for twin-twin transfusion syndrome is associated with an increased risk of funisitis.

In utero treatment of severe fetal anemia resulting from fetomaternal red blood cell incompatibility: a comparison of simple transfusion and exchange transfusion

OBJECTIVE

To compare in utero exchange transfusions (IUET) and in utero simple transfusions (IUST) for the treatment of fetal anemia resulting from red blood cell fetomaternal incompatibility.

STUDY DESIGN

Retrospective comparative study from January 2006 through December 2011. The two techniques were compared for effectiveness, complications, and neonatal outcomes.

RESULTS

36 patients had 87 IUETs and 85 patients 241 IUSTs. Gestational age at the first transfusion was similar in both groups (IUET: 27±3.8 weeks; IUST: 27±4.7 weeks; NS) as was the initial fetal hemoglobin level (IUET: 6.4±2.8g/dL; IUST: 6.0±2.5g/dL; NS). No significant differences were noted for postprocedure complications or efficacy. The daily drop in hemoglobin level was similar in both groups (IUET: 0.41±0.23g/dL/day; IUST: 0.44±0.17g/dL/day; NS) as were the time intervals between two procedures. Gestational age at birth was earlier in the IUET group (34.4±1.3 weeks vs 35.5±1.8 weeks; p<0.001), but the postnatal transfusions or exchange transfusions rates and the duration of intensive phototherapy did not differ. No significant differences were noted for the overall survival rates (IUET: 100%; IUST: 96.4%; p>0.99).

CONCLUSION

IUET does not appear to provide any benefits compared with IUST, neither to be associated with a higher complication rate. The choice of the technique depends on availability of packed blood cells with high hematocrit (70-80%).

Perinatal survival and procedure-related complications after intrauterine transfusion for red cell alloimmunization

OBJECTIVES

To study the perinatal survival and procedure-related (PR)complications after intrauterine transfusions in red cell alloimmunization.

METHODS

Prospective data of 102 women with Rh-alloimmunized pregnancy undergoing intrauterine intravascular transfusion for fetal anemia, from January 2011 to October 2014 were analyzed. Main outcome measures were perinatal survival and procedure-related (PR) complications.

RESULTS

A total of 303 intrauterine transfusions were performed in 102 women. Of 102 fetuses, 22 were hydropic at first transfusion. The mean period of gestation and hematocrit at first transfusion was 26.9 ± 3.3 weeks (range 19.7-33.8 weeks) and 17 ± 7.82 % (range 5.7-30 %), respectively. Average number of transfusions was 2.97 (range 1-7) per patient. Overall survival was 93 % and mean period of gestation at delivery was 34.5 ± 1.94 (range 28.3-37.4) weeks. Mean hematocrit at delivery was 36.9 ± 8.77 % (range 10-66 %). Fetal death occurred in four cases (3PR), neonatal death occurred in three cases (2PR). Emergency cesarean delivery after transfusion was performed in four pregnancies. The total PR complication rate was 2.97 %, resulting in overall PR loss in 1.65 % per procedure.

CONCLUSION

Our results compare favorably with other studies published in the literature. Intravascular transfusion is a safe procedure improving perinatal survival in fetuses with anemia due to Rh-alloimmunization.

Changes in fetal myocardial performance index following intravascular transfusion: preliminary report

OBJECTIVE

To investigate the changes in fetal left ventricle myocardial performance index (MPI) following intrauterine intravascular transfusion (IUT).

METHODS

Prospective study, including 25 IUT performed in 13 singleton pregnancies with maternal Rh D alloimmune disease. Left ventricle MPI was evaluated prior to transfusion and repeated 24 h after each procedure. Delta MPI was calculated as the difference between post- and pre-transfusion MPI z-scores. Multilevel regression analysis was used to examine the association between delta MPI and gestational age at procedure, fetal middle cerebral artery peak velocity MoM, pre- and post-MPI and hemoglobin z-score values, the volume of blood transfused and feto-placental volume percentage expansion. Adjustments were made for repeated measurements within the same fetus, and across different time points. The significance level was set as 0.05.

RESULTS

MPI z-score values increased significantly following transfusion (delta MPI = 1.10 ± 2.47, p=0.036). Delta MPI showed a significant correlation with gestational age at transfusion (r= -0.47, p=0.018), pre-transfusion MPI z-score (r= -0.50, p=0.012) and feto-placental volume percentage expansion (r= -0.41, p=0.044).

CONCLUSION

Left ventricle MPI increases significantly after intrauterine blood transfusion and greater changes are associated with procedures at an earlier gestational age, lower pre-transfusion MPI z-scores and smaller feto-placental volume expansion.

Stem cell transplantation before birth - a realistic option for treatment of osteogenesis imperfecta?

Osteogenesis imperfecta (OI) is characterized by severe bone deformities, growth retardation and bones that break easily, often from little or no apparent cause. OI is a genetic disorder primarily with defective type I collagen with a wide spectrum of clinical expression. In the more severe cases, it can be diagnosed before birth. Transplantation of mesenchymal stem cells (MSC) has the potential to improve the bone structure and stability, growth and fracture healing. Prenatal and postnatal cell transplantation has been investigated in preclinical and clinical studies of OI and suggests that this procedure is safe and has positive effects. Cell transplantation resulted in improved linear growth, mobility and reduced fracture incidence. However, the effect is transient and for this reason re-transplantation may be needed. So far there is limited experience in this area, and proper studies are required to accurately determine if MSC transplantation is of clinical benefit in the treatment of OI. In this review, we summarize what is currently known in this field.