Monitoring and management of hemolytic disease of the fetus and newborn based on an international expert Delphi consensus.

The study aimed to develop structured, expert-based clinical guidance on the prenatal and postnatal management of hemolytic disease of the fetus and newborn. A Delphi procedure was conducted among an international panel of experts in fetal medicine, neonatology, and hematology. Experts were selected based on their expertise, relevant publications, and affiliations.

Neonatal/perinatal diagnosis of hemolysis using ETCOc.

Hemolysis is a pathological shortening of the red blood cell lifespan. When hemolysis occurs in a neonate, hazardous hyperbilirubinemia and severe anemia could result. Hemolysis can be diagnosed, and its severity quantified, by the non-invasive measurement of carbon monoxide (CO) in exhaled breath.

Design of a Phase 3, Global, Multicenter, Randomized, Placebo-Controlled, Double-Blind Study of Nipocalimab in Pregnancies at Risk for Severe Hemolytic Disease of the Fetus and Newborn.

Objective:  Nipocalimab is a neonatal fragment crystallizable (Fc) receptor (FcRn)-blocking monoclonal antibody that inhibits placental immunoglobulin G (IgG) transfer and lowers circulating maternal IgG levels. In an open-label, single-arm, phase 2 study, nipocalimab demonstrated evidence of safety and efficacy that support further investigation in a pivotal phase 3 trial of recurrent hemolytic disease of the fetus and newborn (HDFN). The phase 3 AZALEA study aims to evaluate the efficacy and safety of nipocalimab in a larger population at risk for severe HDFN, defined as HDFN associated with poor fetal outcomes or neonatal death.

Management of Red Cell Alloimmunization in Pregnancy.

Rhesus immune globulin has resulted in a marked decrease in the prevalence of RhD alloimmunization in pregnancy; however, antibody formation to other red cell antigens continues to occur. Evaluation for the presence of anti-red cell antibodies should be routinely undertaken at the first prenatal visit. If anti-red cell antibodies are detected, consideration of a consultation or referral to a maternal-fetal medicine specialist with experience in the monitoring and treatment of these patients is warranted.

Nipocalimab in Early-Onset Severe Hemolytic Disease of the Fetus and Newborn.

Background: In early-onset severe hemolytic disease of the fetus and newborn (HDFN), transplacental transfer of maternal antierythrocyte IgG alloantibodies causes fetal anemia that leads to the use of high-risk intrauterine transfusions in order to avoid fetal hydrops and fetal death. Nipocalimab, an anti-neonatal Fc receptor blocker, inhibits transplacental IgG transfer and lowers maternal IgG levels.

Methods: In an international, open-label, single-group, phase 2 study, we assessed treatment with intravenous nipocalimab (30 or 45 mg per kilogram of body weight per week) administered from 14 to 35 weeks' gestation in participants with pregnancies at high risk for recurrent early-onset severe HDFN.

Cell-Free DNA Analysis for the Determination of Fetal Red Blood Cell Antigen Genotype in Individuals With Alloimmunized Pregnancies.

Objective: To evaluate the accuracy of next-generation sequencing-based quantitative cell-free DNA analysis for fetal antigen genotyping in individuals with alloimmunized pregnancies undergoing clinical testing in practices across the United States as early as 10 weeks of gestation, with the objective of identifying individuals with pregnancies at risk for hemolytic disease of the fetus and newborn and guiding management.

Methods: This prospective cohort study included patients with alloimmunized pregnancies undergoing clinical fetal antigen cell-free DNA analysis between 10 0/7 and 37 0/7 weeks of gestation at 120 clinical sites. Both the pregnant person with the alloimmunized pregnancy and the neonates resulting from the pregnancies were included.

Hemoglobin Electrophoresis versus Kleihauer-Betke to Determine Bone Marrow Suppression in Fetuses Undergoing Intrauterine Transfusion.

Objective:  Mainstay therapy for fetuses affected by maternal red cell alloimmunization is serial intrauterine transfusion (IUT). Testing to determine when fetal red cells have been replaced with donor cells historically involves the use of the Kleihauer-Betke (KB) test. Hemoglobin (Hgb) electrophoresis testing may be more rapid with a reduced cost of analysis.

Receipt of RhD-positive whole blood for life-threatening bleeding in female children: A survey in alloimmunized mothers regarding minimum acceptable survival benefit relative to risk of maternal alloimmunization to anti-D.

Background: Low-titer group O whole blood (LTOWB) for treatment of hemorrhagic shock sometimes necessitates transfusion of RhD-positive units due to short supply of RhD-negative LTOWB. Practitioners must choose between using RhD-positive LTOWB when RhD-negative is unavailable against the risk to a female of childbearing potential of becoming RhD-alloimmunized, risking hemolytic disease of the fetus and newborn (HDFN) in future children, or using component therapy with RhD-negative red cells. This survey asked females with a history of red blood cell (RBC) alloimmunization about their risk tolerance of RhD alloimmunization compared to the potential for improved survival following transfusion of RhD-positive blood for an injured RhD negative female child.

Erythrokinetic mechanism(s) causing the "late anemia" of hemolytic disease of the fetus and newborn.

A transfusion-requiring "late anemia" can complicate the management of neonates convalescing from hemolytic disease of the fetus and newborn (HDFN). This anemia can occur in any neonate after HDFN but is particularly prominent in those who received intrauterine transfusions and/or double-volume exchange transfusions. Various reports describe this condition as occurring based on ongoing hemolysis, either due to passive transfer of alloantibody through breast milk or persistence of antibody not removed by exchange transfusion.

The Special Delivery Unit: A Novel Concept for Mother-Baby Continuity for Major Fetal Abnormalities.

Objective: This article describes the experience in the planning and development of a special delivery unit (SDU) at our free-standing children's hospital in Austin, Texas.

Study Design: Description of various aspects of the development of the SDU. In addition, telephone surveys were obtained from five other institutions regarding the planning and current status of their SDUs.

Live birth prevalence of hemolytic disease of the fetus and newborn in the United States from 1996 to 2010.

Background: Hemolytic disease of the fetus and newborn (HDFN) is mediated by maternal alloantibodies, a consequence of immune sensitization during pregnancy with maternal-fetal incompatibility with ABO, Rhesus factor (Rh), and/or other red blood cell antigens. RhD, Kell, and other non-ABO alloantibodies are the primary cause of moderate to severe HDFN, whereas ABO HDFN is typically mild. HDFN live birth prevalence owing to Rh alloimmunization among newborns in the United States was last estimated to be 106 per 100,000 births in 1986.

Open and endoscopic fetal myelomeningocele surgeries display similar in-hospital safety profiles in a large, multi-institutional database.

Background: Open intrauterine fetal myelomeningocele repair has demonstrated decreased ventriculoperitoneal shunting and improved motor outcomes despite maternal and fetal risks. Few data directly compare the safety of open vs endoscopic approaches.

Objective: This study aimed to analyze in-hospital maternal and fetal outcomes of pregnant patients undergoing open vs endoscopic fetal myelomeningocele repair using a large, multi-center database.

Immunomodulation for early-onset haemolytic disease of the fetus/newborn: Can we delay the need for intrauterine transfusions?

When cases of severe fetal anaemia due to maternal red-cell alloimmunization present in the early second trimester, standard treatment with intrauterine transfusion often results in fetal loss. The report by Vlachodimitropoulou et al. offers new insight into the use of maternal intravenous immune globulin to delay the need for intrauterine transfusion.