Third trimester amniocentesis for diagnosis of inherited bleeding disorders prior to delivery

Insights into the Molecular Genetic of Hemophilia A and Hemophilia B: The Relevance of Genetic Testing in Routine Clinical Practice

Hemophilia A and hemophilia B are rare congenital, recessive X-linked disorders caused by lack or deficiency of clotting factor VIII (FVIII) or IX (FIX), respectively. The severity of the disease depends on the reduction of coagulation FVIII or FIX activity levels, which is determined by the type of the pathogenic variants in the genes encoding the two factors (F8 and F9, respectively). Molecular genetic analysis is widely applied in inherited bleeding disorders. The outcome of genetic analysis allows genetic counseling of affected families and helps find a link between the genotype and the phenotype. Genetic analysis in hemophilia has tremendously improved in the last decades. Many new techniques and modifications as well as analysis softwares became available, which made the genetic analysis and interpretation of the data faster and more accurate. Advances in genetic variant detection strategies facilitate identification of the causal variants in up to 97% of patients. In this review, we discuss the milestones in genetic analysis of hemophilia and highlight the importance of identification of the causative genetic variants for genetic counseling and particularly for the interpretation of the clinical presentation of hemophilia patients.

Pregnancy in special populations: challenges and solutions practical aspects of managing von Willebrand disease in pregnancy

Pregnancy and childbirth pose an important hemostatic challenge for women with von Willebrand disease (VWD) and can be associated with an increased risk of maternal and neonatal bleeding complications. VWD is a genetically and clinically heterogeneous bleeding disorder caused by a deficiency or an abnormality in the function of von Willebrand factor. Understanding inheritance pattern, hemostatic response to pregnancy, and response to treatment is essential for provision of individualized obstetric care and optimal outcome. A multidisciplinary approach to management with a close liaison between the obstetric team and the hemophilia treatment center is required for continuity of care from preconception counseling through to antenatal, peripartum, and postpartum care. Delivery plan must be coordinated by the multidisciplinary team and include decisions on place and mode of delivery, implementation of safe analgesia/anesthesia, and peripartum hemostasis. In this clinical case-based review, we aim to deliver evidence-based practical guidance for challenges encountered during pregnancy and management of childbirth and puerperium.

European principles of care for women and girls with inherited bleeding disorders

INTRODUCTION

Despite increasing awareness of issues faced by women and girls with inherited BDs (WGBD), standards of care are lacking, with disparities in diagnosis and treatment for WGBD across Europe. We aimed to develop practical principles of care (PoC) to promote standardization of care for WGBD within European Haemophilia Treatment and Comprehensive Care Centres (HTC/CCCs).

METHODS

The co-creation process, supported by the European Association for Haemophilia and Allied Disorders, consisted of four multidisciplinary meetings with health care providers (HCPs) experienced in WGBD care, and European Haemophilia Consortium representatives, combined with broad patient and HCP consultations in the European haemophilia community. Relevant medical societies outside Europe were contacted for confirmation.

RESULTS

We developed ten PoC for WGBD, stressing the importance and benefits of a centralized, multidisciplinary, comprehensive, family-centred approach to support and manage WGBD during all life stages. These PoC emphasise the right to equitable access and quality of care for all people with BDs, irrespective of gender. Multiple medical societies outside Europe also confirmed their support for endorsement.

CONCLUSIONS

Ten PoC for WGBD evolved from an iterative process among stakeholders, supported by relevant medical societies worldwide. These PoC can serve as a benchmark for diagnosis and comprehensive multidisciplinary management of WGBD, and improve awareness of their unique challenges. They offer a framework to guide HTC/CCCs in providing equitable care for all WGBD, both in their own services and in other healthcare settings. Implementation of these principles aims to positively impact the health, wellbeing and quality of life for WGBD.

Haemophilia

Haemophilia A and B are rare congenital, recessive X-linked disorders caused by lack or deficiency of clotting factor VIII (FVIII) or IX (FIX), respectively. The severity of the disease depends on the reduction of levels of FVIII or FIX, which are determined by the type of the causative mutation in the genes encoding the factors (F8 and F9, respectively). The hallmark clinical characteristic, especially in untreated severe forms, is bleeding (spontaneous or after trauma) into major joints such as ankles, knees and elbows, which can result in the development of arthropathy. Intracranial bleeds and bleeds into internal organs may be life-threatening. The median life expectancy was ~30 years until the 1960s, but improved understanding of the disorder and development of efficacious therapy based on prophylactic replacement of the missing factor has caused a paradigm shift, and today individuals with haemophilia can look forward to a virtually normal life expectancy and quality of life. Nevertheless, the potential development of inhibitory antibodies to infused factor is still a major hurdle to overcome in a substantial proportion of patients. Finally, gene therapy for both types of haemophilia has progressed remarkably and could soon become a reality.

The experiences and attitudes of hemophilia carriers around pregnancy: A qualitative systematic review

BACKGROUND

Hemophilia carriers (HCs) face specific psychosocial challenges related to pregnancy, caused by their inherited bleeding disorder. Optimal support from healthcare providers can only be realized by exploring medical and psychological healthcare requirements.

OBJECTIVE

To review all published evidence on the experiences and attitudes of HCs regarding reproductive decision-making, prenatal diagnosis, pregnancy, childbirth, and puerperium to provide an accessible overview of this information for health care providers.

STUDY SELECTION

Cochrane library, PubMed/MEDLINE, EMBASE, CINAHL, and PsycINFO were searched for original qualitative data. Two authors performed study selection, risk-of-bias assessment, data extraction, and data analysis through meta-summary. The extracted themes were discussed within the research team.

FINDINGS

Fifteen studies with an overall moderate quality were included. The following findings were identified: (a) Quality of life of family members with hemophilia influences reproductive decision-making; (b) Genetic counselling is generally considered useful; (c) The development of a specialized carrier clinic is considered valuable; (d) HCs describe prenatal diagnosis as beneficial yet psychosocially challenging; and (e) noninvasive prenatal diagnosis and preimplantation genetic diagnosis are predominantly considered beneficial. These findings are limited by the overall moderate quality of included studies and the possibly partly outdated results in the current era of hemophilia treatment.

CONCLUSIONS

Available qualitative literature on HCs around pregnancy focuses on genetic counselling and prenatal diagnosis. Future studies are needed on the experiences and needs of HCs through pregnancy and puerperium as well as in light of emerging hemophilia diagnosis and treatment options.

Role of late amniocentesis in the era of modern genomic technologies

OBJECTIVE

Traditionally, amniocentesis is performed between 17 and 23 weeks of gestation. This enables decisions regarding the course of pregnancy to be made before viability. Less frequently, amniocentesis is performed in the third trimester. Advanced genomic technologies such as chromosomal microarray analysis (CMA) provide more detailed information about the fetus compared with traditional G-banded chromosomal analysis. The aim of this study was to assess the indications for and safety of late amniocentesis, genetic-test results (especially in the context of CMA technology) and outcome of pregnancies that underwent the procedure after 24 weeks.

METHODS

Medical records were analyzed retrospectively of all women in whom amniocentesis was performed at a gestational age of 24 + 0 to 38 + 6 weeks, at Hadassah Medical Center, between June 2013 and March 2017. Parameters investigated included indications for late amniocentesis, complications, CMA results and pregnancy outcome.

RESULTS

During the study period, 291 women (303 fetuses, 277 singleton and 14 twin pregnancies; in two twin pairs, one fetus was terminated before amniocentesis) underwent late amniocentesis. CMA was performed in all instances of amniocentesis. The most frequent indication was abnormal sonographic finding(s) (204/303 fetuses, 67%). Preterm delivery occurred in 1.7% and 5.1% of pregnancies within the first week and within 1 month following the procedure, respectively. Aneuploidy was detected in nine (3%) fetuses and nine (3%) others had a pathogenic/likely pathogenic copy number variant, suggesting that CMA doubled the diagnostic yield of traditional karyotyping. Maximal diagnostic yield (17.5%) was achieved for the subgroup of fetuses referred with abnormal sonographic findings in two or more fetal anatomical systems. Variants of uncertain significance or susceptibility loci were found in another nine (3%) fetuses.

CONCLUSIONS

In pregnancies undergoing late amniocentesis, CMA increased detection rates of fetal abnormalities and had a shorter turnaround time compared with traditional chromosomal analysis; therefore, late amniocentesis may serve as a helpful tool for detecting fetal abnormalities or reassuring parents following late-appearing abnormal sonographic findings. However, CMA may expose findings of uncertain significance, about which the couple should be precounseled. The procedure appears to be safe. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

A Practical Guide to the Management of the Fetus and Newborn With Hemophilia

Newborns with hemophilia are at risk of intracranial hemorrhage, extracranial hemorrhage, and other bleeding complications. The safe delivery of a healthy newborn with hemophilia is a complex process that can begin even before conception, and continues throughout pregnancy, birth, and the newborn period. This process involves the expectant parents and a wide variety of health-care professionals: genetic counselors, obstetricians, neonatologists, pediatricians, radiologists, adult and pediatric hematologists, and nurses with expertise in hemophilia. Because of this multidisciplinary complexity, the relative rarity of births of newborns with hemophilia, and the lack of high-quality evidence to inform decisions, there is considerable variation in practice in this area. We present a comprehensive multidisciplinary approach, from preconception counseling to discharge planning after birth, and describe available options for management decisions. We highlight a number of areas of important uncertainty and controversy, including the preferred mode of delivery, the appropriate use and timing of neuroimaging tests, and the appropriate use of clotting factor concentrates in the newborn period. While the approach presented here will aid clinicians in planning and providing care, further research is required to optimize the care of newborns with hemophilia.

Prenatal diagnosis in rare bleeding disorders-An unresolved issue?

Intracranial haemorrhage (ICH) is the most dreadful complication, and the main cause of death among patients with rare bleeding disorders (RBD) and prenatal diagnosis (PND) is a preventative lifesaving program. A total of 39 PNDs were reported in the literature through a search on PubMed, EMBASE, SCOPUS and Web of Science databases, most often for congenital factor (F) XIII and FVII deficiencies and rarely in FX, FV deficiencies and afibrinogenemia. The main cause to request a PND is ICH and related morbidity and mortality. Different molecular methods including direct sequencing and linkage analysis as well as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for a specific mutation are the most common used methods for PND, while factor assay and combination of molecular and factor assay also were used. In this research, 7 severely affected foetuses were identified during PND including 3 foetuses with FXIII deficiency, 3 with FVII deficiency and 1 with FX deficiency. Out of these 7 cases, intrauterine ICH occurred in 1 case with FXIII deficiency, 1 was electively aborted and 1 case with severe FVII deficiency received intrauterine factor transfusion. Postdelivery ICH was reported for 1 patient with severe FVII deficiency within the first month of life. All other pregnancies were uneventful.

Update on inherited disorders of haemostasis and pregnancy

Inherited bleeding disorders have the potential to cause bleeding complications during pregnancy, childbirth and the postpartum period as well as effect fetal outcomes. There is an evolving understanding of the need for specialised and individualised care for affected women during these times. The aim for each patient is to estimate the risk to mother, fetus and neonate; to implement measures to minimise these risks; and to anticipate complications and develop contingencies for these scenarios. This includes accurate diagnosis, preconceptual care, prenatal diagnostic options, antenatal care, delivery and postpartum care as well as care of an affected neonate. An understanding of the physiologic haemostatic changes associated with pregnancy as well as the scope of defects, inheritance and management of inherited bleeding disorders is paramount when caring for these women. Collaborative and prospective management in conjunction with haematology services underpins the approach advocated. This review draws on the available literature, and outlines the principles of care for women with inherited bleeding disorders before, during and after pregnancy, as well as their babies, based on both available data and collective clinical experience.

Hemophilia B: molecular pathogenesis and mutation analysis

Hemophilia B is an X-chromosome-linked inherited bleeding disorder primarily affecting males, but those carrier females with reduced factor IX activity (FIX:C) levels may also experience some bleeding. Genetic analysis has been undertaken for hemophilia B since the mid-1980s, through linkage analysis to track inheritance of an affected allele, and to enable determination of the familial mutation. Mutation analysis using PCR and Sanger sequencing along with dosage analysis for detection of large deletions/duplications enables mutation detection in > 97% of patients with hemophilia B. The risk of the development of inhibitory antibodies, which are reported in ~ 2% of patients with hemophilia B, can be predicted, especially in patients with large deletions, and these individuals are also at risk of anaphylaxis, and nephrotic syndrome if they receive immune tolerance induction. Inhibitors also occur in patients with nonsense mutations, occasionally in patients with small insertions/deletions or splice mutations, and rarely in patients with missense mutations (p.Gln237Lys and p.Gln241His). Hemophilia B results from several different mechanisms, and those associated with hemophilia B Leyden, ribosome readthrough of nonsense mutations and apparently 'silent' changes that do not alter amino acid coding are explored. Large databases of genetic variants in healthy individuals and patients with a range of disorders, including hemophilia B, are yielding useful information on sequence variant frequency to help establish possible variant pathogenicity, and a growing range of algorithms are available to help predict pathogenicity for previously unreported variants.