Autoimmune Congenital Heart Block Research Articles

Reversible complete atrioventricular block in a neonate with maternal anti-Sjögren's syndrome-associated antibody: atypical phenotype of autoimmune congenital heart block.

The fetus of anti-Sjögren's syndrome-associated antibody-positive mother developed complete atrioventricular block at 39 weeks of gestation and required urgent ventricular pacing after birth. Unexpectedly, the patient recovered from the atrioventricular block within a few days. Fraction analysis of maternal anti-Sjögren's syndrome-associated antibody revealed positivity for isolated anti-Ro/SSA 60 kDa antibody, which is abnormal as most patients with complete atrioventricular block present with anti-Ro/SSA52 kDa positivity, which may indicate a potentially atypical late and reversible manifestation of an autoimmune congenital atrioventricular block in this patient.

Autoimmune Congenital Complete Heart Block: How Late Can It Occur?

Objective Maternal anti-Ro (SSA) and/or anti-La (SSB) antibodies are a risk factor for congenital complete heart block (CHB). Because detailed analysis of the incidence of CHB after 24 weeks of gestational age (GA) is lacking, we aimed to ascertain the risk of "later-onset" CHB among offspring of SSA/SSB-positive mothers in the published literature. Study Design Using search terms "neonatal lupus heart block" and "autoimmune congenital heart block" on PubMed and Ovid, we gathered prospective studies of SSA/SSB-positive mothers with fetal echo surveillance starting from before CHB diagnosis and retrospective cases of fetal CHB diagnosis after 24 weeks of GA (if there was prior normal heart rate) or after birth. Results Ten prospective studies included 1,248 SSA/SSB-positive pregnancies with 24 cases of CHB diagnosed during pregnancy (1.9%). Among these, three (12.5%) were after 24 weeks-at weeks 25, 26, and 28. Our retrospective studies revealed 50 patients with CHB diagnosis in late fetal life and neonatal period and 34 in the nonneonatal childhood period. An additional four cases were diagnosed after age 18 years. Conclusion Later-onset autoimmune CHB in offspring of SSA/SSB-positive mothers does occur. Our analysis suggests that prenatal surveillance should continue beyond 24 weeks of GA but is limited by inconsistent published surveillance data.

Fetal screening and prevention of autoimmune heart block: What about the French cardiofetalist practice?

Fetal autoimmune congenital heart block (CHB) is often diagnosed at an irreversible stage with a high related morbi-mortality. Cardiologic screening and preventive therapy during pregnancy are still not consensual. The objective of this study was to evaluate the prenatal follow up and management of pregnant women with anti-Ro/Sjögren's syndrome antigen A (SSA) or anti-La/Sjögren's syndrome antigen B (SSB) antibodies, among the French community of fetal cardiologists. Nationwide digital questionnaires were sent to the French community of fetal cardiologists. Fetal cardiologists were asked about their management, follow up, preventive care and curative therapy used in immune pregnancies with a CHB risk. Among the 45 fetal cardiologists surveyed, 38 (84%) accepted to respond. Regarding the follow-up of immune pregnancies, 97% of fetal cardiologists use to perform a dedicated systematic fetal echocardiography, twice a month, from 18 to 26 weeks of gestation. A more frequent and longer screening is usually performed for women who experienced a previous fetal immune CHB. 38% of fetal cardiologists would also propose a self-monitoring of fetal heart rate to complete their regular follow up. Regarding preventive therapy of fetal autoimmune CHB, the use of Hydroxychloroquine is recommended by 48% of fetal cardiologists. 43% would use bethametasone in case of a 1st and 2nd degree CHD and 24% in case of a 3rd CHD. 16% would also prescribe beta-mimetic drugs in case of 3rd atrio-ventricular block with fetal bradycardia. Treatments are usually introduced after a shared decision with internal medicine physicians and obstetricians. Most French fetal cardiologists perform a regular systematic follow-up in immune pregnancies with a CHB risk. This screening could be associated with a fetal heart rate self-monitoring at home. Preventive and curative therapies of CHD are still not consensual and rarely used, which is in line with their poor published efficacy.

Short and long-term outcomes of children with autoimmune congenital heart block treated with a combined maternal-neonatal therapy. A comparison study.

The short and long-term outcomes of children with anti-Ro/La-related congenital heart block treated with a combined maternal-neonatal therapy protocol were compared with those of controls treated with other therapies. Sixteen mothers were treated during pregnancy with a therapy consisting of daily oral fluorinated steroids, weekly plasma exchange and fortnightly intravenous immunoglobulins and their neonates with intravenous immunoglobulins (study group); 19 mothers were treated with fluorinated steroids alone or associated to intravenous immunoglobulins or plasma exchange (control group). The combined-therapy children showed a significantly lower progression rate from 2nd to 3rd degree block at birth, a significant increase in heart rate at birth and a significantly lower number of pacemaker implants during post-natal follow-up with respect to those treated with the other therapies. The combined therapy produced better short and long term outcomes with respect to the other therapies studied.

Health Outcomes of 215 Mothers of Children With Autoimmune Congenital Heart Block: Analysis of the French Neonatal Lupus Syndrome Registry.

Transplacental passage of maternal anti-SSA and anti-SSB antibodies, potentially associated with maternal autoimmune diseases, can cause neonatal lupus syndrome. Given the paucity of data in this setting, we report short- and long-term outcomes of mothers of offspring with congenital heart block (CHB). This retrospective study included anti-SSA/SSB antibody-positive mothers of fetuses with high-degree CHB and focused on their health status before pregnancy, at CHB diagnosis, and thereafter. We analyzed 215 women with at least 1 pregnancy with CHB. Prior to this diagnosis, only 52 (24%) mothers had been diagnosed with an autoimmune disease, mainly systemic lupus erythematosus (SLE; n = 26, 12%) and Sjögren syndrome (SS; n = 16, 7%). Six more were diagnosed with an autoimmune disease during the index pregnancy. Of the 157 mothers (73%) with no such diagnosis at childbirth, 77 (49%) developed one after a median follow-up of 11 years (range: 21 days to 54 years). By the end of follow-up, 135 women (63%) had an autoimmune disease diagnosis, mainly SLE (n = 54, 25%) and SS (n = 72, 33%). Three patients with SLE had renal involvement, and only 6 (3%) had required an immunosuppressive drug at any point. The symptoms best predicting autoimmune disease development were arthralgia and myalgia (P < 0.001), dry syndrome (P = 0.01), and parotid swelling (P = 0.05). One-quarter of the patients had an autoimmune disease diagnosis at the time of the fetal CHB diagnosis. Nearly half of those without an initial diagnosis progressed during follow-up, most without severe manifestations. Severe diseases such as lupus nephritis were rarely seen, and immunosuppressive drugs were rarely required.

Recurrent Congenital Heart Block Due to Maternal Anti-Ro Antibodies: Successful Prevention of Poor Pregnancy Outcome with Hydroxychloroquine and Added Dexamethasone

Autoimmune Congenital Heart Block (CHB) is an immune-mediated disease caused by transplacental passage of maternal circulating anti-Ro/SSA and anti-La/SSB antibodies which can bind to fetal cardiac tissue, damaging conduction tissues by inflammation and fibrosis. Approximately 2% of pregnancies with positive anti-Ro antibodies will be complicated by fetal atrioventricular block and the risk of recurrence in subsequent pregnancies is 10 times higher. We report a case of a clinically asymptomatic patient diagnosed with anti-Ro antibodies who had two pregnancies complicated by CHB with different outcomes. Despite preventive treatment with hydroxychloroquine (HCQ) from 6 weeks of pregnancy onward, the fetus developed second to third degree CHB. Dexamethasone was added. The pregnancy evolved to near-term with persistent intermittent CHB. It is not clear how pregnancies with recurrent fetal CHB despite prophylaxis with HCQ should be managed and there is a need for controlled studies to answer the remaining questions in relation to this subject.

Successful perinatal management and pacemaker stimulation during the first hour of life in a 1.6 kg newborn with autoimmune congenital complete heart block diagnosed prenatally

Successful perinatal management and pacemaker stimulation during the first hour of life in a 1.6 kg newborn with autoimmune congenital complete heart block diagnosed prenatally

Interferons and innate immune activation in autoimmune congenital heart block.

Autoimmune congenital heart block (CHB) may develop in foetuses of women carrying anti-Ro/SSA and La/SSB autoantibodies and is characterized by disruption of signal conduction at the atrioventricular (AV) node, resulting in partial or complete AV block. If not fatal in utero, complete CHB typically requires lifelong cardiac pacing. No treatment has so far been unequivocally demonstrated to prevent or treat autoimmune CHB, and the relatively low incidence (1%-5%) and recurrence (12%-16%) rates of second/third-degree AV block add to the complexity of managing pregnancies in women with anti-Ro/La antibodies. Altogether, a better understanding of events leading to development of autoimmune CHB is needed to improve surveillance and treatment strategies. In the past decade, studies have started to look beyond the role of maternal autoantibodies in disease pathogenesis to assess other contributing factors such as foetal genetics and, more recently, immune responses in foetuses and neonates of anti-Ro/La antibody-positive women. In this review, we provide an update on the epidemiology, clinical presentation and current treatment approaches of autoimmune CHB, summarize the previously proposed pathogenic mechanisms implicating maternal autoantibodies, and discuss the recent findings of type I interferon (IFN) and innate immune activation in foetuses with autoimmune CHB and in neonates of anti-Ro/La antibody-positive mothers, and how these may contribute to autoimmune CHB pathogenesis.

Autoimmune Congenital Heart Block: A Review of Biomarkers and Management of Pregnancy.

Autoimmune Congenital Heart Block (CHB) is an immune-mediated disease due to transplacental passage of circulating anti-Ro/SSA and anti-La/SSB autoantibodies. It occurs in 2% of anti-Ro/SSA-exposed pregnancies, and recurrence rate is nine times higher in subsequent pregnancies. Aim of this review is to identify biomarkers of CHB and treatment strategies. The Ro-system is constituted by two polypeptides targeted by the anti-Ro52 and anti-Ro60 autoantibodies. The central portion of Ro52 (p200), more than the full amino-acid sequence of Ro-52, is recognized to be the fine specificity of anti-Ro associated to the highest risk of cardiac damage. If anti-p200 antibody should be tested, as biomarker of CHB, over standard commercial ELISAs is still debated. Recent studies indicate that type I-Interferon (IFN) can activate fibroblasts in fetal heart. In the mother the anti-Ro/La antibodies activate the type I IFN-signature, and maternal IFN-regulated genes correlate with a similar neonatal IFN-gene expression. Evaluation of maternal IFN-signature could be used as novel biomarker of CHB. The measurement of “mechanical” PR interval with weekly fetal echocardiogram (ECHO) from 16 to at least 24 weeks of gestation is strongly recommended for CHB prenatal diagnosis. However, ECHO screening presents some limitations due to difficult identification of first-degree block and possible occurrence of a complete block from a normal rhythm in few days. Maternal administration of Hydroxychloroquine from the tenth week of gestation, modulating toll-like receptor and autoantibody-dependent type I IFN activation on the fetus, has an important role in preventing CHB in pregnant women with high risk for recurrent CHB.

Maternal autoantibodies and congenital heart block

Introduction: Autoimmune congenital heart block (CHB) of the fetus is the severest manifestation of neonatal lupus, and it is damage of AV node of the fetus that is the root cause problem. Congenital heart block is mainly associated with maternal Systemic Lupus Erythematous (SLE) and anti-Ro and anti-La positive maternal status. This observational study was done to know the incidence of congenital heart block in patients of Systemic Lupus Erythematous who had ANA, anti-Ro/SSA and anti-La/ SSB levels positive. Materials and Methods: A prospective observational study was done in a University teaching hospital of North India (Banaras Hindu University). The study duration was between January 2014 to December 2016 and 9 cases of SLE were identified and diagnosed. All these patients were tested for ANA, anti-Ro/SSA and anti- La/SSB antibodies, were found to be positive. Three fetuses had confirmed fetal heart rate abnormalities/congenital heart block. Our neonatologist treated fetuses with heart block as per their protocols. Mothers were counseled regarding recurrence of congenital heart block in the next pregnancy. Results: All patients of SLE were positive for ANA, and had anti-Ro/ SSA- and anti-La/SSB-positive status. Three fetuses/neonate had congenital heart block, and one fetus required pacemaker after delivery. Conclusions: Delivery should be organized in tertiary referral center and with multidisciplinary care. Treatment with pacemaker insertion is life saving. These fetuses can be salvaged if they are given proper care although couple should be explained the prognosis. Keyword: Systemic Lupus Erythematous, Autoantibodies, Congenital heart block, Anti-Ro, anti-La, ANA, DSDNA, Lupus nephritis.

Autoimmune-mediated congenital heart block

Autoimmune-mediated congenital heart block (CHB) is a severe manifestation of neonatal lupus in which conduction tissues of the fetal heart are damaged. This occurs due to passive transference of maternal anti-SSA/Ro and anti-SSB/La autoantibodies and subsequent inflammation and fibrosis of the atrioventricular (AV) node. Notably, the disease manifests after the fetal heart has structurally developed, ruling out other anatomical abnormalities that could otherwise contribute to the block of conduction. Complete AV block is irreversible and the most common manifestation of CHB, although other cardiac complications such as endocardial fibroelastosis (EFE), dilated cardiomyopathy, and valvular insufficiency have been observed. In this review, we detail the classification, prevalence, pathogenesis, and clinical management recommendations for autoimmune CHB.

Therapeutic apheresis during pregnancy: A single center experience

IntroductionTherapeutic apheresis (TA) represents a treatment option for pre-existing conditions or diseases occurring during gestation. Although pregnancy is not a contraindication per se, due to the lack of evidence-based guidelines and presumed risk of maternal/fetal adverse events there is a general resistance to its application. Material and methodsBetween January 2005 and August 2017, at the Apheresis Unit of the University Hospital of Padua 936 TA procedures were performed during 57 pregnancies in 48 patients: 813 Plasma Exchange sessions, 119 Immunoadsorptions, 4 Red Blood Cell exchanges. The treated disease were as follows: antiphospholipid syndrome (18 patients), autoimmune congenital heart block (18), myasthenia gravis (3), Rh alloimmunization (2), systemic sclerosis (1), suspected autoimmune encephalitis (1), severe hypertriglyceridaemia (1), post partum hemolytic-uremic syndrome (1), sickle cell disease (1), lupus nephritis (1) and thrombotic thrombocytopenic purpura (1). ResultsIn the time period considered the apheresis sessions applied to pregnant women were 7.1% of the total (n = 13.251). The median age at the first treatment was 33 years. The median week of gestation (WG) at the beginning of treatments was 21. Twenty (2.1%) sessions were complicated by adverse events, none requiring or prolonging hospitalization. There were 50 live births, 5 spontaneous abortions and 2 voluntary terminations of pregnancy. Median WG at delivery was 35 and caesarean section was performed in 46 cases. ConclusionsOur data showed that TA in pregnancy is well tolerated. Close collaboration between clinician, obstetrician and TA specialist is crucial to ensure a good outcome of high-risk pregnancies.

Benefits of fetal echocardiographic surveillance in pregnancies at risk of congenital heart block: single-center study of 212 anti-Ro52-positive pregnancies.

Assuming that autoimmune congenital heart block (CHB) is a progressive disease amenable to therapeutic modulation, we introduced a surveillance program for at-risk pregnancies with the dual aim of investigating if fetal atrioventricular block (AVB) could be detected and treated before becoming complete and irreversible, and to establish the incidence of AVB I, II and III in a large prospective cohort. This was a prospective study of 212 anti-Ro52 antibody-exposed pregnancies at risk of fetal AVB that were followed weekly between 18 and 24 weeks' gestation at our tertiary fetal cardiology center from 2000 to 2015. A 12-lead electrocardiogram (ECG) was recorded within 1 week after birth. Fetal Doppler atrioventricular (AV) intervals were converted to Z-scores using reference standard values derived from normal pregnancies. Each fetus was represented by the average value of the two recordings, obtained at two consecutive visits, which resulted in the longest AV interval. AV interval values were classified into normal AV conduction (Z-score ≤ 2.0) and three levels of delayed AV conduction: Z-score > 2.0 and ≤ 3.0, Z-score > 3.0 and ≤ 4.0, and Z-score > 4.0. AVB II or III developed in 6/204 (2.9%) pregnancies without a CHB history and 1/8 (12.5%) of those with a CHB history. AV intervals > 2 and ≤ 3, > 3 and ≤ 4, and > 4 were detected in 16.0%, 7.5% and 2.8% of cases, respectively, and were related to the PR interval on 185 available ECGs. Three of the five cases with AVB III and one of two cases with 2:1 AVB II developed within 1 week of AV interval Z-score of 1.0, 1.9, 2.8 and 1.9, respectively. Transplacental treatment with betamethasone was associated with restoration of 1:1 AV conduction in the two fetuses with AVB II, with a better long-term result (normal ECG vs AVB I or II) observed in the case in which treatment was started within 1 week after AVB developed. Betamethasone treatment did not reverse AVB III, although a temporary effect on AV conduction was observed in 1/5 cases. Notably, the three cases in which treatment was started within 1 week after AVB III development responded with a higher ventricular rate than the other two cases and did not require pacemaker implantation until a later age (2-5 years vs 1.5-2 months). Fetal AV interval is a poor predictor of CHB progression, but CHB surveillance still allows detection of fetuses with AVB II or III shortly after its development, allowing for timely treatment initiation and potentially better outcome. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Siglec-1 Macrophages and the Contribution of IFN to the Development of Autoimmune Congenital Heart Block.

Given that diseases associated with anti-SSA/Ro autoantibodies, such as systemic lupus erythematosus and Sjögren syndrome, are linked with an upregulation of IFN and type I IFN-stimulated genes, including sialic acid-binding Ig-like lectin 1 (Siglec-1), a receptor on monocytes/macrophages, recent attention has focused on a potential role for IFN and IFN-stimulated genes in the pathogenesis of congenital heart block (CHB). Accordingly, three approaches were leveraged to address the association of IFN, IFN-stimulated genes, and the phenotype of macrophages in affected fetal cardiac tissue: 1) cultured healthy human macrophages transfected with hY3, an anti-SSA/Ro-associated ssRNA, 2) RNA isolated from freshly sorted human leukocytes/macrophages after Langendorff perfusion of three fetal hearts dying with CHB and three healthy gestational age-matched hearts, and 3) autopsy tissue from three additional human CHB hearts and one healthy heart. TLR ligation of macrophages with hY3 led to the upregulation of a panel of IFN transcripts, including SIGLEC1, a result corroborated using quantitative PCR. Using independent and agnostic bioinformatics approaches, CD45+CD11c+ and CD45+CD11c- human leukocytes flow sorted from the CHB hearts highly expressed type I IFN response genes inclusive of SIGLEC1. Furthermore, Siglec-1 expression was identified in the septal region of several affected fetal hearts. These data now provide a link between IFN, IFN-stimulated genes, and the inflammatory and possibly fibrosing components of CHB, positioning Siglec-1-positive macrophages as integral to the process.

Autoimmune-associated Congenital Heart Block: A New Insight in Fetal Life.

Objective:Congenital heart block (CHB) is a rare but life-threatening disorder. More than half of CHB cases are associated with maternal autoimmune, which are termed as autoimmune-associated CHB. This review summarized the recent research findings in understanding autoimmune-associated CHB, discussed the current diagnostic approaches and management strategies, and summarized the problems and future directions for this disorder.Data Sources:We retrieved the articles published in English from the PubMed database up to January 2017, using the keywords including “Autoimmune-associated”, “Autoimmune-mediated”, and “Congenital heart block”.Study Selection:Articles about autoimmune-associated CHB were obtained and reviewed.Results:Observational studies consistently reported that transplacental maternal antibodies might recognize fetal or neonatal antigens in various tissues and result in immunological damages, but the molecular mechanisms underlying CHB pathogenesis still need illuminated. Multiple factors were involved in the process of atrioventricular block development and progression. While several susceptibility genes had been successfully defined, how these genes and their protein interact and impact each other remains to be explored. With currently available diagnostic tools, fetal ultrasound cardiography, and fetal magnetocardiography, most of CHB could be successfully diagnosed and comprehensively evaluated prenatally. The efficacy of current approaches for preventing the progression and recurrence of CHB and other autoimmune-mediated damages was still controversial.Conclusions:This review highlighted the relationships between autoimmune injuries and CHB and strengthened the importance of perinatal management and therapy for autoimmune-associated CHB.

Brief Report: Association of Natural Killer Cell Ligand Polymorphism HLA–C Asn80Lys With the Development of Anti‐SSA/Ro–Associated Congenital Heart Block

Fetal exposure to maternal anti-SSA/Ro antibodies is necessary but not sufficient for the development of autoimmune congenital heart block (CHB), suggesting that other factors, such as fetal genetic predisposition, are important. Given the previously described association between major histocompatibility complex alleles and CHB risk, we undertook the present study to test the hypothesis that a variant form of HLA-C Asn80Lys, which binds with high affinity to an inhibitory killer cell immunoglobulin-like receptor (KIR) and thus renders natural killer (NK) cells incapable of restricting inflammation, contributes to the development of CHB. Members of 192 pedigrees in the US and Europe (194 cases of CHB, 91 unaffected siblings, 152 fathers, 167 mothers) and 1,073 out-of-study controls were genotyped on the Immunochip single-nucleotide polymorphism microarray. Imputation was used to identify associations at HLA-C Asn80Lys (Asn, C1; Lys, C2) and KIR. Tests for association were performed using logistic regression. McNemar's test and the pedigree disequilibrium test (PDT) were used for matched analyses between affected and unaffected children. Compared with out-of-study controls of the same sex, the C2 allele was less frequent in the mothers (odds ratio [OR] 0.63, P = 0.0014) and more frequent in the fathers (OR 1.40, P = 0.0123), yielding a significant sex-by-C2 interaction (P = 0.0002). The C2 allele was more frequent in affected siblings than in unaffected siblings (OR 3.67, P = 0.0025), which was consistent with the PDT results (P = 0.016); these results were observed in both sexes and across the US and European cohorts. There was no difference in the frequency of the inhibitory KIR genotype (KIR AA) between affected and unaffected children (P = 0.55). These data establish C2 as a novel genetic risk factor associated with CHB. This observation supports a model in which fetuses with C2 ligand expression and maternal anti-SSA/Ro positivity may have impaired NK cell surveillance, resulting in unchecked cardiac inflammation and scarring.

Should we treat congenital heart block with fluorinated corticosteroids?

Abstract Cardiac involvement is the most severe manifestation of neonatal lupus. It is usually diagnosed as an advanced (second or third degree) atrio-ventricular (AV) congenital heart block (CHB) starting around 20 weeks of gestation. At this gestational time, a window of opportunity might exist, and fluorinated corticosteroids (FS) have been attempted as a therapeutic option. Unfortunately the quality of the studies is methodologically low, due to the retrospective design and to the rarity of autoimmune CHB. Some case reports and small case series basically suggested a possible utility of FS, mainly in the context of incomplete CHB, while larger observational retrospective studies did not find any efficacy of FS either on mortality, on the rate of pacemaker implantation, to reduce the degree of incomplete CHB or to reduce the development of cardiomyopathy. Of note the distinction between complete and incomplete AV block may be very difficult and time consuming in utero. Overall FS should not be recommended in CHB, but might be considered for a short time for a recent incomplete CHB.

High maternal expression of SIGLEC1 on monocytes as a surrogate marker of a type I interferon signature is a risk factor for the development of autoimmune congenital heart block

ObjectivesAutoimmune congenital heart block (CHB) is associated with placental transcytosis of maternal autoantibodies directed against Ro/SS-A and La/SS-B. However, only about 2% of children born to mothers with the respective...

Maternal autoantibody profiles at risk for autoimmune congenital heart block: a prospective study in high-risk patients

ObjectiveThis prospective study aimed to identify antibody profiles characterising mothers with fetuses developing congenital heart block (CHB) by comparing their antibody frequencies and levels with those in unaffected mothers.MethodsEighty-one consecutive...

Autoimmune congenital heart block: complex and unusual situations.

Autoimmune congenital heart block (ACHB) is an immune-mediated cardiac disease included among the manifestations collectively referred to as neonatal lupus. The placental transference of maternal Ro/La autoantibodies may damage the conduction tissues during fetal development leading to blocking of signal conduction at the atrioventricular (AV) node in an otherwise structurally normal heart. Irreversible complete AV block is the main cardiac manifestation of ACHB, but some babies may develop endocardial fibroelastosis, valvular insufficiency, and/or frank cardiomyopathies with significantly reduced cardiac function requiring transplant. The severity of ACHB is illustrated by a global mortality rate of 20% and pacemaker rates of at least 64%, often within the first year of life. This review analyses the main complex and/or unusual clinical situations associated with ACHB, including unusual maternal immunological profiles, infrequent maternal autoimmune diseases, cardiac damage unrelated to AV block, fetal invasive management, late complications after birth, risk of congenital heart block (CHB) in ovodonation and in vitro fertilization techniques, the role of maternal features other than autoimmunity, the influence of the birth order or the risk of CHB in twins and triplets.