Fetal magnetocardiography (fMCG) to monitor cardiac time intervals in fetuses at risk for isoimmune AV block

Fetal arrhythmias: Surveillance and management

Fetal arrhythmias warrant sophisticated surveillance and management, especially for the high-risk pregnancies. Clinically, fetal arrhythmias can be categorized into 3 types: premature contractions, tachyarrhythmias, and bradyarrhythmias. Fetal arrhythmias include electrocardiography, cardiotocography, echocardiography and magnetocardiography. Oxygen saturation monitoring can be an effective way of fetal surveillance for congenital complete AV block or SVT during labor. Genetic surveillance of fetal arrhythmias may facilitate the understanding of the mechanisms of the arrhythmias and provide theoretical basis for diagnosis and treatment. For fetal benign arrhythmias, usually no treatment but a close follow-up is need, while persistant fetal arrhythmias with congestive heart dysfunction or hydrops fetalis, intrauterine or postnatal treatments are required. The prognoses of fetal arrhythmias depend on the type and severity of fetal arrhythmias and the associated fetal conditions. Responses of fetal arrhythmias to individual treatments and clinical schemes are heterogeneous, and the prognoses are poor particularly under such circumstances.

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.

Controversies in the Management of Isolated Congenital Atrioventricular Block

Congenital atrioventricular block (CAVB) affects approximately 2% of fetuses of mothers with anti-Ro or anti-La antibodies, regardless of maternal rheumatologic symptoms. Anti-Ro and anti-La antibodies are antinuclear antibodies commonly found in autoimmune diseases. Congenital atrioventricular block is associated with a relatively high fetal morbidity and mortality, particularly more advanced degrees of block. There is significant controversy surrounding surveillance of anti-Ro/La-positive pregnancies and treatment of fetuses diagnosed with CAVB. Studies of dexamethasone in the treatment of CAVB have yielded conflicting results, with most suggesting only a limited potential benefit in first- and seconddegree CAVB and in cases complicated by fetal hydrops. Larger prospective studies are needed to further evaluate the efficacy of intravenous immunoglobulin in the treatment of CAVB and of intravenous immunoglobulin and hydroxychloroquine in the prevention of CAVB in fetuses of at-risk mothers. Surveillance and treatment regimens should be determined on a case-by-case basis, taking into consideration the degree of CAVB, costs, and potential adverse effects of treatment.

Fetal manifestations of maternal anti-Ro and La antibodies - more than complete heart block

Complete heart block (CHB) is a potentially fatal condition occurring in approximately 1:10000 fetuses. Whilst it is well recognised that maternal anti-Ro and La antibodies are associated with fetal CHB, there are multiple other manifestations of fetal exposure to these autoantibodies which are not widely appreciated and rarely diagnosed. The importance of identifying affected fetuses lies in the significantly increased risk of recurrence in future pregnancies, and the potential for treatments which may modify this risk. This paper presents several cases to highlight the varying fetal presentations of maternal anti-Ro and La antibodies.