A management strategy for fetal immune-mediated atrioventricular block

Abstract

Introduction. The purpose of this study is to describe an in utero management strategy for fetuses with immune-mediated 2° or 3° atrioventricular (AV) block.

Methods and results. The management strategy as applied to 29 fetuses consisted of three parts. First, using fetal echocardiography and obstetrical ultrasound, we assessed fetal heart rate (FHR), heart failure, growth and a modified biophysical profile score (BPS) assessing fetal movement, breathing and tone. Second, we treated all fetuses with transplacental dexamethasone, adding terbutaline if the FHR was <56 bpm. Digoxin and/or intravenous immune globulin (IVIG) was added for progressive fetal heart failure. Third, we delivered fetuses by cesarean section for specific indications that included abnormal BPS, maternal/fetal conditions, progression of heart failure, or term pregnancy. We assessed perinatal survival, predictors of delivery and maternal/fetal complications in 29 fetuses with 3° (n = 23) or 2° (n = 6) AV block. There were no fetal deaths. In utero therapy included dexamethasone (n = 29), terbutaline (n = 13), digoxin (n = 3) and/or IVIG (n = 1). Delivery indications included term gestation (66%), fetal/maternal condition (14%), low BPS (10%) and progression of fetal heart failure (10%). An abnormal BPS correlated with urgent delivery.

Conclusion. These results suggest that applying this specific management strategy that begins in utero can improve perinatal outcome of immune-mediated AV block.

Keywords:

• Atrioventricular block
• fetus
• SSA/SSB antibodies
• dexamethasone
• terbutaline

Acknowledgements

The authors thank James Huhta MD, Ms. Jenny Leshko R.N. and Ms. Pam Humiston for data collection from the Congenital Heart Institute of Florida; Ms. Nancy Davis and Vivian Cui M.D. for statistical consultation, and Ms. Rita Allen for manuscript preparation. They acknowledge the invaluable contributions to the clinical care of the subjects in this report by the many obstetricians and maternal fetal medicine in the greater Chicago and Tampa Bay areas, as well as our colleagues in pediatric cardiology, electrophysiology and cardiothoracic surgery at the Heart Institute for Children, Chicago, IL and the Congenital Heart Institute of Florida, St. Petersburg, FL. Dr. Benson is supported by Grant HL69712 from the National Institute of Health.