Abstract
Objective Fetal tachyarrhythmias complicate 0.5% of pregnancies, with high morbidity and mortality.
We hypothesized that maternal factors may predispose to fetal supraventricular tachycardia
(SVT).
Study Design We reviewed medical records of all 124 mothers who presented to the Vanderbilt Fetal
Cardiology Clinic from 2004 to 2010 for fetal arrhythmias, excluding heart block.
Maternal factors were compared between 28 fetuses with SVT and a control group of
112 fetuses screened for noncardiac conditions. The proportions were analyzed using
chi-square or Fisher exact test for categorical variables and Wilcoxon rank sum test
for continuous variables.
Results Of maternal factors, thyroid disease was statistically significant compared with
controls. Among mothers whose fetuses had SVT, 21% had thyroid disease (83% hypothyroidism)
compared with 3% of controls (p < 0.001).
Conclusion In this cohort, the maternal thyroid disease was more common in fetuses with SVT
compared with controls (odds ratio = 9.8, 95% confidence interval 2.3–42.3), suggesting
closer screening for fetal arrhythmias and SVT in mothers with thyroid disease. Also,
routine screening of thyroid functions and thyroid autoantibodies may be warranted
in mothers of fetuses with SVT.
Keywords
fetal arrhythmias - supraventricular tachycardia - thyroid disease - autoimmune disease
