Utility of cardiac monitoring in fetuses at risk for congenital heart block: The PR interval and dexamethasone evaluation (PRIDE) prospective study

Deborah M. Friedman, Mimi Y. Kim, Joshua A. Copel, Claudine Davis, Colin K.L. Phoon, Julie S. Glickstein, Jill P. Buyon

Research output: Contribution to journalArticlepeer-review

264 Scopus citations


Background-Anti-SSA/Ro-associated third-degree congenital heart block is irreversible, prompting a search for early markers and effective therapy. Methods and Results-One hundred twenty-seven pregnant women with anti-SSA/Ro antibodies were enrolled; 95 completed an evaluable course in 98 pregnancies. The protocol included fetal echocardiograms performed weekly from 16 to 26 weeks' gestation and biweekly from 26 to 34 weeks. PR intervals >150 ms were considered prolonged, consistent with first-degree block. Ninety-two fetuses had normal PR intervals. Neonatal lupus developed in 10 cases; 4 were neonatal lupus rash only. Three fetuses had third-degree block; none had a preceding abnormal PR interval, although in 2 fetuses >1 week elapsed between echocardiographic evaluations. Tricuspid regurgitation preceded third-degree block in 1 fetus, and an atrial echodensity preceded block in a second. Two fetuses had PR intervals >150 ms. Both were detected at or before 22 weeks, and each reversed within 1 week with 4 mg dexamethasone. The ECG of 1 additional newborn revealed a prolonged PR interval persistent at 3 years despite normal intervals throughout gestation. No first-degree block developed after a normal ECG at birth. Heart block occurred in 3 of 16 pregnancies (19%) in mothers with a previous child with congenital heart block and in 3 of 74 pregnancies (4%) in mothers without a previous child with congenital heart block or rash (P=0.067). Conclusions-Prolongation of the PR interval was uncommon and did not precede more advanced block. There was a trend toward more congenital heart block in fetuses of women with previously affected offspring than those without previously affected offspring. Advanced block and cardiomyopathy can occur within 1 week of a normal echocardiogram without initial first-degree block. Echodensities and moderate/severe tricuspid regurgitation merit attention as early signs of injury. (Circulation. 2008;117:485-493.).

Original languageEnglish (US)
Pages (from-to)485-493
Number of pages9
Issue number4
StatePublished - Jan 29 2008
Externally publishedYes


  • Antibodies
  • Atrioventricular node
  • Echocardiography
  • Heart block
  • Immunology
  • Pregnancy

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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