What is your approach to screening for complete heart block in an asymptomatic pregnant patient with negative SSA and positive SSB antibodies?

There are case reports of congenital heart block (CHB) due to anti-RNP antibody in anti-SSA/SSB-negative pregnant women (Izmirly et al., PMID 28709760). However, it is so rare that too many fetal heart monitoring tests would need to be done to identify these rare events. The amount of time and money...