PREGNANCY AND AAD

Category A:  studies have failed to show risk to mother / fetus
Category B:  chance of fetal harm is remote, but a possibility
Category C:    risk cannot be ruled out
Category D and F:  Bad.  Bad, Bad, Bad.  

Here is a nice summary article from the ESC:  

https://www.escardio.org/Guidelines-&-Education/Journals-and-publications/ESC-
journals-family/E-journal-of-Cardiology-Practice/Volume-9/Tachyarrhythmias-and-
Pregnancy

To the best of my knowledge, there is no category A AAD.

The class B medications include some Beta-blockers - specifically Pindolol and
Acebutalol.  Atenolol is actually a category D (Yikes!!).  

The class C medications include metoprolol, diltiazem and verapamil, as well as
digoxin
                -Verapamil - although there have no reports of congenital
defects with it, it does crosses the placenta and affects the fetal CV system
                -Diltiazem:  felt to be "probably safe"
                -Digoxin also readily crosses the placent

As for class III AAD, sotalol has been categorized as a Category B.  

Of note, Pindolol (Category B) and Metoprolol (Category C) are safe with
lactation.  

In addition,  there is a nice article by the VA's own Dr. Joglar: 
http://www.ncbi.nlm.nih.gov/pubmed/9935279