Antithyroid drugs and congenital heart defects: ventricular septal defect is part of the methimazole/carbimazole embryopathy

Birth defects after use of antithyroid drugs in early pregnancy: a Swedish nationwide study

“…MMI exposure was associated with a higher incidence of heart septal defects in both studies. The Danish study showed a dominant feature of VSD (18). ASD was the predominant subtype in this study, but VSD was observed among children exposed to both MMI and PTU.…”

“…ASD was the predominant subtype in this study, but VSD was observed among children exposed to both MMI and PTU. Previous reports have indicated that heart septal defect may be part of the MMI embryopathy (18). The clinical impact of such defect after ATD exposure needs to be addressed in further studies with longer followup; however, we noticed that the majority of children identified with heart septal defects after ATD exposure in the present study had registrations of multiple malformations.…”

Antithyroid Drug Use in Pregnancy and Birth Defects: Why Some Studies Find Clear Associations, and Some Studies Report None

“…and eye, urinary, respiratory, and cardiovascular defects. The latter were mainly ventricular septal defects (14). The most common PTU-associated defect consisted of a pre-auricular sinus or cyst with fistula, a birth defect that is considered minor and is often not registered.…”

Follow-up and evaluation of the pregnancy outcome in women of reproductive age with Graves’ disease after 131Iodine treatment

“…131 I therapy has become an increasingly popular treatment for patients of hyperthyroidism because of the adverse effects, such as liver injury and embryopathy, associated with the ATD drugs PTU [15, 16], MMI and carbimazole (CM) [17, 18]. 131 I therapy has many advantages over other types of treatments, such as simple application, definitive curative effect, low recurrence rate, and low cost.…”