Choanal atresia - a recurrent feature of foetal carbimazole syndrome.

Keypoints • Choanal atresia is described as a feature of several congenital anomaly phenotypes. • Most cases of choanal atresia arises as an isolated clinical finding. • In utero exposure to carbimazole for maternal hyperthyroidism has been reported in five cases of choanal atresia. • We report another instance of this teratogenic cause of choanal atresia. • Maternal drug history is an important aspect of assessment in cases of choanal atresia.