Carbimazole Embryopathy and Choanal Atresia

Congenital choanal atresia (CCA), especially the bilateral form, is a rare neonatal emergency. Its incidence is usually quoted as 1 in 5000 8000 live-births. [1] However, a recent epidemiological study involving more than 2.2 million deliveries suggests that CCA is extremely rare with a calculated incidence of 3 to 9 per 100,000 livebirths. [2] Athena is fascinated by CCA not only due to its rarity but also by the dramatic nature of symptoms. Refusal to suckle on ipsilateral breast of mother is pathognomonic of unilateral CCA while cyclical breathing (temporary relief of cyanosis by crying) is characteristic of bilateral disease. Occasionally, CCA may be a component of an established syndrome such as CHARGE association and Antley-Bixler syndrome. [1] Nevertheless, CCA is predominantly a sporadic malformation with no genetic predisposition. Etiology of the non-syndromic CCA has remained elusive until lately. Athena is intrigued by the recent revelation of a mysterious association between CCA and fetal thyroid function.