Choanal atresia associated with maternal hyperthyroidism treated with methimazole: a case-control study

Area of Science:

• Endocrinology
• Obstetrics
• Teratology

Background:

• Thyrotoxicosis affects 0.2% of pregnant women, with antithyroid drugs like methimazole (MMI) as standard treatment.
• Case reports suggest a link between prenatal MMI exposure and choanal atresia, but epidemiological studies show conflicting results.
• This study investigates the association between maternal hyperthyroidism treated with MMI and choanal atresia in offspring.

Purpose of the Study:

• To compare the frequency of maternal hyperthyroidism treated with MMI during pregnancy in children with choanal atresia versus controls.
• To identify potential causal factors for choanal atresia related to maternal hyperthyroidism and its treatment.

Main Methods:

• A multicenter case-control study involving 61 children with choanal atresia and 183 matched controls.
• Mothers were interviewed regarding medical history, pregnancy exposures, and specifically hyperthyroidism and MMI intake.
• Statistical analysis, including odds ratio (OR) calculation, was used to assess the association.

Main Results:

• Prenatal exposure to maternal hyperthyroidism treated with MMI was significantly higher in cases (16.4%) compared to controls (1.1%), with an OR of 17.75.
• No significant differences were found in socio-demographic factors, parental education, or other pregnancy exposures between cases and controls.
• Exposed cases exhibited some similar facial features.

Conclusions:

• Prenatal exposure to maternal hyperthyroidism treated with MMI is associated with choanal atresia.
• The findings suggest that maternal hyperthyroidism itself, rather than methimazole treatment, may be the primary causal factor for choanal atresia.
• Further research and literature review support the hypothesis that the maternal disease is the causal agent.