Changes of laryngeal parameters during intrauterine life

OBJECTIVE: Increased care of fetal and neonatal airways has led to advances in neonatal medicine. The early diagnosis and treatment of respiratory diseases require a detailed knowledge of fetal airway anatomy and development. The aim of this study was to determine the anatomical development of the thyroid and cricoid cartilages and their structural variability during fetal life. MATERIALS AND METHODS: The study was performed on the thyroid and cricoid cartilages of 55 human fetal larynges of both sexes, between the ages of 13 and 27 weeks of intrauterine life. Numerous measurements of the thyroid and cricoid cartilages were performed. RESULTS: Correlations between the obtained results were calculated in relation to the crown-rump (C-R) length of human fetuses and to sex. The structural variability of the thyroid and cricoid cartilages of human male and female fetuses in subsequent weeks of intrauterine life was observed. In both genders a correlation between laryngeal size and fetal crown-rump length, regardless of sex, was found. The thyroid cartilage presents a sexual dimorphism. CONCLUSIONS: The results of this study can be useful in the analysis of prenatal examinations, and in planning the treatment of airway emergencies.