A morphometric study of prenatal development of the human larynx.

INTRODUCTION Precise knowledge of the anatomy and development of the airways in the fetus is needed for advances in neonatal medicine. The aim of this study was to assess the morphometry of the larynx during fetal development. MATERIAL AND METHODS The study was performed on 47 human fetal larynges (27 male and 20 female) collected between the age of 13-27 weeks of intrauterine life according to Pineau and preserved in 10% buffered formalin. Five measurements of each larynx were performed: total height of the larynx, height of the anterior wall, height of the posterior wall of the larynx, sagittal diameter of the aperture of the larynx, and external sagittal diameter of the cricoid cartilage. Correlations between the results and crown-rump (C-R) length of human fetuses in relation to gender were analyzed. The percentage ratio of laryngeal length to C-R length in subsequent weeks of the fetal period and in relation to gender was determined. RESULTS Dimensions of the larynx were found to correlate with crown-rump length. Mean lengths of the larynx were greater in male than in female fetuses at some stages of development. CONCLUSION Ultrasound dimensions of the larynx are greater than dimensions found during postmortem examinations.