P23.02: The fetal larynx and pharynx–anatomy and development

heat, until the last third of pregnancy). The ultrasound examinations were performed by two veterinarians using a SonoAce 8000 live (Medison, Seoul, Korea) with multifrequency convex volumetric transducer (2–5 MHz). The right and left kidney were evaluated in three periods (days 0, days 1–20 and days 21–40) by three techniques (ellipsoid, VOCAL 12◦ and VOCAL 30◦) by two observers (block acquiring and ultrasound volumetric analysis, being ‘‘blind’’ with each other). We calculated mean, median, standard deviation, maximum and minimum values and the scatter plot of these 18 variables. Results: We collected 150 blocks for each observer. The result of inferential block ANOVA revealed the interaction effect between side and time (P = 0.009). The three ultrasound techniques presented an average of the same renal volume (P = 0.137), regardless the side and time. At day 0 (P = 0.001) and 21st up to 40th days (0.023), the right side presented greater renal volume when compared with the left side. Renal volume increased within the progression of the pregnancy, taking in consideration the right side, the kidney volume at day 0 was lower than the 21st up to 40th day (P = 0.029), taking in consideration the left side, the renal volume in day 0 was statistically lower than day 1 up to 20st day (P = 0.020) and 21st up to 40th day (P = 0.007). There wasn’t correlation of these data with maternal age, number of pregnancies or number of fetuses. Good intraobserver reproducibility was found and none of the three techniques presented a good interobserver reproducibility. Conclusions: The data showed that both of the volumetric methods of 3DUS VOCAL correlated well with the volume obtained by 2DUS, besides showing higher quality pictures and many render modes.