Measurements of foetal growth via transabdominal ultrasonography during first half of pregnancy at ewes from synthetic population Bulgarian milk

I. Ralchev, N. Metodiev, E. Raicheva, D. Dimov

Abstract: The aim of present work was to determine values of some measurements of foetal growth via transabdominal ultrasonography during first half of pregnancy at ewes from Synthetic Population Bulgarian Milk. Two parallel experiments were carried out with ewes, which were in different gestational phases. The first experiment was carried out with 19 ewes, conceived in three consecutive days. Three consecutive ultrasound observations in 10 days intervals were done, on days 40-42, 51-53 и 61- 63 after conceiving. The following measurements were taken: head diameters: biparieatal (BPD) and occipito-nasal (ONL), Placentome size: width and length. The second experiment was carried out with 17 ewes, conceived in the same day. The examination days were 25, 36 and 46 after artificial insemination. It was measured: Day 25: diameter of embryonic vesicle; length of embryo Day 36: crown-rump length; Day 46: crown-rump length; head diameters: biparieatal (BPD) and occipito-nasal (ONL); placentome size: width and length. All measurements were in millimeters (mm). The effect of gestational phase on foetal growth is analysed by one way ANOVA. The coefficients of correlation (r) and determination (R²) between gestational phase and embryofetal measurements were established by standard regression. The gestational phase influence significantly ((P<0.001) all taken measurements. The mean values for BPD were11.16 mm on 40-42 gestational days and reached 21,08 mm on 61-63 days, and for ONL -15.17 mm on 40-42 days and reached 32.94 mm on 61-63 days. The size of palcentomes varied in wide range for all taken measurements. On days 40-42 the mean values were: length- 13.67 mm and width – 10.06 mm, and reached on 61-63 days mean length – 33.02 mm and mean width – 21.33 mm. It was established high, positive and significant correlation between head diameters and gestational age (r=0.93*** и r=0.93***). It was obtained moderate values of the coefficient of determination for the size of placentomes and gestational age (R²= R²= 0.46 и R²= 0.47). The embroyfetal length was 11.08 mm on day 25, 26.03 mm on day 36 and 51.79 mm on day 46. It was established high, positive and significant correlation between CRL and gestational age (r= 0.84***).

Keywords: ewe; foetal measurements; gestational age; ultrasound

Date published: 2019-07-23