MORPHOMETRIC PARAMETERS OF MATURITY OF PLACENTAL CHORINAL VILLI IN PREMATURE LABOR
Authors: Tokar P.Yu. 
Published: April 2024

Aim – to establish some morphometric parameters of placental villi in premature birth in comparison with physiological pregnancy.Material and methods. The material (30 placentas in premature births and 30 placentas in physiological pregnancies) was fixed for 22-24 hours in a neutral buffered 10% formalin solution. Next, the material was dehydrated in an ascending battery of alcohols and embedded into paraffin at 580С. Serial histological sections 5 μm thick were made on a sled microtome. After deparaffinization, serial histological sections were stained with hematoxylin and eosin, and with a chromotrope - water blue according to N.Z.Slinchenko. In addition to the descriptive method of histopathological examination, computer morphometry was performed on previously obtained digital copies of optical microscopic images of the tissue (Delta Optical Evolution 100 microscope {planachromatic lenses according to the required optical magnification} and Olympus SP550UZ digital camera). Digital copies of the image were analyzed using a freeware copy of the ImageJ v1.52 computer program specialized for digital histometric studies. In particular, the percentage of different types of chorionic villi was calculated on digital copies of optical images using the unrepeatable score test method. The obtained digital data were processed statistically. In particular, with the help of a copy of the free (freeware) computer program for statistical calculations PAST v 4.14, a preliminary test for the normality of the distribution was applied according to the Wilkie-Hahn-Shapiro test. For all studied statistical samples, according to this criterion, the hypothesis about the normality of the distribution was not rejected (at p=0.05), therefore, parametric methods of statistical analysis were used: calculation of the arithmetic mean and its error, the odd two-sided Student's test. Along with the Student's test, the non-parametric Mann-Whitney U test was also used. Results. It was considered most important to start assessing the state of the placenta according to the percentage ratios between different types of villous formations. In particular, according to modern ideas about different types of chorionic villi in the II and III trimesters of pregnancy, the following types of villous formations of the placenta were distinguished: stem villi ("early" and late"), intermediate villi (immature and mature), terminal villi, terminal "specialized" villi, mesenchymal villi, embryonic villi, trophoblastic and villous processes. The total amount of the specified villi should be equal to 100%. The division of villi into primary, secondary, and tertiary villi is relevant only for the 1st trimester of pregnancy, therefore, it is not suitable for studying the morphological features of premature birth.Conclusions. According to the obtained morphometric data, the immaturity of the chorionic tree is noted in premature birth compared to physiological pregnancy. This can be seen from a noticeable increase in the percentage of stem "early" villi, intermediate immature and mature villi, mesenchymal and embryonic villi, trophoblastic and villous processes, but with a significant decrease in the percentage of terminal villi.