Predicting intrauterine infection risk in newborns based on morphometric parameters of placental terminal villi

Abstract

Aim. To evaluate the prognostic value of micromorphometry of placental terminal villi for early diagnosis of intrauterine infections in newborns.Materials and methods. A molecular genetic and micromorphometric study of 34 placentas obtained from women whose pregnancy ended in preterm labor at 30-36 weeks and 46 placentas of persons who gave birth to full-term babies was performed. In samples of placental tissue, the polymerase chain reaction was used to identify the genome of the following pathogens of intrauterine infections: Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma species (Ureaplasma urealyticum+Ureaplasma parvum), Chlamydia trachomatis, Streptococcus agalactiae, Streptococcus pyogenes, Staphylococcus aureus, Klebsiella pneumoniae, Haemophilus influenza, Listeria monocytogenes, Cytomegalovirus, Herpes simplex virus, Human herpes virus 4 type, Human herpes virus 6 type, Parvovirus B19. Morphometry was performed using an image analysis system on a Carl Zeiss microscope and Axio Imager software. An average number of capillaries in the terminal villi and the distance from the capillaries to the syncytiotrophoblast were calculated.Results. The genome of intrauterine infection pathogens was detected in 55.9% of placentas from preterm birth, including DNA of Ureaplasma species – 29.4%, Mycoplasma hominis – 23.5%, Mycoplasma genitalium – 5.9%, Streptococcus agalactiae – 11.7%, Cytomegalovirus – 5.9%, Human herpes virus 4 type – 14.8% as a part of mono- and co-infections. In full-term pregnancy, the infection of the placentas was found to be 3.4 times less – 16.3% (p<0.0002). In monoinfections, DNA of Ureaplasma species – 4.6%, Mycoplasma hominis – 6.9%, Streptococcus agalactiae – 2.3%, Human herpes virus 4 type – 2.3% were detected. An average number of capillaries (abs. value) in the terminal villi of infected placentas, both at full-term (5.35±1.07) and premature (3.97±0.19) pregnancies, proved to be significantly less than in uninfected placentas (5.74±0.05 and 4.63±0.28), respectively. An average distance from the capillaries (µm) of the terminal villi to the syncytiotrophoblast in infected placentas both at full-term (1.62±0.15) and premature pregnancies (2.20±0.2) proved to be significantly greater than in uninfected placentas (1.02±0.03 and 1.72±0.14, respectively).Conclusion. Comparison of the morphometric parameters of terminal villi in the examined placenta with an average rate of infected and uninfected placentas of full-term and premature pregnancies makes it possible to predict the risk of intrauterine infection in a newborn.