Variation of Diffusion Distance from Foetal to Maternal Circulation at Different Gestational Periods

Abstract

Diffusion distance varies according to the gestational age of a mother. Moreover, this diffusion distance must be within a physiological range. Thus, the survivability of a growing foetus depends on this distance. For this study, 90 products of conception and placenta were collected and divided into three groups based on the trimester of pregnancy, and each group included 30 samples. Two tissue blocks were collected from each specimen after the sample was fixed with 10% formol saline for 48 hours. Afterwards, with further processing of the tissue, followed by H&E staining, the diffusion distance was measured among the three groups by using crossed sealed ocular micrometre under the light microscope. The ANOVA test was considered for further statistical analysis. In the first trimester, the placenta diffusion distance from foetal to maternal circulation ranged from 53.20 – 68.30 (μm), and the mean ± SD was 60.46 ± 3.58 (μm). In the second-trimester placenta, the diffusion distance of placenta from foetal to maternal ranged from 23.20 – 45.30 (μm), and the mean ± SD was 36.05 ± 6.01 (μm). In the third-trimester placenta, diffusion distance from foetal to maternal ranged from 1.80 – 2.90 (μm) and the mean ± SD was 2.52 ± 0.22 (μm). Diffusion distance significantly reduced with the ageing of the placenta (p < 0.00). With the help of this result, we can assume that the exchange of nutrients and gases proportionally increases with the advancement of pregnancy.