Histomorphometric parameters of normal full term placenta of Sudanese women

Abstract

The aim of the study was to provide values for morphometric parameters of histological components of normally delivered full term placentas of Sudanese women and compare them with reported parameters for other ethnic groups. A total of 200 histological sections, stained with hematoxylin and eosin and trichrome stains were used to give a final sample of 1000 fields saved as PowerPoint images for histomorphometry. A systematic random sampling procedure was adopted to ensure the optimum sample size that keeps the percentage error below 5% for the volume estimates. Standard stereological methods of point-counting and intersection-counting were applied to the microscopic fields to determine the volumes of placental components and surface area of fetal-maternal interface. The morphometric parameters showed no variations either between the placentas or between central and peripheral regions. The placental villi and the intervillus space occupied 65% and 35% of placental volume respectively with mean absolute values of 318 cm3 and 169 cm3. The mean absolute volume of the intervillus space was less than that of other ethnic groups by 8.67% but was significantly larger than that of the fetal capillaries which measured 41.2 cm3. The ratio of the absolute volume of the intervillus space to the volume of the fetal blood capillaries was 4:1 in both Sudanese and other ethnic groups. In the placental villi the fetal connective tissue together with the contained blood vessels larger than capillaries occupied 88% of the villus volume. The mean surface area of the fetal-maternal interface of the placental villi (syncytiotrophoblast) was 12.59 M2.

Systematic evaluation of velocity‐selective arterial spin labeling settings for placental perfusion measurement

“…The presence of fetal and maternal blood supply to the placenta adds to the complexity of interpreting the obtained perfusion images. Overall, we expect a larger contribution to the signal from maternal than fetal blood (at GA ~30 weeks relative volumes are roughly 70% vs 30% 38 ), assuming equivalent labeling efficiency on maternal and fetal sides.…”

Label-free detection of uptake, accumulation, and translocation of diesel exhaust particles in ex vivo perfused human placenta

“…Assuming that DEPs are round spheres with a mean diameter of 330 nm (according to the manufacturer’s Information, d(0.9), https://www-s.nist.gov/srmors/certificates/1650b.pdf ), a particle has a volume of 1.88 × 10 –20 m 3 and a mass of 3.38 × 10 –14 g with a density of 1.80 × 10 6 g/m 3 [ 31 ]. The average volume of a placenta is 500 cm 3 [ 32 ], leading to an estimated deposition of 353 μg of particles per placenta or 17.7 μg particles per cotyledon (20 cotyledons per placenta) during pregnancy. Taking into account the potential loss of particles to the perfusion system, some diffusion of the suspension into the surrounding tissues, and incomplete tissue uptake of the applied particles, a 3× safety margin was included in the calculation resulting in an applied concentration of 0.45 μg/mL (3 × 17.7 µg/120 mL PM) in the maternal circulation for the perfusion studies.…”

Comparison of Placental Parameters with Foetal growth in North Indian Population

“…There was not significant difference with in low birth placenta (159). Heidary 11 et al reported percentage volumes of the villi (66%) and inter villous space (34%) in cases of placenta previa of Iranian women whereas Abdalla 12 et al (2016) found out values for the normally implanted placenta in Sudanese women as 65%. Thus, it indicates that the site of implantation within the endometrium has no impact on the volume densities of the placental villi and the inter villous space.…”