Does 2D-Histologic identification of villous types of human placentas at birth enable sensitive and reliable interpretation of 3D structure?

INTRODUCTION: The villous tree of human placentas is a complex three-dimensional (3D) structure which enables fetomaternal exchange. Current concepts of microscopic analyses are based on the analysis of two-dimensional (2D) histologic sections. For this approach, the assessment of the stromal core of sectioned villi is of key importance. The classification of stromal properties of sectioned villi allows allocation of villous sections to villous types which are named by their expected position in villous trees (terminal, intermediate, and stem villi). METHOD: The present study takes these current concepts of placental histology as hypothesis and validates them against predetermined 3D positions of branches of villous trees. The 3D positions were determined prior to histologic sectioning using a recently introduced 3D-microscopic approach. Individual histologic sections of villi were classified by their stromal structures and inter rater variability of these histologic assessments were determined. RESULTS/DISSCUSSION: Inter rater variability was high and indicates substantial observer influence on the outcome of histologic assessments. Cross-match of villous types with the predetermined positions of villous branches of villous trees revealed substantial mismatch between the outcome of stromal classification and 3D-position of the sectioned villi in the placental villous trees.DFG, grant numbers INST 86/1495-1 FUGG, INST86/1452-1 LAGG.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.placenta.2015.10.00

Centrality of the Umbilical Cord Insertion in a Human Placenta Influences the Placental Efficiency☆

We assess the effect on placental efficiency of the non-centrality of the umbilical cord insertion and on chorionic vascular distribution to determine if cord centrality measurably affects placental function as reflected in birth weight

A SHAPE-CONTEXT MODEL FOR MATCHING PLACENTAL CHORIONIC SURFACE VASCULAR NETWORKS

Placental chorionic surface vascular networks (PCSVNs) are essential high-capacitance, low-resistance distribution and drainage networks, and are hence important to placental function and to fetal and newborn health. It was hypothesized that variations in the PCSVN structure may reflect both the overall effects of genetic and environmentally regulated variations in branching morphogenesis within the conceptus and the fetus’s vital organs. A critical step in PCSVN analysis is the extraction of blood vessel structure, which has only been done manually through a laborious process, making studies in large cohorts and applications in clinical settings nearly impossible. The large variation in the shape, color, and texture of the placenta presents significant challenges to both machine and human to accurately extract PCSVNs. To increase the visibility of the vessels, colored paint can be injected into the vascular networks of placentas, allowing PCSVNs to be manually traced with a high level of accuracy. This paper provides a proof-of-concept study to explain the geometric differences between manual tracings of paint-injected and un-manipulated PCSVNs under the framework of a shape-context model. Under this framework, paint-injected and un-manipulated tracings of PCSVNs can be matched with nearly 100% accuracy. The implication of our results is that the manual tracing protocol yields faithful PCSVN representations modulo a set of affine transformations, making manual tracing a reliable method for studying PCSVNs. Our work provides assurance to a new pre-processing approach for studying vascular networks by ways of dye-injection in medical imaging problems

Risk factors for uteroplacental vascular compromise and inflammation

To identify potentially modifiable risk factors of placental injury reflecting maternal uteroplacental vascular compromise (UPVC) and acute and chronic placental inflammation

Maternal risk factors for abnormal placental growth: The national collaborative perinatal project

<p>Abstract</p> <p>Background</p> <p>Previous studies of maternal risk factors for abnormal placental growth have focused on placental weight and placental ratio as measures of placental growth. We sought to identify maternal risk factors for placental weight and two neglected dimensions of placental growth: placental thickness and chorionic plate area.</p> <p>Methods</p> <p>We conducted an analysis of 24,135 mother-placenta pairs enrolled in the National Collaborative Perinatal Project, a prospective cohort study of pregnancy and child health. We defined growth restriction as < 10^thpercentile and hypertrophy as > 90^thpercentile for three placental growth dimensions: placental weight, placental thickness and chorionic plate area. We constructed parallel multinomial logistic regression analyses to identify (a) predictors of restricted growth (vs. normal) and (b) predictors of hypertrophic growth (vs. normal).</p> <p>Results</p> <p>Black race was associated with an increased likelihood of growth restriction for placental weight, thickness and chorionic plate area, but was associated with a reduced likelihood of hypertrophy for these three placental growth dimensions. We observed an increased likelihood of growth restriction for placental weight and chorionic plate area among mothers with hypertensive disease at 24 weeks or beyond. Anemia was associated with a reduced likelihood of growth restriction for placental weight and chorionic plate area. Pre-pregnancy BMI and pregnancy weight gain were associated with a reduced likelihood of growth restriction and an increased likelihood of hypertrophy for all three dimensions of placental growth.</p> <p>Conclusion</p> <p>Maternal risk factors are either associated with placental growth restriction or placental hypertrophy not both. Our findings suggest that the placenta may have compensatory responses to certain maternal risk factors suggesting different underlying biological mechanisms.</p

Acute Histologic Chorioamnionitis at Term: Nearly Always Noninfectious

Background: The link between histologic acute chorioamnionitis and infection is well established in preterm deliveries, but less well-studied in term pregnancies, where infection is much less common. Methodology/Principal Findings We conducted a secondary analysis among 195 low-risk women with term pregnancies enrolled in a randomized trial. Histologic and microbiologic evaluation of placentas included anaerobic and aerobic cultures (including mycoplasma/ureaplasma species) as well as PCR. Infection was defined as ≥1,000 cfu of a single known pathogen or a ≥2 log difference in counts for a known pathogen versus other organisms in a mixed culture. Placental membranes were scored and categorized as: no chorioamnionitis, Grade 1 (subchorionitis and patchy acute chorioamnionitis), or Grade 2 (severe, confluent chorioamnionitis). Grade 1 or grade 2 histologic chorioamnionitis was present in 34% of placentas (67/195), but infection was present in only 4% (8/195). Histologic chorioamnionitis was strongly associated with intrapartum fever >38°C [69% (25/36) fever, 26% (42/159) afebrile, P<.0001]. Fever occurred in 18% (n = 36) of women. Most febrile women [92% (33/36)] had received epidural for pain relief, though the association with fever was present with and without epidural. The association remained significant in a logistic regression controlling for potential confounders (OR = 5.8, 95% CI = 2.2,15.0). Histologic chorioamnionitis was also associated with elevated serum levels of interleukin-8 (median = 1.3 pg/mL no histologic chorioamnionitis, 1.5 pg/mL Grade 1, 2.1 pg/mL Grade 2, P = 0.05) and interleukin-6 (median levels = 2.2 pg/mL no chorioamnionitis, 5.3 pg/mL Grade 1, 24.5 pg/mL Grade 2, P = 0.02) at admission for delivery as well as higher admission WBC counts (mean = 12,000cells/mm$^3$ no chorioamnionitis, 13,400cells/mm$^3$ Grade 1, 15,700cells/mm$^3$ Grade 2, P = 0.0005). Conclusion/Significance: Our results suggest histologic chorioamnionitis at term most often results from a noninfectious inflammatory process. It was strongly associated with fever, most of which was related to epidural used for pain relief. A more ‘activated’ maternal immune system at admission was also associated with histologic chorioamnionitis