Abstract
Objective
A functional progesterone withdrawal has been thought to contribute to the pathophysiology
of spontaneous preterm birth (PTB). The density of the progesterone receptor (PR)
in gestational tissues could play a role in functional progesterone withdrawal. We
sought to understand the relationship between placental pathology and the density
of PR in the basal decidua in the setting of spontaneous preterm delivery.
Study Design
This is a secondary analysis of a retrospective cohort study of 40 patients with spontaneous
PTB < 37 weeks from a prior study at NorthShore University HealthSystem previously
described. Placental pathology was categorized according to the Amsterdam criteria
into acute inflammation (AI), chronic inflammation (CI), maternal vascular malperfusion
(MVM), and fetal vascular malperfusion (FVM). Slides containing basal decidua were
stained for PR. Ten distinct images were obtained from the basal plate of each placenta.
The positive cell detection program in QuPath image analysis software was used to
estimate the percentage of cells positive for PR (%PR + ). The mean %PR+ cells were
calculated from the ten representative images and were correlated with patterns of
placental injury using t-tests. Models were adjusted for gestational age at delivery.
Results
The median gestational age at delivery was 32.5 weeks (interquartile range: 30.5,
34.1). There was a lower density of %PR+ cells among those with AI (12.9%PR+ without
AI vs. 9.1%PR + with AI, p = 0.03). There were no differences in the percent of %PR+ cells based on CI, MVM,
or FVM. Models adjusted for gestational at delivery demonstrated persistent association
with PR density and AI and no difference in the other pathologies.
Conclusion
The presence of AI is associated with the lower density of PR expression in the basal
decidua by quantitative immunohistochemical analysis. Further research is needed to
investigate these findings in the context of spontaneous PTL and the prevention of
PTB.
Key Points
-
AI is associated with a lower density of PR expression.
-
PR is expressed in the basal decidua in the placenta.
-
Further research is needed to investigate findings in the context of PTB.
Keywords
placental pathology - preterm delivery - progesterone
