Fig 1.
Representative villi from none, mild and marked TI categories.
A) A slide from a representative case at 23 weeks for which no TIs were identified. B) A slide from representative case at 38 weeks for which no TIs were identified. C) A slide from a representative case at 34 weeks that was in the ‘mild’ TI category. Four TIs were identified in this slide (indicated by rectangles) and an additional 3 TIs were identified in the second slide (not shown) from this case (average 3.5/slide = ‘mild’ category). The villi within the red rectangle are enlarged in panel E which demonstrates a single TI with central syncytiotrophoblast nuclei (arrow) surrounded by cytotrophoblasts (arrow heads). Intervillous space (I). D) A slide from a representative case at 24 weeks that was in the ‘marked’ TI category. Nine TIs were identified in this slide (indicated by rectangles) and an additional 10 TIs were identified in the second slide (not shown) from this case (average 9.5/slide = ‘marked’ category). The villi within the red rectangle are enlarged in panel F which demonstrates two TIs in one villus with central syncytiotrophoblast nuclei (arrows) surrounded by cytotrophoblasts (arrow heads). Intervillous space (I). Panels A-D are all at the same magnification, scale bar = 5 mm. Panels E and F are at the same magnification, scale bar = 50 μM.
Table 1.
Demographic and clinical characteristics.
Fig 2.
Odds ratios of having TIs in full versus preterm and stillbirth placentas.
Forest plot of adjusted odds ratios for identification of placental trophoblast inclusions across three birth outcomes.
Fig 3.
Earlier delivery as a function of TI frequency.
Whisker plot of the gestational age at delivery compared to trophoblast inclusion severity category. None (average of 0 TIs per slide), Mild (average of >0–5 TIs per slide), Marked (average of >5 TIs per slide).
Fig 4.
Association of TIs, birth outcomes, and placental pathologies.
Forest plot of unadjusted odds ratios for identification of placental trophoblast inclusions across pregnancy, birth, and placental pathology findings.