Table 3.
Frequency of acute inflammatory placental lesions of normal singleton pregnant women at term.
| Histologic Lesionsa | % (n/N) |
|---|---|
| Acute inflammatory lesions | 42.3% (400/946) |
| A. Maternal inflammatory response | 36.2% (342/946) |
| Stage 1: early acute subchorionitis or chorionitis | 23.3% (220/946) |
| Grade 1 | 23.3% (220/946) |
| Grade 2 | 0% (0/946) |
| Stage 2: acute chorioamnionitis | 12.2% (115/946) |
| Grade 1 | 12.2% (115/946) |
| Grade 2 | 0% (0/946) |
| Stage 3: necrotizing chorioamnionitis | 0.7% (7/946) |
| Grade 1 | 0.6% (6/946) |
| Grade 2 | 0.1% (1/946) |
| B. Fetal inflammatory response | 23.3% (220/946) |
| Stage 1: chorionic vasculitis or umbilical phlebitis | 18.7% (177/946) |
| Grade 1 | 18.6% (176/946) |
| Grade 2 | 0.1% (1/946) |
| Stage 2: umbilical arteritis | 4.4% (42/946) |
| Grade 1 | 4.4% (42/946) |
| Grade 2 | 0% (0/946) |
| Stage 3: necrotizing funisitis | 0.1% (1/946) |
| Grade 1 | 0.1% (1/946) |
| Grade 2 | 0% (0/946) |
a
Placentas may have more than one type of acute placental inflammatory lesions.