PLACENTAL VASCULAR-LESIONS AND LIKELIHOOD OF DIAGNOSIS OF PREECLAMPSIA

Objective: To test:he hypothesis that a range of severity of placental vascular lesions underlies preeclampsia and that the likelihood of it s clinical diagnosis increases with the extent and severity of uteropl acental vascular lesions. Methods: Four hundred sixty-five consecutive placentas of singleton, nonanomalous live-born infants born before 32 weeks' gestation were examined prospectively, and uteroplacental Vasc ular and related villous lesions were assigned a semiquantitative lesi on score based on severity and extent of lesions. The summed scores of individual lesions yielded a total uteroplacental vascular lesion sca re, ranging from 0 to 21, that was correlated with the odds of a clini cal diagnosis of preeclampsia, as well as with potential confounders, including maternal age, race, gestational age at delivery, and birth w eight centile. Statistical analysis was performed using contingency ta bles, one-way analysis of variance, multiple logistic regression, and receiver operating characteristic curve. P < .05 was considered signif icant. Results: A clinical diagnosis of preeclampsia was present in 78 of 465 (17%) cases. Logistic regression demonstrated that the total u teroplacental vascular lesion score related significantly to the diagn osis of preeclampsia (odds ratio 1.43, 95% confidence interval 1.31, 1 ,57) and this association was independent of gestational age at delive ry and birth weight centile. Preeclampsia was diagnosed in 12 of 284 ( 4%) cases with no or minimal histologic evidence of placental vascular injury (total score less than 4). Conversely, the diagnosis was not m ade in 4% of cases despite the presence of extensive placental vascula r injury (total score at least 14). Conclusion: The likelihood of clin ical diagnosis of preeclampsia before 32 weeks increases with progress ive impairment of the uteroplacental circulation. Histopathologic exam ination of the placenta can be used to confirm the diagnosis of preecl ampsia. (C) 1997 by The American College of Obstetricians and Gynecolo gists.