Can placental histology reveal preexisting hypertension in patients who develop preeclampsia?

Hypertension can be both a cause and a consequence of preeclampsia, complicating diagnosis and postpartum management. Placental histopathology has been proposed as a tool to distinguish preeclampsia superimposed on chronic hypertension from de-novo disease, yet specific and reliable markers remain poorly defined.

To evaluate the association between placental histological features and preexisting hypertension in a cohort of patients who developed preeclampsia.

We conducted a retrospective analysis of 321 preeclamptic pregnancies at a tertiary center between January 1, 2020, and October 31, 2023. Preexisting hypertension was defined as the use of antihypertensive medication at the beginning of pregnancy. Placental histopathological evaluation was available for 223 patients. Histological lesions were classified according to established guidelines, with a focus on maternal vascular malperfusion features. Associations between placental lesions and preexisting hypertension were assessed using univariate and multivariate analyses.

The absence of placental infarction (47.4 vs. 61.1%, P  = 0.02) and the presence of decidual arteriopathy (31.6 vs. 16.8%, P  = 0.03) were significantly associated with preexisting hypertension. The combination of these two features was independently associated with preexisting hypertension (odds ratio = 5.90; 95% confidence interval 1.88-18.60; P  < 0.01). This pattern demonstrated high specificity (96.2%) but low sensitivity (18.4%) for identifying preexisting hypertension.

The presence of decidual arteriopathy in the absence of placental infarction is strongly associated with preexisting hypertension in preeclamptic patients. Although its low sensitivity limits its use as a screening tool, its high specificity suggests that it may serve as a useful indicator of underlying chronic hypertension when present. These findings support the potential role of placental histopathology as an adjunct to clinical evaluation in the postpartum assessment of hypertensive disorders.