Pathological investigation of placentas in preeclampsia (the PEARL study)

ABSTRACT

INTRODUCTION: Preeclampsia (PE), but mainly preterm PE, is associated with deep placentation disorders. We aimed to compare placental pathologies in pregnancies affected by term and preterm PE compared to normal pregnancies.

METHODS: We performed a prospective case-cohort study. Low-risk nulliparous women were recruited in the first trimester and women who developed PE were recruited at diagnosis. Placental pathologies were reported according to the Amsterdam Placental Workshop Group Consensus Statement and were compared between cases and controls. PE cases stratified as term (≥37 weeks) and preterm PE (<37 weeks). Our primary outcome was maternal vascular malperfusion (MVM).

RESULTS: Twenty-four women who developed preterm PE were compared to 10 women who developed term PE and 41 women without PE. Preterm PE (92%) was associated with more MVM than term PE (10%, p < 0.01) and controls (4%, p < 0.01), but the rate of MVM was similar between term PE and controls (p = 0.56). Preterm PE was also associated with more placental infarcts (65% vs. 20% vs. 15%); advanced villous maturation (91% vs. 30% vs. 1%); and hypoplastic villous maturation (70% vs. 10% vs. 3%); and moderate to severe decidual vasculopathy (56% vs. 10% vs. 3%) than term PE and controls (all p < 0.05).

CONCLUSION: Most cases of preterm PE are associated with MVM, placental infarcts, advanced and/or hypoplastic villous maturation, and moderate to severe decidual vasculopathy, while it is infrequent in term PE and pregnancies without PE. Preterm and term preeclampsia have a different pathologic process that should be considered for their prevention and clinical management.

KEY WORDS:

• Preeclampsia
• maternal vascular malperfusion
• placental pathology

Disclosure of Interest

The authors have no financial or other conflict of interest to disclose.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was funded by the Jeanne-et-Jean-Louis-Levesque Perinatal Research Chair at Universite Laval. Alexandre Fillion holds master scholarships from the Canadian Institutes of Health Research (CIHR) and the Fonds de Recherche du Québec-Santé (FRQS). Emmanuel Bujoldholds a salary award from the FRQS. Paul Guerby holds a postdoctoral Award from the FRQS and INSERM (Institut National de la Santé et de la Recherche Médicale).