Distinctive patterns of placental lesions in preeclampsia versus fetal growth restriction and their association with fetoplacental Doppler

Abstract

OBJECTIVES: The aim of this study was to describe placental histopathological findings in a large cohort of pregnancies complicated by preeclampsia and/or fetal growth restriction, and to investigate its association with fetoplacental Doppler. METHODS: This was a prospective observational study including pregnancies complicated by: 1) normotensive FGR defined as birthweight 95th centile for uterine and umbilical artery, or <5th centile for middle cerebral artery and CPR. Placental lesions were categorized to vascular (maternal/fetal side), inflammatory and other lesions according to the 2014 Amsterdam Placental Workshop Group Consensus Statement. Univariate and multiple regression analysis were performed for the comparison between the study groups. Logistic regression was used to determine abnormal Doppler association with placental lesions. RESULTS: Maternal side vascular lesions are significantly higher in PE compared to controls and normotensive FGR (PE&FGR: 73%, PE: 46%, FGR: 38% vs. controls: 31%; p=0.01) including 2 types of lesions: developmental (PE&FGR: 13%, PE: 5%, FGR: 3% vs. controls: 2%, p<0.001) and malperfusion (PE&FGR: 70%, PE: 39%, FGR: 32% vs. controls: 25%, p=0.001). In contrast, fetal side developmental lesions are significantly higher in normotensive FGR compared to controls and PE (PE&FGR: 0%, PE: 3%, FGR: 8% vs. controls 2%, p=0.001). All cases displayed lower prevalence of infectious lesions, with a high prevalence of immune lesions in PE&FGR (PE&FGR: 17.5%, PE: 7.8%, FGR: 9.8% vs. controls 9.4%, p=0.001). All fetoplacental Doppler parameters are associated with maternal side vascular lesions -mainly malperfusion- [uterine arteries mean PI (Odds ratio(OR)=2.45, 95% confidence interval (CI): 1.51 - 3.97), umbilical artery PI (OR=2.05, 95% CI: 1.02 - 4.47), middle cerebral artery PI (OR=2.75, 95% CI: 1.4 - 5.42), CPR (OR=1.75, 95% CI: 1.04 - 2.95)]. This association was evident mainly in the FGR groups -with and without PE-, being nonsignificant in controls or PE without FGR. No significant associations were observed between fetoplacental Doppler parameters and other placental lesions in any of the study groups. CONCLUSIONS: PE and FGR exhibit different patterns of placental histopathological lesions in accordance with the clinical manifestation of the placental disorder (maternal vs. fetal). Fetoplacental Doppler shows an association with placental malperfusion lesions in the maternal side, reinforcing its use as a surrogate of placental insufficiency.