Prevalence of placental bed spiral artery pathology in preeclampsia and fetal growth restriction: A prospective cohort study

Background: Preeclampsia and fetal growth restriction (PE/FGR) are pregnancy complications known to be associated with poor utero-placental function due to abnormal “physiological” remodeling of spiral arteries and unfavorable maternal cardiovascular health. However, the prevalence and degree of impaired spiral artery remodeling has not been clearly established. Method: Prospective, multi-center observational cohort study to assess the prevalence of lesions associated with abnormal development of spiral arteries in placental bed biopsies systematically obtained from 121 women undergoing Caesarian section for PE/FGR compared with a reference group of 149 healthy controls. Results: PE/FGR was associated with a high prevalence of impaired spiral artery remodeling compared with controls (63.6 vs 10.1 %, p < 0.001), and a higher prevalence of non-remodeled spiral arteries without the presence of intramural trophoblast (45.5 vs 6.7 %, p < 0.001), despite abundant interstitial trophoblast invasion in surrounding decidua and myometrium. Normal remodeling was associated with circumferential presence of intramural trophoblast and hardly any trophoblast in surrounding tissue. Acute atherosis (28.9 vs 3.4 %, p < 0.001) and thrombosis (16.5 vs 5.4 %, p = 0.003) lesions were significantly more prevalent in PE/FGR. Impaired remodeling, acute atherosis and thrombosis lesions were equally present in both decidual and myometrial segments of the spiral arteries in both groups. Impaired remodeling was most prominent in the groups with FGR (with or without PE) and thrombosis was most often seen in the group with PE and FGR. Conclusion: PE/FGR is associated with a high prevalence of impaired physiological remodeling and vascular lesions of the uterine spiral arteries in the placental bed.