No abstract

Failure to transform uteroplacental spiral arteries is thought to underpin disorders of pregnancy, including preeclampsia and fetal growth restriction (FGR). In this study, spiral artery remodeling and extravillous-cytotrophoblast were examined in placental bed biopsies from normal pregnancy (n=25), preeclampsia (n=22), and severe FGR (n=10) and then compared with clinical parameters. Biopsies were immunostained to determine vessel wall integrity, extravillous-cytotrophoblast location/density, periarterial fibrinoid, and endothelium. Muscle disruption was reduced in myometrial spiral arteries in preeclampsia ( P =0.0001) and FGR ( P =0.0001) compared with controls. Myometrial vessels from cases with birth weight <5th percentile ( P <0.001), abnormal uterine Doppler ( P <0.01), abnormal umbilical artery Doppler ( P <0.001), and preterm delivery ( P <0.001) had less muscle destruction compared with >5th percentile. Fewer extravillous-cytotrophoblast surrounded both decidual and myometrial vessels in the normal group and preeclampsia group compared with the FGR group ( P =0.001). For myometrial vessels, the normal group contained more intramural extravillous-cytotrophoblast than in preeclampsia ( P =0.015). Decidual vessels in the FGR group had less fibrinoid deposition compared with controls ( P =0.013). For myometrial vessels, less fibrinoid was deposited in both the preeclampsia group ( P =0.0001) and the FGR group ( P =0.01) when compared with controls, and less fibrinoid was deposited in the preeclampsia group when compared with FGR group ( P <0.001). Myometrial vessels obtained from birth weights <5th percentile had less periarterial fibrinoid than those with >5th percentile ( P <0.02). A major defect in myometrial spiral artery remodeling occurs in preeclampsia and FGR that is linked to clinical parameters. Interstitial extravillous-cytotrophoblast is not reduced in preeclampsia but is increased in FGR.

No abstract

Higher early pregnancy levels of sFlt-1 and PlGF were associated with a decreased risk of adverse perinatal outcome.

The purpose of this study was to examine the expression of hemeoxygenases HO-1 and HO-2, which are responsible for the production of carbon monoxide (CO), in the human placenta and placental bed and to determine the role of inhibitors of HO on placental perfusion pressure. We hypothesized that HO is expressed within the placenta and that invading cytotrophoblast cells (CTB) express HO isoforms. The expression of HO-1 and HO-2 was studied on placenta and placental bed biopsies, obtained using a transcervical sampling technique, from normal human pregnancies between 8 and 19 wk gestation and at term. In the placenta, HO-2 immunostaining was prominent in syncytiotrophoblast in the first trimester and reduced toward term (P<0.0005). HO-2 endothelial immunostaining was weak in the first trimester, but increased by term (P<0.0005). Within the placental bed, HO-2 was expressed by CTB in cell columns, the cytotrophoblast shell, and cell islands. Both intravascular CTB and interstitial CTB expressed HO-2. HO-1 immunostaining was low in the placenta but intense on the CTB within the placental bed. A striking feature was the absence of HO-1 from the proximal layers of cell columns, with strong expression on the more distal CTB layers of the cell columns. In placental perfusion studies, a significant dose-dependent increase in perfusion pressure was observed in the presence of zinc protoporphyrin, an inhibitor of HO. These results suggest a role for CO in placental function, trophoblast invasion, and spiral artery transformation. Hemeoxygenase expression in human placenta and placental bed implies a role in regulation of trophoblast invasion and placental function.