Evidence that fetal death is associated with placental aging.

BACKGROUND: The risk of unexplained fetal death or stillbirth increases late in pregnancy, suggesting that placental aging is an etiological factor. Aging is associated with oxidative damage to DNA, RNA, and lipids. We hypothesized that placentas at >41 completed weeks of gestation (late-term) would show changes consistent with aging that would also be present in placentas associated with stillbirths. OBJECTIVE: We sought to determine whether placentas from late-term pregnancies and unexplained stillbirth show oxidative damage and other biochemical signs of aging. We also aimed to develop an in vitro term placental explant culture model to test the aging pathways. STUDY DESIGN: We collected placentas from women at 37-39 weeks' gestation (early-term and term), late-term, and with unexplained stillbirth. We used immunohistochemistry to compare the 3 groups for: DNA/RNA oxidation (8-hydroxy-deoxyguanosine), lysosomal distribution (lysosome-associated membrane protein 2), lipid oxidation (4-hydroxynonenal), and autophagosome size (microtubule-associated proteins 1A/1B light chain 3B, LC3B). The expression of aldehyde oxidase 1 was measured by real-time polymerase chain reaction. Using a placental explant culture model, we tested the hypothesis that aldehyde oxidase 1 mediates oxidative damage to lipids in the placenta. RESULTS: Placentas from late-term pregnancies show increased aldehyde oxidase 1 expression, oxidation of DNA/RNA and lipid, perinuclear location of lysosomes, and larger autophagosomes compared to placentas from women delivered at 37-39 weeks. Stillbirth-associated placentas showed similar changes in oxidation of DNA/RNA and lipid, lysosomal location, and autophagosome size to placentas from late-term. Placental explants from term deliveries cultured in serum-free medium also showed evidence of oxidation of lipid, perinuclear lysosomes, and larger autophagosomes, changes that were blocked by the G-protein-coupled estrogen receptor 1 agonist G1, while the oxidation of lipid was blocked by the aldehyde oxidase 1 inhibitor raloxifene. CONCLUSION: Our data are consistent with a role for aldehyde oxidase 1 and G-protein-coupled estrogen receptor 1 in mediating aging of the placenta that may contribute to stillbirth. The placenta is a tractable model of aging in human tissue.

TNF-R1 as a first trimester marker for prediction of pre-eclampsia.

OBJECTIVE: To examine whether the maternal serum concentration of the soluble receptor-1 of tumor necrosis factor-α (TNF-R1) at 11-13 + 6 weeks of gestation is a predictor of development of pre-eclampsia (PE). METHODS: This is a nested case-control study in which the concentration of TNF-R1 at 11 + 0 to 13 + 6 weeks was measured in 426 pregnant women in the first trimester. TNF-R1 values were expressed as multiples of the median (MoM) adjusted for maternal factors. The distributions of log TNF-R1 MoM in the control group and hypertensive disorders (early-PE [ePE], late-PE [lPE] and gestational hypertension [GH]) groups were compared. Logistic regression analysis was used to determine whether maternal factors, TNF-R1 or their combination make a significant contribution to the prediction of PE. Screening performance was determined by analysis of receiver-operating characteristics curves. RESULTS: Median concentration of TNF-R1 (ng/ml) was higher in ePE (2.62 ± 0.67), lPE (2.12 ± 0.56) and GH (2.19 ± 0.45) compared to controls (2.04 ± 0.42), p = 0.001. Logistic regression analysis demonstrated that the addition of TNFR-1 to maternal factors did not make a significant contribution to the prediction of PE. CONCLUSIONS: The maternal serum TNF-R1 concentration at 11-13 + 6 weeks of gestation was increased in pregnancies which developed hypertensive disorders, however, the addition of TNFR-1 did not improve the detection rate of these conditions compared with maternal factors alone.