Endothelin and the Regulation of Uterine and Placental Perfusion in Hypoxia-Induced Fetal Growth Restriction

2004 ◽  
Vol 11 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Larry G. Thaete ◽  
Elizabeth R. Dewey ◽  
Mark G. Neerhof
2018 ◽  
Vol 79 (04) ◽  
pp. 396-401
Author(s):  
Hui Shi ◽  
Xianyue Quan ◽  
Wen Liang ◽  
Xinming Li ◽  
Bin Ai ◽  
...  

Abstract Objective The aim of this study was to investigate placental blood perfusion in middle and late pregnancy and explore its predictive value for fetal growth restriction (FGR). Methods All pregnant women included in the study were examined using placental intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI). Three IVIM parameters (D, f, D*) were obtained for each pregnant woman and analyzed using Image J software. Perfusion fraction f is a radiological marker of placental perfusion. The pulsatility index (PI) of the uterine artery is used to indirectly evaluate placental function. Results f-values were significantly lower in the late-onset FGR group compared to the normal late pregnancy group (19.07 vs. 27.78%). In addition, uterine artery PI values were markedly increased in the late-onset FGR group compared to the normal late pregnancy group (1.96 vs. 1.03), and neonatal weight was significantly lower in the late-onset FGR group (2.75 vs. 3.18 kg). There was a significant positive correlation between f-value, uterine artery PI and neonatal weight (r = 0.968, p < 0.01; r = 0.959, p < 0.01). There was a significant negative correlation between f-value and age of gestation (r = − 0.534, p < 0.01). Conclusion Perfusion fraction f was strongly correlated with uterine artery blood flow resistance as measured by color Doppler and had a certain predictive value for late-onset FGR.


2010 ◽  
Vol 298 (2) ◽  
pp. R312-R319 ◽  
Author(s):  
Tracy M. Tomlinson ◽  
Joel R. Garbow ◽  
Jeff R. Anderson ◽  
John A. Engelbach ◽  
D. Michael Nelson ◽  
...  

We assessed the use of magnetic resonance imaging (MRI) to define placental hypoxic injury associated with fetal growth restriction. On embryonic day 18.5 (E18.5) we utilized dynamic contrast-enhanced (DCE)-MRI on a 4.7-tesla small animal scanner to examine the uptake and distribution of gadolinium-based contrast agent. Quantitative DCE parameter analysis was performed for the placenta and fetal kidneys of three groups of pregnant C57BL/6 mice: 1) mice that were exposed to FiO2 = 12% between E15.5 and E18.5, 2) mice in normoxia with food restriction similar to the intake of hypoxic mice between E15.5 and E18.5, and 3) mice in normoxia that were fed ad libitum. After imaging, we assessed fetoplacental weight, placental histology, and gene expression. We found that dams exposed to hypoxia exhibited fetal growth restriction (weight reduction by 28% and 14%, respectively, P < 0.05) with an increased placental-to-fetal ratio. By using MRI-based assessment of placental contrast agent kinetics, referenced to maternal paraspinous muscle, we found decreased placental clearance of contrast media in hypoxic mice, compared with either control group (61%, P < 0.05). This was accompanied by diminished contrast accumulation in the hypoxic fetal kidneys (23%, P < 0.05), reflecting reduced transplacental gadolinium transport. These changes were associated with increased expression of placental Phlda2 and Gcm1 transcripts. Exposure to hypoxia near the end of mouse pregnancy reduces placental perfusion and clearance of contrast. MRI-based DCE imaging provides a novel tool for dynamic, in vivo assessment of placental function.


2019 ◽  
Vol 62 (2) ◽  
pp. R155-R165 ◽  
Author(s):  
Bethany Hart ◽  
Elizabeth Morgan ◽  
Emilyn U Alejandro

Fetal growth restriction is one of the most common obstetrical complications resulting in significant perinatal morbidity and mortality. The most frequent etiology of human singleton fetal growth restriction is placental insufficiency, which occurs secondary to reduced utero-placental perfusion, abnormal placentation, impaired trophoblast invasion and spiral artery remodeling, resulting in altered nutrient and oxygen transport. Two nutrient-sensing proteins involved in placental development and glucose and amino acid transport are mechanistic target of rapamycin (mTOR) and O-linked N-acetylglucosamine transferase (OGT), which are both regulated by availability of oxygen. Impairment in either of these pathways is associated with fetal growth restriction and accompanied by cellular stress in the forms of hypoxia, oxidative and endoplasmic reticulum (ER) stress, metabolic dysfunction and nutrient starvation in the placenta. Recent evidence has emerged regarding the potential impact of nutrient sensors on fetal stress response, which occurs in a sexual dysmorphic manner, indicating a potential element of genetic gender susceptibility to fetal growth restriction. In this mini review, we focus on the known role of mTOR and OGT in placental development, nutrient regulation and response to cellular stress in human fetal growth restriction with supporting evidence from rodent models.


Author(s):  
Priya Singh ◽  
Hena Saiyda

Background: Severe early-onset fetal growth restriction can lead to a range of adverse outcomes including fetal or neonatal death, neurodisability, and lifelong risks to the health of the affected child. Sildenafil, a phosphodiesterase type 5 inhibitor, potentiates the actions of nitric oxide, which leads to vasodilatation of the uterine vessels and might improve fetal growth in utero. The objective is to evaluate effectiveness and safety of Sildenafil citrate for treatment of Doppler velocimetry of uterine, umbilical artery for systolic/diastolic ratio (S/D ratio) at first visit, after 2 hours and then after 12 weeks of treatment.Methods: A case control study was carried out in 96 antenatal women with fetal growth restriction over a period of twelve months. A written informed consent was obtained. Out of 96, 12 were lost to follow up. Of remaining 84 women, 42 were included in the study group and 42 in the control group. First group (case) received Sildenafil citrate 50 mg stat followed by colour Doppler after 2 hours and then 25 mg three times a day for 12 weeks. The second group (control) received placebo in for 12 weeks.Results: Sildenafil treatment was associated with a significant increase in length of pregnancy (P> 0.05) overall mean S/D ratio pre-sildenafil was 5.34±0.93 which reduced to 5.18 ± 0.95 after 2 hours of sildenafil administration and this significant was highly significant (p<0.0001).and also the mean S/D ratio pre-treatment was 6.72±0.38 which decreased to 3.52±0.47 after 12 weeks of sildenafil administration. The difference between them was found to be extremely significant (p<0.0001).Conclusions: Sildenafil citrate can improve utero-placental perfusion and length of pregnancy in pregnancies complicated by IUGR. It appears to have a significantly positive effect on fetal weight. Sildenafil treatment may offer a new opportunity to improve perinatal outcomes, for pregnancies complicated by IUGR. However, these observations require further studies on wide scale.


Author(s):  
Yakubova D.I.

Objective of the study: Comprehensive assessment of risk factors, the implementation of which leads to FGR with early and late manifestation. To evaluate the results of the first prenatal screening: PAPP-A, B-hCG, made at 11-13 weeks. Materials and Methods: A retrospective study included 110 pregnant women. There were 48 pregnant women with early manifestation of fetal growth restriction, 62 pregnant women with late manifestation among them. Results of the study: The risk factors for the formation of the FGR are established. Statistically significant differences in the indicators between groups were not established in the analyses of structures of extragenital pathology. According to I prenatal screening, there were no statistical differences in levels (PAPP-A, b-hCG) in the early and late form of FGR.


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