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Purpose: The placenta is a vital organ for the exchange of oxygen, nutrients, and waste products between fetus and mother. The placenta may suffer from several pathologies, which affect this fetal-maternal exchange, thus the flow properties of the placenta are of interest in determining the course of pregnancy. In this work, we propose a new multiparametric model for placental tissue signal in MRI., Methods: We describe a method that separates fetal and maternal flow characteristics of the placenta using a 3-compartment model comprising fast and slowly circulating fluid pools, and a tissue pool is fitted to overlapping multiecho T2 relaxometry and diffusion MRI with low b-values. We implemented the combined model and acquisition on a standard 1.5 Tesla clinical system with acquisition taking less than 20 minutes., Results: We apply this combined acquisition in 6 control singleton placentas. Mean myometrial T2 relaxation time was 123.63 (±6.71) ms. Mean T2 relaxation time of maternal blood was 202.17 (±92.98) ms. In the placenta, mean T2 relaxation time of the fetal blood component was 144.89 (±54.42) ms. Mean ratio of maternal to fetal blood volume was 1.16 (±0.6), and mean fetal blood saturation was 72.93 (±20.11)% across all 6 cases., Conclusion: The novel acquisition in this work allows the measurement of histologically relevant physical parameters, such as the relative proportions of vascular spaces. In the placenta, this may help us to better understand the physiological properties of the tissue in disease., (© 2018 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.)

Introduction: Our objective was to elucidate the overall diagnostic accuracy of ultrasound in detecting the severity of abnormally invasive placentation (AIP)., Material and Methods: Medline, Embase, CINAHL and The Cochrane databases were searched. The ultrasound signs explored were: loss of hypoechoic (clear) zone in the placental-uterine interface, placental lacunae, bladder wall interruption, myometrial thinning, focal exophitic mass, placental lacunar flow, subplacental vascularity, and uterovesical hypervascularity., Results: Twenty studies (3209 pregnancies) were included. Ultrasound had an overall good diagnostic accuracy in identifying the depth of placental invasion with sensitivities of 90.6%, 93.0%, 89.5%, and 81.2% for placenta accreta, increta, accreta/increta, and percreta, respectively; the corresponding specificities were 97.1%, 98.4%, 94.7%, and 98.9%. Placental lacunae had sensitivities of 74.8%, 88.6%, and 76.3% for the detection of placenta accreta, increta, and percreta, respectively. Sensitivity and specificity of loss of the clear zone in identifying placenta accreta were 74.9% and 92.0%, whereas the corresponding figures for placenta increta and percreta were 91.6% and 76.9%, and 88.1% and 71.1%. Lacunar flow had sensitivities of 81.2%, 84.3%, and 45.2% for the detection of placenta accreta, increta, and percreta respectively; the corresponding figures for specificity were 84.0%, 79.7%, and 75.3%. Sensitivity of uterovesical hypervascularity was low for the detection of placenta accreta (12.3%) but high for placenta increta (94.4%) and percreta (86.2%); the corresponding figures for specificity were 90.8%, 88.0% and 88.2%, respectively., Conclusions: Ultrasound has an overall good diagnostic accuracy in recognizing the depth and the topography of placental invasion., (© 2017 Nordic Federation of Societies of Obstetrics and Gynecology.)

Objective: To evaluate the usefulness of three-dimensional ultrasound (3D US), magnetic resonance imaging (MRI) and three-dimensional power Doppler angiography (3D-PDA) in the preoperative assessment of myometrial invasion in endometrial carcinoma., Design: A prospective observational study., Setting: University hospital., Population: Twenty consecutive patients diagnosed with endometrial carcinoma., Methods: Preoperative 3 T MRI and 3D US examinations were performed, and the depth of myometrial invasion was assessed. The vascularity indices, vascularization index, flow index and vascularization flow index, were calculated by 3D-PDA., Main Outcome Measures: The results were compared with the final histopathology report after a surgical staging., Results: In detecting deep myometrial invasion, the sensitivity of 3D US, MRI and their combination was 50, 91.7 and 100%, respectively. The specificity was 87.5, 50 and 50%, respectively. There were no significant differences in the 3D-PDA vascularity indices between the two groups., Conclusions: MRI appears to be more sensitive than 3D US in detecting deep invasion, while 3D US has a better specificity., (© 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.)

Background: The purpose of this study is to determine whether there is any difference for vascular endothelial growth factor expression in placentae and myometrial resistance arteries from control and pre-eclamptic patients to clarify the source of the increased total vascular endothelial growth factor in pre-eclampsia., Methods: With placentae tissue samples and small pieces of myometrium from the controls (n=10) and pre-eclampsia patients (n=7), vascular endothelial growth factor immunohistochemistry and mRNA in situ hybridization were performed. We also measured the serum vascular endothelial growth factor levels by competitive enzyme immunoassay at the same time., Results: Vascular endothelial growth factor was identified primarily in syncytiotrophoblast in placental tissue, and it was also identified in smooth muscle cells in the myometrium and perivascular smooth muscle in myometrial resistance arteries. However, there were no differences in vascular endothelial growth factor expression between the groups in the presence of elevated serum levels of total vascular endothelial growth factor in pre-eclamptic patients (median 18.2 ng/ml versus 4.9 ng/ml)., Conclusion: This study suggests that the placenta and perivascular smooth muscle are not the origin of the increased total vascular endothelial growth factor in pre-eclampsia. To clearly understand the role of vascular endothelial growth factor in pre-eclampsia, further studies are required to determine the sites of increased vascular endothelial growth factor synthesis.

1. Pre-eclampsia is a serious pregnancy disorder associated with widespread activation of the maternal vascular endothelium. Recent evidence implicates a role for oxidative stress in the aetiology of this condition. 2. Reactive oxygen species, particularly superoxide anions, invokes endothelial cell activation through many pathways. Oxidant-induced cell injury triggers the activation of nuclear enzyme poly(ADP-ribose) polymerase (PARP) leading to endothelial dysfunction in various pathophysiological conditions (reperfusion, shock, diabetes). 3. We have studied whether the loss of endothelial function in pre-eclampsia is dependent on PARP activity. Endothelium-dependent responses of myometrial arteries were tested following exposure to either plasma from women with pre-eclampsia or normal pregnant women in the presence and absence of a novel potent inhibitor of PARP, PJ34. Additional effects of plasma and PJ34 inhibition were identified in microvascular endothelial cell cultures. 4. In myometrial arteries, PARP inhibition blocked the attenuation of endothelium-dependent responses following exposure to plasma from women with pre-eclampsia. In endothelial cell cultures, plasma from pre-eclamptics induced measurable oxidative stress and a concomitant increase in PARP activity and reduction in cellular ATP. Again, these biochemical changes were reversed by PJ34. 5. These results suggest that PARP activity plays a pathogenic role in the development of endothelial dysfunction in pre-eclampsia and promotes PARP inhibition as a potential therapy in this condition.

Background: The process of physiological conversion of spiral arteries is dependent on the invasion of the interstitium and spiral arteries of the uterine wall by invasive extravillous trophoblast thereby creating a high flow-low resistance vessel. Quantitative data on restriction of trophoblast invasion and failure of spiral artery transformation are limited in preeclampsia., Aim: This study morphometrically analyzes interstitial trophoblast cells and trophoblast cells embedded in the wall of the converted spiral arteries within the decidua and myometrium of normotensive and preeclamptic Black African pregnant women., Methods: Placental bed biopsies were obtained from 25 normotensive pregnant women and 30 pregnant women complicated with hypertensive disorders. Biopsies were processed and immunostained for trophoblast cell identification, using anti-MNF 116 antibody. Image analysis of the trophoblast population within the decidua, myometrium and the spiral arteries was performed in the normotensive and in the severe proteinuric hypertensive groups., Results: The mean field area percentage of trophoblast cells observed in the decidua of the normotensive women was 22.79 +/- 2.1% in comparison to 18.14 +/- 1.53% in the severe hypertensive group (p < 0.01). In the myometrium, the mean field area percentage of interstitial trophoblast cells (both mononuclear and multinuclear) was 10.04 +/- 2.1% of the field area of the normotensive group compared to 2.81 +/- 0.67% in the severe hypertensive group (p < 0.001). The mean field area percentage occupied by trophoblast cells in myometrial spiral arteries was 10.15% in the normotensive group compared to none in the severe hypertensive group. The latter group displayed medial disorganization, hyperplasia and endothelial vacuolation., Conclusion: This study demonstrates restricted invasion of the trophoblastic cells in preeclampsia. This inadequate invasion may influence vascular remodeling required for delivering adequate volumes of maternal blood to the placenta.

Endothelium-dependent responses were assessed in myometrial small arteries isolated from pregnant women, using pressure myography. Responses to bradykinin were unaffected by the combined presence of the nitric oxide synthase (NOS) inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 100 micro M) and the cyclo-oxygenase inhibitor, indomethacin (10 micro M). The additional presence of clotrimazole (50 micro M) attenuated, but did not abolish, vasodilator responses to bradykinin. Raising extracellular [K(+)] (by between 1 and 15 mM) did not evoke a vasodilator response, nor did the cannabinoids, anandamide and methanandamide. Responses to bradykinin were attenuated in the presence of the gap junction inhibitors 18-alpha-glycyrrhetinic acid (18-alpha GA, 100 micro M), carbenoxolone (100 micro M) and palmitoleic acid (50 micro M). SR141716A, the CB(1) receptor antagonist attenuated responses to bradykinin, but only at high concentrations (10 micro M). These results suggest that gap junctional communication is involved in the nitric oxide (NO)- and prostanoid-independent vasodilator responses to bradykinin in myometrial small arteries in normal pregnancy.

Background: To study placental bed biopsy changes in placenta previa and normally implanted placenta., Subject and Method: Fifty placental bed biopsies from 50 patients with placenta previa and 50 placental bed biopsies from normally implanted placenta were taken at cesarean section. Placental bed biopsy was stained with hematoxyline and eosin for histological examination. Both the groups were compared for trophoblastic invasion and vascular changes of placental bed spiral arteries. Statistical analysis was done by Chi-square test., Results: Placenta bed biopsy was representative in 42/50 (84%) biopsy samples of the study group (placenta previa) and 35/50 (70%) of the control group (normally located placenta). Trophoblastic giant cell migration into decidua was present in 100% of representative samples of both the groups while migration into myometrium was seen in 66.67% and 51.14% of samples of study and control group. Average number of trophoblastic giant cells per sample was significantly higher in placenta previa (decidua 41.3%, myometrium 52%) than the control group (decidua 17.4%; myometrium 14.5%). Trophoblastic giant cell infiltration into myometrial spiral arterioles was higher in placenta previa (81.83 cells per vessel). Percentage of myometrial spiral arterioles showing physiological changes was significantly higher in the study group (50.39%) compared to the control group (21.14%). Incidence of inflammatory cell infiltration was higher in the study group (42.86%). Hemorrhage into decidua and myometrium were seen in biopsy samples of the placenta previa., Conclusion: Placenta previa is associated with significantly higher trophoblastic giant cell infiltration and physiological changes of the myometrial spiral arterioles.

Objectives: The effects of cromakalim and pinacidil on the contractile activity of the isolated human myometrium and intramyometrial arteries were studied., Material and Method: Myometrial strips and pieces of uterine arteries were obtained from women undergoing hysterectomy. Contractions were recorded under isometric conditions., Results: Both compounds (10(-9) M-5 x 10(-6) M) inhibited the spontaneous activity of the myometrium and vasopressin induced contractions of myometrium and intramyometrial arteries. There was no statistically significant difference in the responses of both tissues to cromakalim or pinacidil. Both compounds reduced responses of myometrium and intramyometrial arteries to low concentration of K+ (< 40 mM) but did not decrease contractions induced by 40 mM and 80 mM., Conclusion: The combined effect on the uterus and intrauterine vasculature would suggest a potential in the use of cromakalim or pinacidil for the treatment of dysmenorrhea.

Objective: To compare the effect of endothelin on isolated resistance arteries from different vascular beds in normal and preeclamptic women before and after pretreatment with the ETA receptor antagonist BQ-123., Materials and Methods: Resistance arteries from myometrial and omental biopsies obtained at cesarean section of normal pregnant and preeclamptic women were dissected and mounted in organ baths for recording of isometric tension. The contractile response to endothelin-1 in presence and absence of BQ-123 was recorded., Results: Endothelin-1 induced similar concentration-dependent contractions in all arteries investigated. In women with preeclampsia the contractile response induced by endothelin-1 was significantly higher in omental as compared to myometrial vessels. Pretreatment with BQ-123 significantly shifted the concentration-response curve to the right but only reduced the maximum contractile response in omental vessels., Conclusion: Endothelin-1 is a potent constrictor of resistance arteries from different vascular beds in normal pregnancy and preeclampsia. The contractile effect is at least in part mediated by ETA receptors, since it was significantly reduced after pretreatment with BQ-123. In preeclamptic but not in normal pregnant women the response to endothelin-1 was reduced in myometrial as compared to omental arteries, possibly secondary to receptor down regulation.

This study was performed to evaluate the in vitro effects of a new polypeptide, endothelin-1 (ET-1) on small intramyometrial vessels in comparison with the action of noradrenalin (NA). In connection with cesarean section, myometrial biopsies were obtained and small arteries (100-500 microns in diameter) were excised. Cylindrical segments of these vessels were used for registration of contractile activity after administration of ET-1 and NA. ET produced vasoconstriction and was approximately three times as powerful and 70-fold as potent as NA. It is suggested that ET may be involved in the regulation of human utero-placental blood flow.

Cases of endometrial carcinoma (104) from the Cancer Registry of Miyagi Prefecture, Japan, during the period from 1966--1977 have been reviewed histologically. The most impressive differences between tumors in this low-risk population and those reported in American women are higher frequencies of the mixed adenosquamous histology, myometrial vascular invasion, and lymphoid infiltration within and around the tumors in the Japanese cases. The possible significance of these observations, both clinical and epidemiologic, is discussed in detail.

Intervillous blood flow was measured by a new intravenous 133Xe method before and during induction of general anesthesia for cesarean section in 10 healthy mothers. The flow values showed a highly significant decrease (p less than 0.001) (35 per cent on an average) at the time of anesthesia compared with the control values. The impairment was observed in all the cases. The role of the maternal changes in hemodynamic parameters and acid-base balance as a background of this decrease is discussed.

Decidual and intramyometrial spiral arteries from 18 insulin-dependent diabetic and 18 non-diabetic women were compared histologically. All women were normotensive and none had signs of pre-eclampsia. None of the infants in either group had intra-uterine growth retardation. Metabolic control in the diabetic women was assessed by pregnancy glucose level from the last trimester of pregnancy and by C-peptide in amniotic fluid and cord blood as a measure of the fetal beta-cell function. The intramyometrial and decidual parts of the spiral artery were normal in the non-diabetic group. None of the diabetic patients showed pathological changes in the intramyometrial part of the spiral artery. Two of the 18 diabetic patients had pathological changes (intramural fibrosis) in the decidual portion of the spiral artery. These two women had signs of diabetic angiopathy (White's class D and F) and in one of them, the background diabetic retinopathy progressed markedly during pregnancy. The pregnancy glucose level was above normal (greater than 6.2 mM/l) in 3 of 18 diabetics. The C-peptide values in amniotic fluid and cord blood were above normal in 11 of 17 and in 5 of 17, respectively. Both patients with spiral artery lesions had pregnancy glucose levels in the upper range, 5.86 and 5.98 mM/l, respectively and the highest value of C-peptide in the amniotic fluid and cord blood, suggesting exaggerated fetal beta-cell function.

The pelvic congestion syndrome is an ill-defined entity and despite clinical signs and symptoms diagnosis is almost always presumptive. We studied the clearance of 133Xenon injected into the cervical myometrium, the aim being to evaluate the usefulness of the method as a diagnostic tool in this condition. At the interoperative controls signs of pelvic congestion were present in 40 patients and absent in 36. The mean cervico-myometrial blood flow was 14.28 +/- 6.46 ml/100 g/min in the first group and 25.13 +/- 7.07 ml/100 g/min in the second (p less than 0.01). We obtained false negative responses in 6 cases, false positive ones in 2 and doubtful ones in 16 cases.

Regional blood flow in the myometrium and myomata has been measured during laparotomy in 11 patients using locally injected 133Xenon. Blood flow was calculated from the wash-out curves using both initial slope technique and compartment analysis. Assuming equal partition coefficients in myometrium and myomata the following values in ml-min-1-100 g-1 are seen: initial slope technique-myometrium 15.6 +/- 2.29, myomata 5.1 +/- 0.95, compartment analysis-myometrium 20.01 +/- 3.21, myomata 5.5 +/- 1.16. The blood flow was always lower in myomata than in myometrium of the same uterus. The main reason for the reduction of blood flow per unit weight of uterus in patients with myomata previously reported thus seems to be low blood flow in the myomata. A slight reduction of blood flow in the surrounding myometrium, however, also seems probable.