Comparison of uteroplacental blood flow in normal and in intrauterine growth-retarded pregnancy. Measurements with Indium-113m and a computer-linked gammacamera

Uteroplacental blood flow was studied with a noninvasive method using indium-113m and a computer-linked gammacamera. The blood flow was determined from the ratio of the maximum and the rise time of the isotope accumulation curve of the placenta. Eight pregnancies with intrauterine growth retardation (IUGR) were compared with 11 normal pregnancies. In the IUGR group the mean placental blood flow was only 1/4 of corresponding mean values of the normal group. The difference was highly significant (p less than 0.01).     

Hypertension Induced by Episodic Reductions in Uteroplacental Blood Flow in Gravid Rat

Background. The etiology of preeclampsia remains unclear. Animal modeling of preeclampsia has been useful; however, no model to date represents episodic changes in uteroplacental blood flow that may occur in preeclampsia. Objective. To develop a gravid rat model characterized by episodic reductions in uteroplacental blood flow. Method. Pregnant Sprague Dawley rats were used and subjected to SHAM, reduced uterine perfusion pressure (RUPP), or aortic occlusion on gestational Day 14. Aortic occlusion surgery consisted of implantation of a silastic vascular occluder around the abdominal aorta and silver clips around the uterine–ovarian arteries. Aortic occlusion animals were subjected to five consecutive days of occlusion (40% reduction) each session lasting 1 h. On Day 21, maternal mean arterial pressure (MAP) and fetal morphology were assessed. For isolated blood vessels, resistance-sized mesenteric arteries were harvested and mounted on a pressure arteriograph. Result. Occluder animals experienced a 10 mmHg rise in MAP as compared to SHAM (p < 0.05), and RUPP MAP was significantly increased as compared to control subjects (p < 0.05). Pups from Occluder animals exhibited a decrease in fetal weight as compared to SHAM (p < 0.05), but an increase in fetal weight as compared to RUPP (p < 0.05). Myogenic reactivity of second-order mesenteric arteries increased in Occluder animals as compared to SHAM (p < 0.05), but were similar to that of RUPP. Conclusion. Episodic reductions in uteroplacental blood flow play a crucial role in the altered vascular reactivity seen in Occluder animals and may represent a new model to investigate the mechanisms associated with episodic reductions in uteroplacental blood flow in pathological pregnancies.     

Whole Blood Platelet Aggregation in Normal Pregnancy and Pre-Eclampsia

Platelet aggregation in whole blood in response to ADP, plasma beta-thromboglobulin (beta-TG) and thromboxane B₂ (TXB₂) levels, were evaluated in third-trimester patients with pre-eclanipsia (PE) (n=15) and in healthy third-trimester pregnant controls (n=43). 1 min after blood collection there was no difference in platelet response to ADP between PE and controls. Storage of blood unmasked hypoaggregability of platelets in PE implicating contribution of labile pro-aggregatory substance to ADP-induced aggregation tested at I min. Plasma TXB₂ in 10 controls (39.4 ± 8.7 pg/ml) was lower (p<0.05) than in 4 PE subjects (212.8 ± 130.0 pg/ml). Thus, seemingly normal aggregation of platelets to ADP in PE at I min after blood collection may be attributed to increased plasma level of TXA₂. Increased plasma level of beta-TG in PE (49.2 ± 7.0 ng/ml vs 27.3 ± 3.0 ng/ml; p<0.01) appears to be secondary to platelet consumption in which circulating TXA₂ may play a role.     

Rheological and Physiological Consequences of Conversion of the Maternal Spiral Arteries for Uteroplacental Blood Flow during Human Pregnancy

Physiological conversion of the maternal spiral arteries is key to a successful human pregnancy. It involves loss of smooth muscle and the elastic lamina from the vessel wall as far as the inner third of the myometrium, and is associated with a 5–10-fold dilation at the vessel mouth. Failure of conversion accompanies common complications of pregnancy, such as early-onset preeclampsia and fetal growth restriction. Here, we model the effects of terminal dilation on inflow of blood into the placental intervillous space at term, using dimensions in the literature derived from three-dimensional reconstructions. We observe that dilation slows the rate of flow from 2 to 3 m/s in the non-dilated part of an artery of 0.4–0.5 mm diameter to approximately 10 cm/s at the 2.5 mm diameter mouth, depending on the exact radius and viscosity. This rate predicts a transit time through the intervillous space of approximately 25 s, which matches observed times closely. The model shows that in the absence of conversion blood will enter the intervillous space as a turbulent jet at rates of 1–2 m/s. We speculate that the high momentum will damage villous architecture, rupturing anchoring villi and creating echogenic cystic lesions as evidenced by ultrasound. The retention of smooth muscle will also increase the risk of spontaneous vasoconstriction and ischaemia–reperfusion injury, generating oxidative stress. Dilation has a surprisingly modest impact on total blood flow, and so we suggest the placental pathology associated with deficient conversion is dominated by rheological consequences rather than chronic hypoxia.     

卵巢浆液性肿瘤组织微血管密度和血管阻力及分级的特点

目的:探讨具有相似形态特征不同病理性质的卵巢浆液性肿瘤的血管阻力指数(RI)和血管分级的特点,以及两者与微血管密度(MVD)的相关性及临床参考价值。方法:回顾性分析2012年10月—2014年7月天津市人民医院和天津市中心妇产科医院收治的76例卵巢浆液性肿瘤患者,依据术后病理结果分为3组:良性组30例,病理结果为良性浆液性囊腺瘤,囊内可见分隔或乳头样实性组织,不包括单纯性浆液性囊腺瘤;交界性组24例,病理结果为交界性浆液性囊腺瘤;Ⅰ期癌组22例,病理结果为浆液性囊腺癌,国际妇产科联盟(FIGO)卵巢癌分期为Ⅰ期癌。观察经阴道彩色多普勒(TVCDU)检测RI和三维能量多普勒(3D-CPA)血管分级,评价卵巢浆液性肿瘤的血流特点,并与MVD进行相关性研究。结果:不同病理性质的卵巢浆液性肿瘤的MVD比较差异有统计学意义(F=69.08,P0.001),其中Ⅰ期癌组高于良性组和交界性组(P0.001);3组RI比较差异有统计学意义(F=17.36,P0.001),其中良性组高于交界性组和Ⅰ期癌组(P0.001),交界性组与Ⅰ期癌组比较差异无统计学意义(P0.05);3组3D-CPA血管分级比较差异有统计学意义(χ~2=27.263,P0.001),其中良性组以Ⅰ级血流为主(63.3%),交界性组和Ⅰ期癌组以Ⅱ、Ⅲ级血流为主(分别为70.8%、100%),良性组与交界性组和Ⅰ期癌组比较差异有统计学意义(P0.017),交界性组与Ⅰ期癌组间差异无统计学意义(P=0.0340.017)。3D-CPA血管分级与MVD呈正相关(rs=0.794,P0.01),RI与MVD呈负相关(r=-0.786,P0.01)。结论:RI和3D-CPA可用于术前评估肿瘤血管血流特点,辅助用于具有相似形态特征的卵巢浆液性肿瘤的病理分型。     

Measurements of Blood Pressure, Oedema and Proteinuria in a Pregnant Population of New Zealand

Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects.     

Measuring Venous Capacitance and Blood Flow in Pregnancy

Summary: Forearm or calf venous plethysmography has been used in pregnant women to examine the effects of pregnancy on the vascular system and more recently to measure blood flow changes in response to intra-arterial infusion of vasoactive substances. To examine the assumption that venous capacitance and blood flow measurements are the same in the forearm and calf, venous plethysmography was conducted simultaneously on the forearm and calf in normal (NP) and hypertensive pregnant women (HTP) in their third trimester and in normal nonpregnant women (N). Ail studies were made on the right forearm and calf with subjects in the left lateral recumbent position. There was no significant difference between venous capacitance in the forearm (median: 124 times 10³rruV100mIVmrnHg for both NP and HTP) and leg (134 [NP] and 106 [HTP] x lO'mL/lOOmlVmmHg) for both pregnant groups but venous capacitance in the nonpregnant group was greater in the leg than arm (174 versus 112 x lO'mUlOOmL/mmHg, p <0.001). Blood flow was similar in the leg and forearm (median: 4.9 versus 3.9mL/100mL/min respectively) in nonpregnant women. Forearm blood flow was also similar to calf flow in NP women (6.2 versus 4.3mL/100mL/min respectively) but greater man calf blood flow in HTP (9.7 versus 5.3ml7100mL/min, p <0.01). Using left lateral recumbency, forearm and calf vein capacitances are similar in pregnant women, in contrast to nonpregnant women. Blood flow is higher in the forearm than the calf only in hypertensive pregnant women. These observations should be borne in mind when interpreting studies of regional blood flow in pregnancy.     

Uteroplacental blood flow in pregnant women with hypertension and recurrent spontaneous abortion.

Uterine velocimetry was performed in 13 pregnant women with pregnancy induced hypertension (PIH) and in 15 pregnant women with recurrent spontaneous abortion syndrome (RSA-S). Measurement were performed on both uterine arteries and averaged. 75% of PIH group had RI 95th percentile from the first measurement (20 weeks gestation). In the RSA-S group, RI was between 75th and 95th percentile, suggesting an almost pathological vascularization.     

Hemodynamic Changes with Paradoxical Blood Flow in Expectant Management of Abruptio Placentae

Background: Because the early diagnosis of abruption often is missed or misinterpreted, emergency situations frequently do not permit adequate management.Case: A woman of 26-weeks’ gestation was transferred with symptoms and laboratory findings typical for abruption. Ultrasound, including Doppler, revealed a subchorionic hematoma, pathologic blood flow in the uterine arteries, low pulsatility index values in the fetal cerebral and umbilical arteries (paradoxical blood flow), and high maximal velocities in the fetal aorta. Repeated Doppler and laboratory examinations revealed a gradual restoration to normal of the arterial uterine blood flow pattern, of paradoxical blood flow, aortic maximal velocities, and laboratory values.Conclusion: Serial Doppler measurements considering the paradoxical pattern illustrate pathophysiologic mechanisms of abruption that may assist in deciding whether to deliver immediately or to continue intense surveillance.     

子痫前期高危孕妇阿司匹林抵抗与基因多态性相关性

子痫前期是妊娠期特有的高血压疾病,近年尤其是早发型子痫前期,是孕产妇和新生儿发病和死亡的重要原因。低剂量的阿司匹林在国外已明确用于子痫前期的预防,可以减少子痫前期的发展,并降低早产和胎儿生长受限的发生率。但部分患者不能达到预期效果,存在阿司匹林抵抗。在阿司匹林预防血栓相关研究中同样存在阿司匹林抵抗现象。目前基因多态性与阿司匹林抵抗的相关性已成为研究热点。研究较多的有ABC转运蛋白家族基因、环氧合酶(COX)基因(COX-1和COX-2)、TXA2R基因、ADP受体基因、GP受体等基因多态性及其相互作用。由于其在孕妇中鲜有研究而在心脑血管疾病中研究较多,现重点从基因多态性角度阐述在心脑血管疾病中阿司匹林抵抗的可能机制,以指导阿司匹林在孕妇这类特殊人群的用药,改善妊娠结局。     

妊娠期肝内胆汁淤积症患者脐血流检测与围产儿预后

目的 :探讨妊娠期肝内胆汁淤积症 (ICP)患者胎儿脐动脉血流阻抗特点及围产儿结局的影响。方法 :用胎儿脐血流检测仪检测 4 3例 ICP患者和 5 8例正常孕妇胎儿脐动脉血流阻力指标。结果 :ICP患者胎儿脐动脉血流阻力指标及围产儿结局不良的发生率均明显升高。结论 :ICP患者应常规进行胎儿脐动脉血流阻力检测 ,以便及时处理以改善ICP患者围产儿预后     

Uteroplacental circulation and functional status of the fetoplacental unit in risk pregnancies with special reference to late gestosis

Trial to define position and variability of radioisotope functional diagnostics of placental perfusion in comparison with urinary estrogen excretion by serial examinations. - In case of placental insufficiency estrogen values are significantly reduced starting from the 32nd to 35th gestational week as compared with normal values. In general, placenta perfusion shows delayed half-life periods of the increase in activity in all risk pregnancies beginning from the 28th week of pregnancy. A direct correlation between estrogen values and placenta perfusion can only be detected in cases of chronic placental insufficiency with intrauterine growth retardation. A prolonged perfusion time reveals a fetal hypotrophy in 53% of the cases. Late gestosis takes the first place about all risk pregnancies, connected with placental insufficiency in 30% of the cases. The tendency towards a development of placental insufficiency can be early detected by determination of placental perfusion time.     

妊娠滋养细胞肿瘤子宫病灶彩色多普勒血流显像动态观察

目的探讨化疗前后妊娠滋养细胞肿瘤(GTT)血流动力学变化.方法利用彩色多普勒血流显像图(CDBFI)动态检测18例GTT患者化疗前及每疗程化疗后子宫动脉,病灶内血流指数,并选取同期20例非孕正常妇女子宫动脉阻力指数作为对照.结果GTT患者化疗前子宫动脉及病灶内血流呈现低阻状态;化疗后随hCG的下降,CDBFI示整个血流逐渐减少,病灶内血流丰富区范围缩小,子宫动脉及病灶内血流参数逐渐恢复正常.化疗前和1～3疗程化疗后子宫动脉处RI明显低于正常非孕妇女(P＜0.01),4疗程化疗后子宫动脉RI与正常非孕妇女相近.结论彩色多普勒血流显像图检查对妊娠滋养叶肿瘤的诊断有帮助,通过动态观察可间接估价患者对化疗的敏感性.     

Cerebral Blood Flow and Metabolism in Ovine Fetuses During Asphyxia Resulting in Seizures

Severe fetal asphyxia can cause neurologic damage, but little is known about cerebral oxidative metabolism under these conditions. This study was designed to measure cerebral blood flow and oxygen consumption during severe global asphyxia in fetal sheep, asphyxiated to the point at which seizure activity subsequently occurred. Six sheep were chronically instrumented with fetal electrodes, fetal and maternal vascular catheters, and an adjustable occluder on the maternal common hypogastric artery. Measurements were made of fetal arterial blood gases, blood pressure, heart rate electrocorticogram (ECoG), nuchal muscle electromyogram (EMG), and regional blood flow (radioactive microspheres) during control, and at 30 and 60 min after complete occlusion of the maternal hypogastric artery. The ECoG became isoelectric, and the fetuses developed a marked respiratory and metabolic acidosis, the pH falling to 6.99 ± 0.03, the pCO₂ rising to 73 ± 11 mm Hg, and base excess falling to ?16 ± 1 mEq/L at 60 min of occlusion. Control fetal arterial blood pressure was 52 ± 9 mm Hg and did not change significantly with asphyxia at 60 min. Cerebral cortical blood flow was 127 ± 54 ml/100 g/min at control, and 204 ± 130 ml/100 g/min at 60 min of asphyxia. Cerebral oxygen consumption was 201 ± 50 μM/100 g/min at control, and 76 ± 57 μM/100 g/min at 60 min of asphyxia (P < 0.05), i.e., 45% of control. All 6 fetuses had episodic seizure activity based on ECoG and nuchal EMG activity, beginning 50 ± 47 min after release of the occluder. This seizure activity continued for 24-36 h. This study shows that 60 min of asphyxia associated with suppressed ECoG activity and severe acidosis induced neuronal damage, manifesting as seizure activity, and that this occurred when cerebral oxidative metabolism was reduced to ≤50% of control.     

两种剂量来曲唑与克罗米芬对多囊卵巢综合征患者子宫卵巢血流动力学的影响

目的:探讨2种剂量来曲唑(LE)与克罗米芬(CC)对多囊卵巢综合征(PCOS)患者子宫卵巢血流动力学的影响。方法:2种剂量LE与CC治疗90例PCOS不孕症患者,随机分CC组(A组,n=32,50 mg/d)、低剂量LE组(B组,n=30,2.5 mg/d)和高剂量LE组(C组,n=28,5.0 mg/d)。同时以28例正常育龄妇女作为对照组(D组)。经阴道超声监测子宫卵巢血流的参数,比较排卵率、妊娠率。结果:①LE的2个剂量组子宫卵巢血流均出现类似正常育龄妇女的周期性血流变化;②C组方案治疗PCOS有较高的排卵率和妊娠率。结论:来曲唑改善了PCOS患者的子宫卵巢血流供应,5.0 mg可能有更好的促排卵效果。     

Validation of a Sagittal Section Technique for Measuring Clitoral Blood Flow. Volume Flow: A New Parameter in Clitoral Artery Doppler

BackgroundClitoral artery Doppler has been used as an objective technique to measure changes in genital women response. However, the technique has not been fully validated, and arterial volume flow has never been used as an outcome measure.AimsTo validate the technique clitoral artery Doppler measured in a sagittal section and explore arterial volume flow as a new parameter in clitoral Doppler.MethodsWe examined 90 healthy volunteers by clitoral artery Doppler using the sagittal section approach described by Battaglia et al in 2008. We calculated intraobserver, interobserver, and intraobserver intersession variability and reliability for all Doppler parameters and described and validated arterial volume flow as a new parameter in clitoral artery Doppler.OutcomesWe calculated peak systolic velocity (PSV), time-averaged maximum velocity, time-averaged mean velocity, end-diastolic velocity, pulsatility index, resistance index, and volume flow (v-flow) in all groups. We conducted reliability analyses using the intraclass correlation coefficient for agreement. We explored differences between and within observers and calculated agreement limits using the Bland-Altman test.ResultsThe intraclass correlation coefficient analysis showed correlation values higher than 0.75 (good reliability) for most of the variables and higher than 0.60 (moderate reliability) for the remaining ones. There were statistically significant differences between PSV and time-averaged maximum velocity in the intraobserver intersession measurements. For the remaining groups and variables, no statistically significant differences were observed. Bland-Altman analyses showed that the limits of agreement were acceptable and the regressions were not significant. The v-flow parameter also showed good reliability and low variability between groups.Clinical ImplicationsWe found that PSV was not a good outcome measure because of its high intraobserver and intersession variability. Moreover, it is possible to measure v-flow in the clitoral artery using the sagittal technique described by Battaglia et al, and it seems that this measure is reliable and reproducible. This could be the best parameter to assess clinical changes.Strengths & LimitationsThis study provided full validation of the sagittal section approach and of a new parameter, v-flow, which could beuseful for assessing clitoral blood flow. The main limitation of the study is its retrospective nature for validating v-flow.ConclusionWe found that clitoral artery Doppler measured using a sagittal approach is a valid and reliable technique for studying clitoral blood flow in women. The v-flow variable is a promising and reliable parameter for measuring changes in clitoral blood flow.Pérez MF, Agís IF, La Calle Marcos P, et al. Validation of a Sagittal Section Technique for Measuring Clitoral Blood Flow: Volume Flow – A New Parameter in Clitoral Artery Doppler. J Sex Med 2020;17:1109–1117.     

妊娠早期子宫动脉血流的变化及其对妊娠结局的影响

目的:探讨妊娠早期子宫动脉血流的变化及其对妊娠结局的影响。方法:对1 87例妊娠妇女在孕10周、20周和30周分别监测子宫动脉血流动力学参数搏动指数(PI)、阻力指数(RI)和收缩期峰值流速/舒张末期流速(S/D)。结果:157例正常妊娠组孕早期的子宫动脉RI、PI和S/D值和子宫动脉舒张早期切迹数均低于不良妊娠结局组(n=30),其差异有显著性。结论:彩色多普勒超声监测子宫动脉血流动力学参数有助于预测和评估妊娠结局。