高原地区妊娠妇女子宫动脉血流及胎儿脐动脉血流变化的研究

目的　探讨高原环境对正常妊娠妇女子宫动脉血流及胎儿脐动脉血流变化的影响。方法　应用彩色多普勒超声诊断仪 ,测定高原地区 34例妊娠妇女和 37例非妊娠妇女的子宫动脉血流及 119例胎儿脐动脉血流参数 [收缩期与舒张期 (S/D)比值、阻力指数、子宫动脉内径、血流速度、血流量 ];并以平原地区妊娠及非妊娠妇女子宫动脉血流及胎儿脐动脉血流参数作对照。结果　高原及平原地区妊娠妇女的子宫动脉内径、血流量均有增加。高原地区妊娠妇女子宫动脉内径为 (0 35±0 0 4)cm、血流量为 (2 80± 48)ml/min ;平原地区妊娠妇女子宫动脉内径为 (0 45± 0 0 4)cm ,血流量为(4 2 5± 5 5 )ml/min ,两者比较 ,差异有极显著性 (P <0 0 1)。高原地区不同孕期的胎儿脐动脉血流速度、S/D比值、阻力指数均明显高于平原地区 ,两者比较 ,差异有极显著性 (P <0 0 1)。结论　高原环境对子宫动脉血流和脐血流均有一定影响 ,从而导致胎盘血流灌注减少。     

正常妊娠和妊娠期高血压疾病孕妇子宫动脉及其胎儿脐动脉血流动态变化规律的多中心研究

目的 探讨正常妊娠妇女和妊娠期高血压疾病(HDP)孕妇妊娠早、中、晚期子宫动脉及其胎儿脐动脉血流动态变化的规律.方法 选择2005年4月-2006年7月在四川大学华西第二医院、南京医科大学第一附属医院、首都医科大学附属北京妇产医院、华中科技大学同济医学院附属协和医院和上海交通大学医学院附属仁济医院,行产前检查的正常单胎孕妇1098例,平均年龄(28.3±3.3)岁.在妊娠早期(10～14周)、妊娠中期(20～26周)、妊娠晚期(30～36周)采用彩色多普勒超声(彩超)检测孕妇子宫动脉及其胎儿脐动脉的搏动指数(PI)、阻力指数(RI)和脐动脉收缩压最大血流速度(S)与舒张末期最大血流速度(D)比值(S/D).在孕期发生HDP的孕妇为HDP组,未发生HDP的孕妇为正常妊娠组.结果 (1)HDP发生率:1098例孕妇中,正常妊娠分娩者1054例(正常妊娠组),发生HDP44例(HDP组,其中妊娠期高血压20例,轻度子痫前期15例,重度子痫前期9例),发生率为4.01%(44/1098).(2)子宫动脉血流动态变化:正常妊娠组妊娠早、中、晚期孕妇子宫动脉RI分别为0.64、0.57及0.50,PI分别为1.24、0.98及0.80,S/D分别为3.26、2.58及2.20,3项指标随妊娠进展而逐渐降低,妊娠早、中、晚期分别比较,差异均有统计学意义(P<0.01).HDP组妊娠早、中、晚期孕妇子宫动脉RI分别为0.55、0.67及0.64,PI分别为1.22、1.36及1.20,S/D分别为3.18、3.41及3.05,3项指标中孕中期最高,妊娠早、中、晚期分别比较,差异均有统计学意义(P<0.01).HDP组孕妇妊娠中、晚期子宫动脉RI、PI及S/D均高于正常妊娠组,两组比较,差异有统计学意义(P<0.01).(3)胎儿脐动脉血流动态变化:正常妊娠组妊娠中、晚期胎儿脐动脉RI分别为0.71及0.58,PI分别为1. 16及0.87,S/D分别为3.58及2.48,3项指标随妊娠进展而逐渐降低,妊娠中期与晚期比较,差异有统计学意义(P<0.01).HDP组妊娠中、晚期胎儿脐动脉RI分别为0.71及0.63,PI分别为1.20及0.95,S/D分别为3.71及2.69,3项指标随妊娠进展虽有逐渐降低趋势,但与正常妊娠组比较,差异无统计学意义(P>0.05).结论 随着妊娠进展,正常妊娠妇女子宫动脉的血流阻力逐渐下降,舒张末期血流增加;而HDP孕妇随妊娠进展子宫动脉的血流阻力明显升高;正常妊娠妇女和HDP孕妇随妊娠进展其胎儿脐动脉血流阻力均明显下降.     

脐血管彩色多普勒84例临床分析

本文报道了84例胎儿脐血管彩色多普勒血流显像(CDFI)结果,测定了脐动脉脉冲多普勒收缩期平均最大速度与舒张期平均最大速度比值(V_S/V_D).64例正常脐动脉V_S/V_D 表现随孕周增大而逐渐减小,提示血流阻力减低,胎盘血流量增加,以利用于胎儿生长发育需要;5例妊高征和1例妊娠合并高血压V_S/V_D 异常升高,提示血流阻力升高,胎盘血流量减少.说明V_S/V_D 是评价胎盘功能的敏感指标;CDFI 于于产前确诊14例脐带绕颈均经分娩证实.脐带CDFI 及测定脐动脉血流频谱V_S/V_D,对胎儿宫内监护,估测胎盘功能等均有较高的临床应用价值.     

肝素改善妊娠中晚期脐动脉血流异常的临床效果

目的评价肝素对改善妊娠中晚期脐动脉收缩期最大血流速度(S)与舒张末期血流速度(D)的比值异常的临床效果。方法将脐动脉血流S/D比值大于相应孕周的第95百分位以上的67例妊娠中晚期妇女共72例胎儿(5例双胎)分为研究组35例孕妇(38例胎儿),对照组32例孕妇(34例胎儿),知情同意后,研究组用肝素6250U或12500U+5%葡萄糖500ml、静脉滴注,4~6h内滴完,每天1次,平均治疗(37±21)d,范围1~10d;对照组应用低分子右旋糖酐500ml,丹参30ml+10%葡萄糖500ml,东莨菪碱20mg+10%葡萄糖500ml,静脉滴注,每天1次,平均治疗(67±28)d,范围3~14d。定期复查脐动脉血流S/D比值(3~5d1次,严重者每天1次)。结果研究组平均每天脐动脉血流S/D比值下降037,对照组平均每天脐动脉血流S/D比值下降014,两组研究结果比较,差异有统计学意义(P<005)。研究组所需治疗时间显著短于对照组,两组比较,差异也有统计学意义(P<001)。对照组中有10例胎儿脐动脉血流S/D比值进行性升高,2例胎儿脐动脉血流S/D比值出现无穷大,即舒张末期缺如而致胎儿死亡。结论肝素治疗妊娠中晚期脐动脉血流S/D比值异常升高,效果显著,疗程更短。     

胎儿晚期减速的脐动、静脉血流速度的变化

尽管多普勒测胎儿血流已做为孕期监测胎儿的一种方法,但很少有关于分娩过程中胎儿血流速度测定及研究的报告。对20例胎儿(10例正常胎心率,10例胎心有晚期减速)临产后的脐动静脉多普勒血流速度波进行研究,并测定脐动脉收缩期/舒张期血流速度比(S/D)及检测有无脐静脉搏动,结果表明,宫缩间及宫缩时的脐动脉血流S/D,正常胎心组无明显变化(1.56±0.27与1.49±0.21;P=0.35),而胎心晚期减速(简称晚减)组亦无明显变化(2.43±0.74与2.47±0.96;P=0.74)。胎心晚减组的脐动脉     

硝酸甘油用于妊娠高血压综合征治疗的研究

目的探讨硝酸甘油在妊娠高血压综合征（妊高征）治疗中的应用价值及其可行性。方法选择中、重度妊高征患者34例;其中单纯用硫酸镁治疗11例（硫酸镁组）,单纯用硝酸甘油治疗11例（硝酸甘油组）,硫酸镁+硝酸甘油联合用药治疗12例（联合用药组）。另选取正常晚期妊娠妇女11例(正常妊娠组)作对照。采用免疫组织化学及图像分析仪测定以上4组产妇胎盘的内皮型一氧化氮合酶（eNOS）含量,血小板聚集仪检测血小板聚集率,彩色多普勒超声检测应用硝酸甘油后脐动脉收缩期及舒张期（S/D）比值和阻力指数,并记录各组应用药物后的血压变化。结果（1）胎盘eNOS含量硫酸镁组为0.24±0.07,硝酸甘油组为0.25±0.08,联合用药组为0.26±0.07,正常妊娠组为0.35±0.08。妊高征各组与正常妊娠组比较,差异均有极显著性(P<0.01)。（2）硝酸甘油组用药后,脐动脉S/D比值及阻力指数较用药前明显降低,用药前后比较,差异有显著性(P<0.05)。（3）血小板聚集率硝酸甘油组、联合用药组用药后明显降低,用药前后比较,差异有极显著性(P<0.01);硫酸镁组则无明显改变。（4）降压作用硫酸镁组用药后,血压变化不明显;硝酸甘油组及联合用药组,用药后血压降低,用药前后比较,差异有显著性(P<0.05)。结论硝酸甘油有抑制血小板聚集、降低胎儿-胎盘循环阻力及降低血压的作用。能改善妊高征患者的病理状态,从而对妊高征引起的胎儿宫内生长迟缓有治疗作用。     

用彩色超声仪与多功能多普勒仪监测胎儿脐血流S/D值的比较

胎儿脐动脉血流速度波形是反映胎儿－胎盘循环状态的指标之一,当胎儿脐动脉血流出现阻断或逆流的异常波形时,反映胎儿－胎盘循环血流量严重不足;血流阻力指标极度升高表明胎儿宫内缺血、缺氧严重,在胎儿脐动脉逆流波形出现时有４０％～５０％的围产儿死亡,及时终止妊...     

过期妊娠羊水过少是胎儿血流再分布所致吗?

羊水过少是过期妊娠的常见现象。应用彩色多普勒检测57例过期妊娠(>41周妊娠)患者胎儿大脑中动脉、肾动脉和脐动脉的阻力指数,并用超声检查羊水指数对羊水量进行半定量检测,以探讨过期妊娠羊水过少患者脐血流及胎儿血流是否与羊水量正常者不同。 本研究中羊水过少(羊水指数<5cm)15例为研究组,羊水量正常者42例为对照组。结果羊水过少组三种阻力指数值及其比值与对照组无显著差异(两组脐动脉、大脑中动脉和肾动脉阻力指数分别为0.51±0.1对0.52±0.06、0.63±0.1对0.64±0.08、0.71±0.08对0.73±0.05);而新生儿平均出生体重明显低于对照组(分别为3297±438g和3742±448g,P相似文献   

正常妊娠和妊娠期合并急性肾损伤孕妇子宫动脉及胎儿脐动脉血流动态变化规律对妊娠结局的影响

目的:观察正常妊娠妇女和妊娠期合并急性肾损伤(AKI)孕妇子宫动脉及其胎儿脐动脉血流动态变化规律及妊娠结局的差异。方法选择2006年1月-2011年3月笔者所在医院收治的孕妇3553例,在孕期确诊为急性肾损伤的孕妇为急性肾损伤组,孕期未发生急性肾损伤的孕妇为正常妊娠组。采用彩色多普勒超声(彩超)检测孕妇子宫动脉和脐动脉血流动力学变化,并观察其妊娠结局。结果 3553例孕妇中共诊断AKI孕妇85例,发病率为2.39%。不同孕周AKI组孕妇子宫动脉和脐动脉的S/D值、阻力指数(RI)、搏动指数(PI)和子宫动脉舒张早期切迹均显著高于同期正常妊娠组(p<0.05)。两组孕妇妊娠结局有统计学差异(P<0.05)结论子宫动脉和脐动脉血流动力学指标作为一种无创检查方法,对AKI孕妇不良妊娠结局的预测有极大应用价值。     

催产素激惹试验中胎儿脐动脉血流变化及其临床意义

目的　研究催产素激惹试验 (oxytocin challenge test,OCT)在脐动脉血流异常的高危妊娠中应用价值 ,及 OCT试验中同时行脐动脉血流检测的临床意义。　方法　对 170例脐动脉血管阻力增加但仍有舒张期前进血流的患者及 178例脐动脉血流正常的患者行 OCT试验 ,同时于 OCT试验中子宫收缩时和收缩间歇进行脐动脉血流检测。对于 OCT中子宫收缩时脐动脉血管阻力增加>0 .5的阳性 OCT患者于当日行剖宫产终止妊娠 ,余者试行阴道分娩。　结果　在脐动脉血流异常组和正常组 ,阳性 OCT发生率分别为 4 5 .3%和 10 .1% ,差异有显著性 (P<0 .0 0 1) ,伴子宫收缩时脐动脉血流增高 >0 .5的阳性 OCT发生率分别为 37.4 %和 6 .7% ,差异有显著性 (P<0 .0 0 1) ;对于 19例 OCT中没有脐动脉血流增高的阳性 OCT者 ,15例成功阴道分娩。在阴性 OCT组共有 30例患者在分娩过程中因胎儿宫内窘迫进行了手术产 (ODFD) ,其中 2 4例患者 OCT中子宫收缩时脐动脉血管阻力增加 >0 .5。对于不良围产期结果患者 ,78.6 %～ 81.8%发生于 ODFD患者。　结论　 OCT结合脐动脉血流检测对弥补 OCT假阳性和假阴性不足、筛选潜在宫内缺氧的脐动脉血流异常高危儿和改善围产期预后有重要临床价值。     

Maternal plasma glucose at high altitude

Objective To compare plasma glucose in pregnant women living at very high altitude; pregnant women living at sea level; non-pregnant women living at very high altitude; and non-pregnant women living at sea level.
Design sectional study.
Participants Ninety-four pregnant women attending for routine antenatal care at 8–42 weeks of gestation in Cerro de Pasco, Peru which is situated 4370 m above sea level; 122 pregnant women in Lima, which is at sea level; 22 non-pregnant women in Cerro de Pasco; and 31 non-pregnant women in Lima.
Methods Plasma glucose concentrations were measured in samples obtained from the antecubital vein between 8 am and 10 am after an overnight period of fasting for at least 10 hours.
Results Fasting plasma glucose was lower in women at high altitude than in those at sea level, and in both groups the level was lower in pregnant women than in non-pregnant controls. The body mass index was not significantly different between all four groups, and it did not have a significant independent contribution in explaining the variance in fasting plasma glucose.
Conclusion Women native at high altitude have lower plasma glucose concentrations before and during pregnancy than those at sea level.     

Blood gases in pregnancy at sea level and at high altitude

Objective 1. To measure blood gases and minute ventilation in healthy women with normal pregnancies, compare with non-pregnant women both at sea level and at high altitude; 2. to relate the results at altitude with duration of residence there.
Design Cross-sectional study.
Setting Antenatal clinics at sea level in Lima, Peru and at high altitude 4300m in Cerro de Pasco, Peru.
Population A total of 304 normal pregnant women between 7 and 41 weeks of gestation were studied, including 112 who lived at sea level and 192 at high altitude (4300m). For comparison 38 non-pregnant women (19 at sea level and 19 at high altitude) were also studied.
Methods Arterialised blood gases, haemoglobin, pulse oximetry and minute ventilation were measured once in each woman.
Main outcome measures  PO₂, PCO₂, pH  , haemoglobin, oxygen saturation, arterial oxygen content and minute ventilation and their relationship to gestation.
Results PO₂, PCO₂, bicarbonate, base excess and oxygen saturation were lower in pregnancies at high altitude compared with sea level; pH, haemoglobin, arterial oxygen content and minute ventilation were higher. At high altitude oxygen saturation and haemoglobin decreased towards term resulting in a fall in arterial oxygen content at the end of pregnancy. Women whose family had lived at high altitude for at least three generations maintained their oxygenation throughout pregnancy better than women whose family had lived there for less than three generations.
Conclusions In pregnancy at high altitude maternal adaptation appeared adequate in the first trimester but declined towards term. However, maternal oxygenation was maintained in those whose family had lived longest at high altitude suggesting a beneficial adaptation to a hypoxic environment, occurring over generations.     

Respiratory function in pregnancy at sea level and at high altitude

Objective   To determine the effect of pregnancy on respiratory function in a non-Caucasian group and determine whether there was an interaction between pregnancy and altitude of residence.
Design   Prospective cross sectional study.
Setting   Antenatal clinics in Peru, at sea level in Lima and at high altitude in Cerro de Pasco.
Sample   Peruvian women with singleton pregnancies; 122 living at sea level and 192 living at 4300 m altitude in the Peruvian Andes. At each location, 19 non-pregnant women were also studied.
Methods   Respiratory function was measured in pregnant and non-pregnant women living at sea level and at 4300 m.
Main outcome measures   Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEFR), total lung capacity (TLC), inspiratory capacity (IC), residual volume (RV), expiratory residual volume (ERV) and functional residual capacity (FRC).
Results   At sea level, RV and TLC were higher in the third compared with the first trimester ( P < 0.05). At high altitude, FEV1 ( P < 0.01), ERV ( P < 0.01) and FRC ( P < 0.01) were lower in the third compared with the first trimester. Pregnant and non-pregnant women at high altitude were 4 cm shorter ( P < 0.0001) and had larger lung volumes ( P < 0.01); their total lung capacities were approximately 1 L greater than women living at sea level ( P < 0.0001).
Conclusion   These results suggest that the effect of pregnancy on the respiratory function of healthy women is influenced by altitude of residence.     

Stillbirth rates in Peruvian populations at high altitude

OBJECTIVE: To compare the stillbirth rates in 4 cities at different altitudes in Peru. METHODS: The stillbirth rates from a sample of 22,662 births recorded in the Perinatal Information System database were analyzed between 2005 and 2006 for the cities of Lima (150 m), Huancayo (3280 m), Cuzco (3430 m), and Puno (3850 m). RESULTS: Stillbirths were higher at high altitude (>3000 m) (OR 4.82; CI, 3.05-7.72) compared with low altitude. The effect of altitude was observed after controlling for socioeconomic (OR 4.29; CI, 2.61-6.93), demographic and biological (OR 4.18; CI, 2.65-6.77), maternal health care (OR 4.72; CI, 2.96-7.61), and fetal factors (OR 3.96; CI, 2.48-6.45). Inhabitants from the southern Andes demonstrated a protective effect on stillbirth rate compared with the central Andes, which may be due to an ancestry effect with longer multigenerational residence in the southern Andes population. CONCLUSION: Stillbirth rate is higher at high altitude compared with low altitude.     

Pregnancy at high altitude: a hyperviscosity state

BACKGROUND: Pregnancy at high altitude has been associated with intrauterine growth restriction and preeclampsia. These conditions, at sea level, have been linked to increased hematocrit and blood viscosity. The aim of this study was to investigate the effect of high altitude on maternal hemorheology. METHODS: This was a cross-sectional study. We examined 94 pregnant women at 10-38 weeks of gestation resident at high altitude (4370 m above sea level) and 75 at sea level, and 24 and 17 nonpregnant women at each altitude, respectively. Blood and plasma viscosity, hematocrit, plasma fibrinogen, albumin and total protein concentrations were determined in blood samples obtained after an overnight period of fasting. RESULTS: Pregnancy at high altitude, compared to sea level, is characterized by higher hematocrit, blood viscosity (at high shear rate), plasma viscosity, total protein and fibrinogen concentrations (25%, 38%, 7%, 13.3% and 25%, respectively) and 6% lower albumin concentration. Nonpregnant women at high altitude, compared to sea level, had higher hematocrits, blood viscosity, plasma viscosity, total protein and fibrinogen concentrations (25%, 55%, 18%, 26% and 98%, respectively) and 13% lower albumin concentration. CONCLUSION: Pregnancy at high altitude compared to sea level is characterized by increased blood viscosity as a result of increased hematocrit and plasma viscosity.     

Maternal cardiac function during pregnancy at high altitude

OBJECTIVE: To investigate the maternal cardiovascular adaptation in pregnancy at high altitude, compared with that at sea level. DESIGN: Cross sectional study. SETTING: Two maternity units providing routine antenatal care: one at 4370 m above sea level (Cerro de Pasco, Peru) and one at sea level (Lima, Peru). POPULATION: We examined 175 pregnant women at 5-41 weeks of gestation and 16 non-pregnant controls resident at high altitude and 132 pregnant women and 18 non-pregnant controls at sea level. METHODS: Two-dimensional and M-mode echocardiography of the left ventricle. MAIN OUTCOME MEASURES: Maternal cardiac output and left ventricular longitudinal and transverse systolic function indices. RESULTS: Pregnancy at high altitude, compared with sea level, is associated with 11% lower birthweight and 31% lower maternal cardiac output, due to 15% lower stroke volume and 11% lower heart rate. The lower stroke volume was due to a lower preload and impaired longitudinal and transverse left ventricular systolic function. Mean arterial pressure was about 8% lower during pregnancy at high altitude versus sea level. Pregnant women at high altitude failed to expand their intravascular space to the same extent as the sea level group: cardiac output increased by 17%, left atrial diameter by 12% and end-diastolic diameter by 1% at high altitude versus 41%, 25% and 5%, respectively, at sea level. CONCLUSIONS: Pregnancy at high altitude, compared with sea level, is characterised by lower cardiac output due to lower heart rate and lower stroke volume and reduced expansion of the maternal intravascular space compared with the non-pregnant state.     

Maca extracts and estrogen replacement therapy in ovariectomized rats exposed at high altitude

PurposeHormone Replacement Therapy (HRT) and herbal remedies are often used to alleviate menopausal symptoms, but their effects and efficacy at high altitudes presents with several uncertainties. The purpose of this study was to evaluate whether pre‐treatment with maca (Lepidium meyenii Walp) improved the tolerance to high altitude on an ovariectomized (OVX) rat model at sea level.MethodThe animals were treated with 17β‐estradiol (200 µg/kg; E2), red and black maca (1.5 g/kg) for 28 days and exposed at high altitude or sea level.ResultOur findings showed that red and black maca extracts significantly (P < .001) reduced the MDA level in OVX rat serum under hypoxia in a similar way to E2. Red and black maca extracts had similar effects with E2, by significantly (P < .001) reversing and increasing the ovariectomized induced decrease in cornified endometrial cell number. Under hypoxic conditions, the black maca (P < .05) and E2 (P < .01) increased the uterine weight in OVX rats. Finally, E2 alone significantly recovered the frequency of the uterine contractile response.ConclusionAqueous extract of L. meyenii partially protects the reproductive function in hypobaric hypoxic environment, through the recovery of the cornified endometrial cells and uterine weight in a menopausal model of OVX rats.