To determine if oestradiol and progesterone concentrations are related to uterine blood flow in early pregnancy, we measured these hormones at the time of vaginal Doppler ultrasound before and after the beginning of intervillous circulation in spontaneous pregnancy (group I), after clomiphene citrate administration (group II), and after clomiphene citrate ...

The embryonic period of development is characterized by marked variability in the rate of embryonic growth and development. Differences in uterine blood flow may explain this variability. We investigated the relationship between uterine artery blood flow volume (VOL), uterine artery pulsatility index (UA-PI), uterine artery resistance index (UA-RI), spiral artery ...

The aim of the present study was to simulate the pathological uteroplacental circulation observed in complicated human pregnancies in the pregnant ewe and to analyze its velocimetric changes. Four pregnant ewes at 16-17 weeks of pregnancy were used in the study. Micro-beads (Gelfoam) were administered stepwise into the uterine artery ...

The uterine blood flow to individual implantation sites was evaluated in early normal and diabetic rat pregnancy, and related to maternal metabolic state, length of gestation, and embryonic outcome. The aim was to search for a possible coupling between the flow rate and embryonic development. We studied pregnant rats of ...

Uterine blood flow volume has been thought to increase in a linear fashion throughout pregnancy, but previous studies in early pregnancy may have not been performed often enough or in sufficient numbers of patients. We measured uterine artery blood flow volume, average velocity, vessel cross-sectional area, resistance index, and spiral ...

OBJECTIVE: To determine whether color flow pulsed Doppler analysis of corpus luteum blood flow in normal cycles differs from cycles with a luteal phase defect. DESIGN: A prospective study of natural ovarian cycles. SETTING: The University of Vermont Reproductive Endocrinology and Infertility Service. PATIENTS: Ten women with regular menstrual cycles ...

OBJECTIVE: To measure the flow velocity of the ovarian, uterine, radial, and spiral arteries in different age groups. DESIGN: Serial measurements throughout the menstrual cycle in normal cycling women with documented fertility were compared with those in postmenopausal patients with and without hormone replacement therapy (HRT). SETTING: Department of Obstetrics ...

The objective of this study was to correlate, during 12 weeks of therapy with gonadotropin releasing hormone agonist (GnRH-a), the chronological effect and the hemodynamic changes on the uterine artery and the leiomyometrial supplying vessels. Twenty-three premenopausal women with clinically diagnosed uterine leiomyomas received 3.75 mg of leuprolide acetate intramuscularly ...

To evaluate non-invasively the role of levonorgestrel releasing devices in direct contact with the endometrium on menstrual spotting and endometrium inactivation, we inserted levonorgestrel releasing devices (20 micrograms/24 h) either into the cervical canal or the uterine cavity of 30 fertile women. Both before insertion and over the following 3 ...

OBJECTIVE: Our purpose was to investigate whether acute alterations of amniotic fluid volume affect uteroplacental perfusion. STUDY DESIGN: Three groups of patients of comparable gestational age were studied in a fetal medicine referral unit: (1) eight pregnancies with severe polyhydramnios because of twin-twin transfusion syndrome undergoing therapeutic amnioreduction, (2) seven ...

Second trimester assessment of uterine blood flow has been advocated as a predictor of subsequent adverse perinatal outcome. The reproducibility of uterine artery resistance index, as assessed using colour Doppler imaging, was investigated. Two observers, both of whom were experienced in colour Doppler assessment of uterine artery flow velocity waveforms, ...

Blood flow changes in the ovarian stroma of women embarking on in-vitro fertilization treatment were assessed on day 2 or 3 of the menstrual cycle using colour and pulsed Doppler ultrasound. Women were divided into three groups: group 1, 63 women with regular, ovulatory menstrual cycles and normal ovaries on ...

Lines of mice, selected for 21 generations using alternative criteria to increase litter size, were evaluated for uterine mass and uterine blood volume to help explain differences in uterine capacity. For this study, mice were sampled from Generation 27, the sixth generation after relaxation of selection. Mice came from all ...

The aim of this study was to elicit reference data representative of normal findings at transvaginal gray-scale and Doppler ultrasound examination of the uterus and ovaries in postmenopausal women. A total of 144 asymptomatic postmenopausal women with normal findings at clinical gynecological examination were included in the study. They underwent ...

Nine in vitro fertilization (IVF) patients with moderate or severe ovarian hyperstimulation syndrome (OHSS) were recruited for a longitudinal study. Twenty-four unselected, asymptomatic patients undergoing similar IVF treatment were used as controls. OHSS was diagnosed 8-13 days after oocyte retrieval. All subjects were examined with pulsed color Doppler ultrasound. The ...

We used transvaginal color Doppler sonography to study uterine artery blood flow velocity waveforms in 345 normal postmenopausal women who had never been on hormone replacement therapy. Our objective was to establish the standard baseline flow values for normal postmenopausal women. The mean pulsatility index was 3.38 +/- 1.04 and ...

To determine whether uterine blood flow was reduced and indexes of pelvic blood flow distribution altered in normotensive pregnancy at high (3,100 m) compared with low altitude (1,600 m), we measured uterine, common iliac, and external iliac artery blood flow velocities and diameters in women during pregnancy and again postpartum. ...

We used transvaginal color Doppler sonography to study the effect of hormone replacement on the uterine arterial blood flow for 203 postmenopausal women. The regimens studied involved estrogen replacement alone, continuous combined estrogen and progestogen, and estrogen followed sequentially by combined estrogen-progestogen. The mean pulsatility index fell to 65% +/- ...

Uterine artery blood flow was assessed by transvaginal colour and pulsed Doppler ultrasound prospectively in six women during the peri-ovulatory period. All patients had regular ovulatory menstrual cycles and a mid-luteal serum progesterone consistent with spontaneous ovulation in the preceding cycle. Each patient underwent serial transvaginal ultrasound examination and Doppler ...

OBJECTIVE: To determine the effects of induction of multiple ovulation and of luteal P supplementation on the impedance to blood flow in the uterine and intraovarian arteries during the luteal phase. DESIGN: A prospective study using transvaginal color flow Doppler imaging. SETTING: A university-based infertility center. PATIENTS: Fifty-six women with ...

The Doppler flow velocity wave forms originating from the common, external and internal iliac arteries of 20 healthy volunteers were recorded in order to find out if the arteries showed characteristic velocity wave forms. Further questions included whether these flow patterns changed during the ovarian cycle and whether differences between ...

This study examined the in vivo distribution and metabolism of maternal progesterone (P4) in the rat uterus at Day 16 of pregnancy, i.e., the time of maximal P4 secretion, and at Day 22, one day prior to parturition. Arterial and uterine venous blood samples were collected at 20-min intervals from ...

This study was conducted to evaluate endometrial blood flow characteristics in response to estrogen replacement therapy (ERT) and tamoxifen in asymptomatic postmenopausal women, and to correlate the resistance index (RI) with plasma estradiol levels. Transvaginal color Doppler ultrasound examinations were performed in 30 asymptomatic, postmenopausal women who demonstrated thin endometria ...

We investigated for the presence of circadian variation in uterine artery blood flow indices during the late follicular phase of the menstrual cycle. Twenty women with regular menstrual cycles underwent transvaginal color Doppler assessment of blood flow in the uterine arteries on two occasions precisely 12 h apart on the ...

BACKGROUND AND OBJECTIVES: Bolus intravenous injection of epinephrine can decrease uterine blood flow. This study examined the effects of intravenous infusion of epinephrine on uterine blood flow in the gravid ewe. METHODS: Maternal and fetal vascular catheters and a maternal electromagnetic uterine artery flow probe were implanted in 10 near-term ...

The purpose of this study was to investigate the temporal relationship between the early pregnancy peak of circulating human chorionic gonadotrophin (HCG) concentration and the establishment of maternal blood flow in the placental intervillous space. The presence of blood flow echoes within intervillous space was determined by colour Doppler imaging ...

The role of transvaginal pulsed colour Doppler ultrasound in the prediction of the outcome of in-vitro fertilization (IVF) therapy was assessed longitudinally in 30 patients during stimulated cycles. The pulsatility index (PI) of the uterine arteries did not change significantly until the mid-luteal phase. Within 6 days after the beginning ...

OBJECTIVE: To evaluate the endometrial blood flow response to hormone replacement therapy (HRT) in women with premature ovarian failure who plan to enter an oocyte donation program. DESIGN: Transvaginal color Doppler ultrasound examinations were performed in women with ovarian failure before and during a cycle of standard HRT and in ...

The H2 gas clearance technique was employed to measure uterine blood flow (UBF) in ovariectomized rats. A needle-type platinum electrode (125 microns diam) was inserted into the rat uterine wall to measure the tissue blood flow surrounding the electrode. The electrode can be placed in individual layers of the uterus ...

In this study we assessed the variability of measuring uterine artery pulsatility index by colour Doppler ultrasound using different ultrasound transducers (abdominal 3 MHz, abdominal 5 MHz, endovaginal 5 MHz with and without a full bladder). We then assessed the intra-observer coefficient of variation for the different transducers and interobserver ...

Transabdominal Doppler velocity waveform measurements of the uterine arteries during the third stage of labor were performed upon 25 patients with uncomplicated vaginal deliveries and 5 with prolonged third stage in order to further assess third-stage mechanisms. Based on Doppler flow measurements, three phases of the third stage of labor ...

A case of spontaneous luteinized unruptured follicle syndrome is presented with full documentation of hormonal, morphological and haemodynamic changes. Changes in uterine blood flow were also noted. Growth of the leading follicle was slow during the follicular phase of the cycle. After the luteinizing hormone (LH) surge, growth of the ...

The aim of this study was to investigate the presence of nitric oxide synthase (NOS) in human uterus. Tissues were obtained at operation from 10 women undergoing hysterectomy for benign disease. In-situ hybridization was used to determine the distribution of mRNA for NOS with a 483 bp digoxigenin-labelled antisense riboprobe. ...

In pregnancy, the maternal circulating renin-angiotensin system (RAS) and uteroplacental tissue RAS has been thought to support maternal placental flow by raising maternal arterial pressure or changing placental vascular resistance. Also, the placenta or uterus may alter maternal circulating RAS. Recent studies in the authors' laboratory using chronically catheterized rabbits ...

Despite proven efficacy in interrupting uterine smooth muscle contraction for periods of 24-48 h, a recent clinical study concluded that the adrenergic beta-receptor agonist, ritodrine hydrochloride (Yutopar) had significant detrimental side effects. Our previous preclinical studies have shown that ritodrine reduces placental blood flow via a vascular steal phenomenon. Moreover, ...

Twenty-seven women with endometrial cancer were studied with Doppler ultrasound coupled with a vaginal probe. Pulsatility index of the flow velocity of the uterine artery was recorded and compared to that of a control group. The subjects and the controls did not differ in blood flow measurements. There was no ...

Resistance index (RI) and pulsatility index (PI) in the uterine and spiral arteries, uterine artery peak systolic velocity and intervillous blood flow were recorded by transvaginal colour Doppler imaging in 30 missed abortions and 30 normal pregnancies matched for menstrual age. Pathological examination was performed in both groups within 24 ...

Uterine artery blood flow measurements made solely in the recumbent position may miss physiological changes that occur while patients are upright. We evaluated the effect of standing on the minute blood flow volume of the ascending uterine artery, the pulsatility index (PI), resistance index (RI) and waveforms and on the ...

The purpose of this study was to use colour Doppler to determine the effect of epidural anaesthesia on the uterine and umbilical blood flow velocities. After determining the precision of the technique, Doppler insonation of the uterine and umbilical arteries was performed in consenting non-labouring patients requesting epidural anaesthesia for ...

The aim was to obtain data that could be used to determine the most appropriate treatment regimen for uterine fibroids with a gonadotropin releasing hormone analog (goserelin) before surgery. Fifteen premenopausal women (aged 27-53 years; mean 40 years) were referred from a gynecological outpatients' clinic. They all had uterine fibroids ...

Doppler ultrasound is a non-invasive technique for investigating artery blood flow variations. In 39 normoovulatory patients we investigated the correlation between bladder distension and uterine/ovarian blood flow resistance. The patients were scanned transabdominally or transvaginally both with full and emptied bladders. Pulsatility Index was significantly higher in patients with a ...

The effects of two types of uterine displacement, on uterine and umbilical artery blood flow waveforms were investigated in 22 healthy parturients undergoing elective caesarean section. Displacement was accomplished with either a wedge under the right hip or a mechanical displacer plus 5 degrees left lateral tilt of the operating ...

The anatomy of the human uterine vascular tree changes repeatedly with the variations in hormonal state during each menstrual cycle, with progressive differentiation of arterioles up to the premenstrual state. Hormonal factors also influence the innervation of uterine arteries, both cholinergic, adrenergic and peptidergic, and regulate the spontaneous contractile activity ...

Uterine dystocia, often of unknown cause, remains one of the commonest causes of emergency caesarean section. We have tested the hypothesis that small acidic changes in pH, that can occur during labour contractions, can decrease contractions and contribute to dystocia. We simultaneously recorded intracellular pH (pHi) and force in human ...

The effects of location within the left or right uterine horn, position within each uterine horn, and fetal sex on fetal bodymass, blood flow to individual uterine segments associated with fetuses, and blood flow to the maternal portion of the placenta were investigated in rats. Sprague-Dawley rats were anaesthetized on ...

OBJECTIVE: To evaluate the relation between the development of the uteroplacental circulation as assessed by Doppler velocimetry and the maternal blood relaxin concentration. METHODS: Transvaginal color Doppler investigation of the uteroplacental circulation was performed in 42 healthy women at 6-15 weeks' gestation before termination of pregnancy for psychosocial reasons. The ...

OBJECTIVE: To study the effects of low doses of the hormone atrial natriuretic peptide (ANP) on uteroplacental blood flow in patients with preeclampsia. METHODS: Eleven women with preeclampsia were infused intravenously with ANP (10 ng/kg/minute). Uteroplacental blood flow index was measured using dynamic placental scintigraphy with indium-113m. Regional blood flows ...

We used the transvaginal ultrasound examination in women with abnormal uterine bleeding prior to conventional D&C. It is a simple, non-invasive technic, convenient and accepted by all patients. The endometrial thickness of less than 6 mm is compatible with atrophic endometrium, but of more than 17.7 mm will be malignancy. ...

The effects of noradrenaline on the rates of secretion of ovarian progesterone and 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OHP), blood flow and oxygen consumption were examined in rats on day 16 of pregnancy. A modified venous outflow technique was used to infuse noradrenaline directly into the ovary, without recirculation, and to monitor ...

The results of our previous studies suggested that endothelin-1 (ET-1) might be contributory to the impaired uteroplacental blood flow seen in preeclampsia. The aim of this study was to investigate the in vitro influence of isradipine on ET-1-induced contraction of myometrial resistance arteries from pregnant women, as these vessels are ...