The predictive value of uterine artery blood flow measurements for uterine receptivity in an intracytoplasmic sperm injection program

OBJECTIVE: To assess whether uterine artery blood flow impedance, measured as the pulsatility index on the day of ET in patients undergoing IVF-ET with microinjection, can predict the likelihood of pregnancy. DESIGN: Prospective clinical study. SETTING: A tertiary referral center for assisted reproduction. PATIENT(S): Seventy patients undergoing intracytoplasmic sperm injection (ICSI) for andrologic indications. INTERVENTION(S): Transvaginal color Doppler examination performed on the day of ET. MAIN OUTCOME MEASURE(S): Mean (+/- SD) pulsatility index value of the left and right uterine arteries, serum E2 levels, implantation rates, and ongoing pregnancy rates (PRs). RESULT(S): The patients were divided into pregnant and nonpregnant groups and were separated according to whether the pulsatility index was low (1.00-1.99), medium (2.00-2.99), or high (> or = 3.00). The pulsatility index values did not change statistically in the pregnant and nonpregnant groups. The implantation rates were 19.5%, 15.4%, and 25% for the low-, medium-, and high-pulsatility index groups, respectively. The ongoing PRs for the same groups were 35.3%, 26.7%, and 37.5%, respectively. CONCLUSION(S): The study suggests that blood flow, measured as the pulsatility index on the day of ET, cannot predict the likelihood of pregnancy in stimulated cycles of ICSI.     

The direct effects of circulating lidocaine on uterine blood flow and foetal well-being in the pregnant ewe

We infused lidocaine intravenously into 13 pregnant ewes at a rate sufficient to maintain plasma levels between 2-4 mugm/ml, which are those commonly seen with regional anaesthesia. These levels did not change maternal blood pressure, pulse rate, cardiac output, stroke volume, total peripheral resistance, uterine blood flow or intra-amniotic pressure. Foetal blood pressure and pulse rate remained stable as did both maternal and foetal blood gases and acid-base values.     

The effect of diazoxide on uterine blood flow in pregnant sheep

Diazoxide, a labor inhibiting agent, was administered intravenously at various rates to seven pregnant, near-term sheep to evaluate its effect on cardiovascular and uterine hemodynamics. Uterine blood flow was measured with electromagnetic flow transducers. Rapid administration of diazoxide resulted in a profound maternal tachycardia with hypotension, an increase in uterine vascular resistance, and a significant decrease in uterine blood flow. With slow infusion of the drug, the changes in heart rate and blood pressure were minimized, uterine vascular resistance was decreased, and uterine blood flow was maintained. Therefore, slow infusion appears to be the preferred method for inhibiting labor with diazoxide.     

Significance of a diastolic notch in the uterine artery flow velocity waveform induced by uterine embolisation in the pregnant ewe

OBJECTIVE: To determine whether water exposure causes middle ear contamination in patients with collar button tympanostomy tubes (TTs). METHOD AND DESIGN: An in vitro model of a human head that contained an auricle, external auditory canal, tympanic membrane with TT, middle ear, eustachian tube, and mastoid cavity was developed. Two electrodes connected to an external ohmmeter resided in the middle ear to detect water entry. The model was tested with 4 types of water exposure: showering, bathing, hair rinsing, and swimming. Statistical analysis was performed by the Fisher exact test. MAIN OUTCOME MEASURES: A positive test result corresponded to water entering the middle ear via the TT, confirmed by a resistance reading of zero on the ohmmeter. A negative test result indicated no change in the initial high resistance reading. RESULTS: No positive test results were obtained for showering (0 of 60 tests), hair rinsing (0 of 60 tests), or head submersion (12.7 cm) in clean tap water (0 of 60 tests). Ten positive test results were obtained for head submersion in soapy water (10 of 97 tests), which was statistically different from clean water (P< or =.007). Swimming pool depths of 30, 45, 60, and 75 cm elicited positive test results in 2 of 16, 3 of 18, 2 of 20, and 11 of 20 tests, respectively. A higher incidence of water entry into the middle ear occurred at depths of more than 60 cm (P< or =.001). No statistical difference between depths of 60 cm or less occurred (P= .88). CONCLUSIONS: Showering, hair rinsing, and head submersion in clean tap water do not promote water entry into the middle ear. Submersion in soapy water increases the probability of water contamination. Pool water infrequently enters the middle ear with head submersion, but the incidence increases with deeper swimming (>60 cm). These data provide further evidence that many water precautions frequently advised in patients with TTs are unnecessary.     

The effects of sevoflurane on cerebral blood flow autoregulation in rats

In all species tested, except humans, biological differences between vitamins D2 and D3 are accepted as fact. To test the presumption of equivalence in humans, we compared the ability of equal molar quantities of vitamin D2 or D3 to increase serum 25-hydroxyvitamin D [25(OH)D], the measure of vitamin D nutrition. Subjects took 260 nmol (approximately 4000 IU) vitamin D2 (n=17) or vitamin D3 (n=55) daily for 14 d. 25(OH)D was assayed with a method that detects both the vitamin D2 and D3 forms. With vitamin D3, mean (+/-SD) serum 25(OH)D increased from 41.3+/-17.7 nmol/L before to 64.6+/-17.2 nmol/L after treatment. With vitamin D2, the 25(OH)D concentration went from 43.7+/-17.7 nmol/L before to 57.4+/-13.0 nmol/L after. The increase in 25(OH)D with vitamin D3 was 23.3+/-15.7 nmol/L, or 1.7 times the increase obtained with vitamin D2 (13.7+/-11.4 nmol/L; P=0.03). There was an inverse relation between the increase in 25(OH)D and the initial 25(OH)D concentration. The lowest 2 tertiles for basal 25(OH)D showed larger increases in 25(OH)D: 30.6 and 25.5 nmol/L, respectively, for the first and second tertiles. In the highest tertile [25(OH)D >49 nmol/L] the mean increase in 25(OH)D was 13.3 nmol/L (P < 0.03 for comparison with each lower tertile). Although the 1.7-times greater efficacy for vitamin D3 shown here may seem small, it is more than what others have shown for 25(OH)D increases when comparing 2-fold differences in vitamin D3 dose. The assumption that vitamins D2 and D3 have equal nutritional value is probably wrong and should be reconsidered.     

Effect of dehydroepiandrosterone sulfate on uterine artery flow velocity waveforms in term pregnancy

OBJECTIVE: To investigate the interrelation between estrogen synthesis by the fetoplacental unit and uteroplacental hemodynamics in term pregnancy. METHODS: Transvaginal color Doppler flow imaging and pulsed Doppler ultrasonographic assessments were made on ten normal full-term pregnant women before and 3, 5, 10, 30, and 60 minutes after the administration of a 200-mg intravenous dose of dehydroepiandrosterone sulfate (DHAS) in 20 mL of 5% dextrose. Ten normal full-term pregnant women received 20 mL of 5% dextrose as controls. The pulsatility index (PI) values for the uterine artery, heart rate, and mean arterial pressure were recorded. Plasma estradiol (E2) was measured before and 10 minutes after the infusion. RESULTS: In the DHAS group, uterine artery PI decreased from baseline by 26% (P < .05) after 5 minutes, and the mean reduction was 36% (P < .05) after 10 minutes and 15% (P < .05) after 30 minutes. The PI returned to the baseline value 60 minutes later. In the control group, there was no change in uterine artery PI. No change was found in heart rate or mean arterial blood pressure in the control or DHAS groups. The mean plasma E2 increased from 22.3 +/- 6.6 to 56.2 +/- 24.1 ng/mL (P < .05) 10 minutes after the infusion in DHAS subjects, whereas there was no significant change in plasma E2 in the controls. CONCLUSION: Dehydroepiandrosterone sulfate induces a significant decrease in the uterine artery PI, which suggests a possible decrease in uterine vascular impedance in term pregnancy.     

Effects of Cis- and trans-clomiphene on the uterine blood flow of oophorectomized ewes

Changes in the left uterine artery blood flow (YBF) after intraarterial administration of estradiol-17beta and cis- and trans-clomiphene citrate to conscious, oophorectomized ewes were monitored by chronically implanted electromagnetic flow probes. Cis-clomiphene produced UBF increases comparable to or greater than those produced by estradiol-17beta but at dose levels 20 times greater. Comparison of UBF response curves for cis-clomiphene with those for estradiol-17beta showed a delayed onset of initial vasodilation and a delayed peak response. The duration of uterine vasodilation produced by cis-clomiphene was dose-dependent and exceeded that produced by estradiol-17beta. Similar reponses were observed with trans-clomiphene but at dose levels at least 1,000 times those of estradiol-17beta. The characteristics of clomiphene-induced UBF responses that differed from those after estradiol-17beta may reflect differences in estrogen receptor activation between the compounds.     

Detection of human chorionic gonadotropin in blood of regularly bleeding women using copper intrauterine contraceptive devices

Highly sensitive and specific radioreceptorassay and radioimmunoassay of human chorionic gonadtropin (hCG) have been used in the detection of hCG in random serum samples during the luteal phase of the menstrual cycles of 200 women and in daily serum samples obtained a few days prior to expected ovulation through the luteal phase in 3 women with regular bleeding patterns and using a copper intrauterine device (IUD). Twelve to nineteen per cent of IUD users showed hCG in serum during the luteal phase, indicating that the presence of the IUD, while permitting fertilization, probably causes interference through degeneration of the blastocyst and consequent lack of implantation.     

The effects of flunarizine and pentoxifylline on vestibular blood flow in the guinea pig

Several authors have proposed that complications arising from vestibular disorders are the result of compromised circulation. The purpose of the current study was to assess the ability of flunarizine and pentoxifylline to increase peripheral vestibular blood flow (VBF), since flunarizine is a selective calcium-channel entry blocker that inhibits calcium-related contraction of smooth muscle, while pentoxifylline is a xanthine derivative that promotes microcirculation by affecting red blood cell malleability. Both of these treatment strategies have received considerable attention in clinics and laboratory, but their effects on blood flow are unclear. Changes in VBF were evaluated from the posterior semicircular canal ampulla in guinea pigs using a laser Doppler flowmeter. One group of animals was infused with pentoxifylline at concentrations of 10-40 mg/ml, while a second group was treated with 0.3-1.5 mg/kg flunarizine. VBF, blood pressure (BP) and heart rate (HR) were monitored continuously. Findings showed that pentoxifylline induced a concentration-dependent increase in VBF. In contrast, no increase in VBF occurred in response to flunarizine infusions. These studies suggest that the effectiveness of pentoxifylline in the clinical treatment of vestibular disorders may be the result of improved blood flow.     

Superior mesenteric artery blood flow in celiac disease

Measurements of the hemodynamic parameters of the superior mesenteric artery were performed in 18 patients with celiac disease. Ten were studied at the time of diagnosis, when a small bowel biopsy showed a flat mucosa. The remaining eight patients were studied after complete clinical and histological recovery induced by a gluten-free diet. Doppler ultrasound flowmetry was used to measure blood flow in physiological and fasting conditions and after a mixed liquid test meal (Ensure-Plus). The results were compared with those of healthy subjects (N = 7). Mean basal flow was 50% higher in untreated celiac disease patients than in healthy controls and patients with chronic pancreatitis (P = NS). Postprandial mesenteric blood flow was significantly increased (P < 0.002) and delayed in time (P < 0.005) in celiac disease as compared to controls. Successful treatment reduced the mesenteric blood flow in celiac disease to normal values. Our study demonstrates that pathophysiological changes in the small bowel mucosa during the active clinical phase of celiac disease induce an abnormal splanchnic circulation.     

The experimental examination of the effect on the uterine blood flow of angiotensin II during pregnancy (author's transl)

In experiments with animals it was investigated the endurance of the myometrial and the blood flow of the renal cortex during endogenous pressure substances. At the same time it was tested, if treatment with sexual hormones or a pregnancy had the tested principles and changes through pressure substances, and that the changes were significant. The investigations were conducted on three groups of female rabbits. The blood changes in myometrial and in the uterine were measured and continually registered with the special heated thermistor, from the principle of the thermoclearance. The success of the blood pressure was intraarterial measured with an electric mechanism. Precisely the same doses (in relativity of the animals weight) of pressure substances were applied with an infusions pump intravenously. And pressure substances Angiotensin II, Norepinephrine and Epinephrine, and their actions on the blood pressure and blood flow through the myometrium and through the renal cortex were examined. Altogether 131 values were registered. The results of the study that were statistically secure were as follows: a) The uterine blood flow pro tissue volume unit stays constant also by pregnancy or pseudopregnancy. b) The blood flow of the kidney is perhaps twice as high as the myometrial. c) The myometrial blood flow is with the arterial systolic blood pressure tightly correlated. Blood pressure increases through Angiotensin-infusion and also recovery of the uterine blood flow. d) An autoregulation of the uterine blood flow is not observed. e) The decrease of the renal blood flow after the giving of pressure substances was not modified through pregnancy. f) In quality the behaviour of the organ blood flow is the same after applied infusion of the pressure substances. Quantity differences exist however between Angiotensin II, Norepinephrine and Epinephrine. The method of measuring the blood flow through the uterus and in the kidney was placed in one view there. The finding of another examination groups for the problem of the organ blood flow in pregnancy was under critical consideration the methods combined and in connection with the proper examinations discussed. Till now in the theory over the cause of EPH-syndrom the predominate recently compiled comprehensive summary was; the proper body pressure substances--especially from the renin Angiotensin system--after chronical invoices it was decides diminished uterus blood flow appeared. After the earlier results were not all secure. The proper examination speech was therefore, that regarding the kidney function relevant alterations, also unter the conditions of pregnancy, are to be observed. The pressure dependant regulation of myometrial blood flow without proving autoregulation required however another test of the predominante gestose theory.     

Effect of exercise on cardiac output and distribution of uterine blood flow in pregnant ewes

This study was designed to determine what effect physical training has on heart rate and stroke volume responses to exercise stress and to determine if exercise altered the distribution of uterine blood flow. Measurements were made in ten pregnant ewes at rest and immediately following exercise on a treadmill. Five ewes underwent physical training for 3 wk prior to measurement. An increase in heart rate with no change in stroke volume was observed following exercise in both trained and untrained ewes. Total uterine blood flow was not changed following exercise, but distribution was altered in favor of the placenta. Blood flow was evenly distributed within the placenta before and after exercise. The redistribution of flow to the placenta that occurs after exercise. tphe redistribution of flow to the placenta that occurs after exercise might represent a compensatory mechanism for the fetus.     

Drug effects on cerebral blood flow in the baboon model--acetazolamide and nimodipine

The sensitivity of the baboon model under anaesthesia for single photon emission computed tomography (SPECT) of the brain with 99mTc-HMPAO, as recently developed by us to study cerebral blood flow patterns, was investigated using drugs that are known to increase cerebral blood flow, e.g. acetazolamide, the carbonic anhydrase inhibitor and nimodipine, the calcium channel blocker. Increases in cerebral blood flow for both acetazolamide and nimodipine were observed that correspond well with other studies. Statistically significant regional specificity was noted for acetazolamide and nimodipine. Interestingly a combination of these drugs did not enhance cerebral blood flow but rather decreased it in comparison with the individual drug responses. The results were correlated with arterial blood pressure, heart rate, pCO2 and pO2. A blood pressure decrease was noted for both drugs, while acetazolamide had a marked influence on pO2. The results indicate that the baboon model is sensitive for evaluation of drug effects on cerebral blood flow.     

The isolated supported canine heart: a model for the evaluation of drug effects on regional myocardial blood flow

The present investigation was designed to determine the effect of propranolol on regional myocardial blood flow and oxygen consumption (MVO2) in the isolated supported dog heart preparation perfused at a constant coronary blood flow. The transmural distribution of blood flow, determined by the radioactive microsphere technique, was expressed as the epicardial/endocardial blood flow ratio (epi/endo). Propranolol (0.5 mg/kg i.v.) produced a significant decrease in heart rate and myocardial contractile force and an increase in coronary artery perfusion pressure due to an increase in coronary vascular resistance. These hemodynamic changes were accompanied by significant decreases in epi/endo (increased endocardial perfusion) and MVO2. Reduction of perfusion pressure to control by a decrease in total coronary blood flow produced no further change in epi/endo or MVO2. However, increasing heart rate to control increased epi/endo to predrug levels. Contractile force and MVO2 remained reduced below control. Norepinephrine infusion (1 mug/min intracoronary) produced a significant increase in heart rate and contractile force and decrease in perfusion pressure. These changes were accompanied by an increase in epi/endo and MVO2. Propranolol (0.5 mg/kg i.v.) abolished the response to norepinephrine. Propranolol may produce beneficial effects in angina pectoris by a decrease in epi/endo (via a reduction in heart rate) and MVO2 and by beta adrenergic blockade of the deleterious effects of catecholamines.