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, ...

Uterine artery Doppler examination can identify impaired trophoblast invasion in the second trimester of pregnancy. High resistance and an early diastolic 'notch' show insufficient physiological conversion of the spiral arteries. Uterine artery Doppler is routinely performed between 22-24 weeks which is relatively late for treatment. In this study we wanted ...

OBJECTIVE: To provide individualized risk prediction of severe adverse pregnancy outcome based on uterine artery Doppler screening at 23 weeks. METHODS: Color Doppler assessment of the uterine arteries was carried out in 5121 women attending for routine care at 23 weeks in two inner-city obstetric units. The mean uterine artery ...

OBJECTIVES: To examine changes with time in the fetal renal circulation by Doppler sonography in the severely growth-restricted preterm fetus during the period of gradual deterioration prior to delivery, and to examine the relationship between Doppler measurements, amniotic fluid index, birth weight and fetal condition at birth. METHODS: This was ...

OBJECTIVE: The purpose of this study was to assess the fetal outcome of first-trimester pregnancies with reversed end-diastolic flow in the umbilical artery. STUDY DESIGN: Doppler studies in the umbilical artery were carried out in 2970 consecutive pregnancies scanned at 10 to 14 weeks. RESULTS: We observed 11 (0.4%) cases ...

BACKGROUND: An increased incidence of pregnancy complications following assisted reproduction has been reported. The use of uterine artery Doppler ultrasound may aid the prediction of such complications. METHODS: Doppler was performed at 18-24 weeks gestation in 114 singleton and 32 twin pregnancies after intracytoplasmic sperm injection (ICSI) and compared with ...

PURPOSE: To quantify the tear spreading velocity and stabilization time after blinks in healthy patients. METHODS: Video recordings (magnification, x130) were made of the movements of naturally occurring particles in the tear film while patients blinked naturally. After each blink, tear spreading velocity was computed every 40 milliseconds from particle ...

BACKGROUND: Middle cerebral artery (MCA) detection is useful in monitoring fetal well-being. Knowledge of Doppler flow velocity of the fetal MCA may assist in prenatal diagnosis and management of complicated pregnancies. The aim of this study was to compare the pulsatility index (PI) and resistance index (RI) of the MCA ...

OBJECTIVE: Elevated levels of inflammatory cytokines in the fetus have been linked to neurologic morbidities in preterm neonates. Magnesium sulfate is currently being studied in clinical trials as a potential fetal neuroprotective agent. The purpose of this study was to determine whether intrapartum magnesium sulfate therapy has an effect on ...

OBJECTIVES: To reanalyze randomized controlled trials on the use of umbilical artery Doppler velocimetry in high-risk pregnancies and determine which high-risk pregnancies benefit from the use of Doppler velocimetry. METHODS: Searching Medline, the Cochrane Library and Embase we found 13 randomized controlled trials on the use of Doppler velocimetry in ...

Both the fetal and maternal microvasculature of bovine placentomes was examined by scanning electron microscopy of vascular casts. So far the development of the vascular architecture of the bovine placentome in early gestation has only been studied 2-dimensionally due to technical difficulties arising from the fragility of the early placental ...

This study was conducted to investigate the association between uterine artery Doppler flow patterns and uteroplacental vascular pathology in normal and complicated pregnancies in view of the recently described concept of heterogeneous causes of hypertensive pregnancy complications. Forty-three women whose pregnancies were complicated by pre-eclampsia, the HELLP (Haemolysis, Elevated Liver ...

OBJECTIVE: To examine longitudinal changes in middle cerebral artery blood flow assessed by Doppler in severely growth restricted fetuses. METHODS: Eighteen structurally normal singleton pregnancies complicated by suspected intrauterine growth restriction were monitored by serial measurement of the pulsatility index of the middle cerebral artery over 7 to 72 days. ...

A therapeutic abortion was conducted on a 17-week-old male fetus with a large umbilical cord teratoma associated with an exomphalos. A review of the literature revealed ten other cases of umbilical cord teratoma and shows that these tumors have a very polymorphic presentation. Four fetuses and infants died from various ...

OBJECTIVE: To assess the usefulness of placental and fetal Doppler velocimetry in the surveillance of gestational diabetes mellitus (GDM). STUDY DESIGN: We studied 89 patients with GDM. All fetuses underwent umbilical, fetal descending thoracic aorta and fetal middle cerebral artery pulsatility index (PI) assessment. Doppler results were not used for ...

OBJECTIVE: The aim of these studies was to compare venous perfusion in umbilical cords subjected to a standardized tight encirclement force. Comparisons were made between cords from normal pregnancies and those complicated by gestational diabetes mellitus and intrauterine growth restriction. STUDY DESIGN: The cannulated cord segment was wrapped around a ...

PURPOSE: The purpose of this study was to evaluate the fetal brachial artery resistance index (RI), its changes throughout gestation, and its relationship to the umbilical artery RI. METHODS: One hundred fifty-four sonographic examinations of the brachial and umbilical arteries in 71 fetuses were performed between 12 and 40 weeks' ...

OBJECTIVE: Prospectively evaluate semi-quantitative computer analysis of power Doppler (PD) signals in the placenta, tetal brain, lung, liver, kidney and spleen in high-risk pregnancies in relationship to perinatal outcome and also to compare tissue blood flow in the fetal brain and placenta with Doppler velocimetry. METHODS: PD signals were recorded ...

OBJECTIVE: To test whether late normalisation of abnormal uterine velocimetry is a favourable prognostic factor in high risk pregnancies. STUDY DESIGN: Uterine artery colour Doppler velocimetry was performed at 24, 28-30 and 32-34 weeks in 282 high risk pregnancies treated with low dose aspirin. RESULTS: 88 patients had abnormal waveforms ...

OBJECTIVE: To evaluate the influence of acupuncture on the blood flow in the umbilical artery (UA), fetal aorta and uterine artery and on the fetal heart rate using two different acupuncture points (SP-6 (Sanyinjiao) and LI-4 (Hegu)). METHODS: In group A (n = 50), measurements (Doppler ultrasound and fetal heart ...

PURPOSE: The aim of this study was to investigate the effect of thromboprophylactic therapy on fetal and maternal Doppler flow parameters in pregnant women with severe complications in previous pregnancies and evidence of acquired or congenital thrombophilia in the current pregnancy. METHODS: Sixty-five patients with a history of recurrent abortions, ...

In a cohort of normotensive small-for-gestational-age (SGA) pregnancies, we aimed to determine the prevalence of later preeclampsia and gestational hypertension. We hypothesised that (i) uterine artery Doppler abnormalities would increase in severity from those with normotension to gestational hypertension to preeclampsia and (ii) the severity of uterine artery Doppler abnormalities ...

OBJECTIVE: We report the frequency of associated congenital abnormalities in fetuses with a single umbilical artery as well as the sensitivity, specificity, positive predictive value and negative predictive value of ultrasound for detecting these abnormalities. We also report the pregnancy outcome of fetuses complicated by single umbilical artery, both isolated ...

OBJECTIVE: To study the fetal cardiac isovolumetric contraction time in normal and complicated pregnancies with placental vascular disease using a newly developed digital Doppler cardiography system. DESIGN: A preliminary case-control study. SETTING: Tertiary referral hospital. SAMPLE: One hundred and sixteen normal fetuses (20 to 40 weeks) and 55 complicated pregnancies ...

BACKGROUND: There are few longitudinal data currently available detailing the normal changes in maternal cerebral hemodynamics during human pregnancy. This lack of information limits the study of pregnancy-associated cerebrovascular adjustments and, in particular, preeclampsia, where the brain appears to be especially susceptible to ischemic and encephalopathic injury. Our objective was ...

OBJECTIVES: To assess vascular impedance at three different locations in the middle cerebral artery (MCA) in normal fetuses throughout gestation. MATERIALS AND METHODS: Uncomplicated singleton pregnancies at 15-40 weeks' gestation in which Doppler surveys of both MCAs could be obtained were recruited. The pulsatility index (PI) and resistance index (RI) ...

Fetal echocardiography can be used to detect congenital heart disease prenatally with a high degree of accuracy, and complex heart malformations have also been clearly described in the fetus. However, it is difficult to diagnose correctly or to exclude definitely aortic coarctation by fetal echocardiography. A 23-year-old woman was referred ...

Spontaneous umbilical cord hematoma is very rare. We present a newborn who was discovered to have a spontaneous fetal umbilical cord hematoma. A nonreassuring fetal heart tracing complicated the first and second stages of labor. The only pathological finding was a short umbilical cord, which could have contributed to the ...

AIMS: We wanted to investigate whether experimental dietary manipulations during early pregnancy influence placental growth and subsequently the cardiovascular system as assessed non-invasively by ultrasonography in the sheep fetus. METHODS: 21 ewes bearing singletons of uniform age were randomly assigned for the first half of pregnancy to one of the ...

PURPOSE: Considering the accompanying hemodynamic changes Doppler studies have recently been performed for early diagnosis of intrauterine growth restriction (IUGR) cases with high morbidity and mortality. In the present study, Doppler study of the fetal thoracic aorta was conducted and the sensitivity and specificity of the study was assessed in ...

OBJECTIVE: To assess the activity of the human fetal atrial natriuretic peptide system in hypertensive pregnancies with and without signs of increased fetal systemic venous pressure and in pregnancies complicated by fetal acidemia during labor. METHODS: Umbilical artery plasma N-terminal peptide of proatrial natriuretic peptide concentrations were measured in neonates ...

BACKGROUND: The effect of antenatal betamethasone on fetal parameters includes a transient reduction of FHR variation and of fetal body movements. An effect on maternal-fetal blood flow has also been shown, with non-univocal results. AIMS: To evaluate the effect of antenatal betamethasone in third trimester singleton high-risk pregnancies by Doppler ...

The purpose of this study was to find out if the coiling density is similar in all segments of term singleton umbilical cords. We compared the coiling index (coils/cm) at three different segments of 159 cords. There was no statistical difference between the coiling indices of the placental and middle ...

OBJECTIVE: To characterize the maternal and fetal presentation of abruptio placentae and associated maternal and fetal morbidity and mortality by mode of delivery and fetal status on admission. STUDY DESIGN: Perinatal data (gestational age > 24 weeks) from women with abruptio placentae at a tertiary referral center were analyzed. For ...

The yolk sac is an organ of increasingly recognized importance in the initial mechanisms of pregnancy maintenance and the early growth and welfare of the embryo. The aim of our study was to assess the vascularity of the yolk sac and vitelline duct in 150 patients between the 6th and ...

A crucial event in human development is trophoblast invasion, a process that will enable chorionic and maternal circulations to develop in a synchronized fashion. Early embryo and trophoblast are very sensitive to the conditions in which they grow, and progressive development of placental circulations is essential for normal pregnancy development. ...

Knowledge of fetal hemodynamic physiology has developed enormously during the last two decades due to Doppler ultrasound. Some of this knowledge has been utilized for routine surveillance of high-risk pregnancies. The prediction of fetal hypoxia before the development of life lasting sequel is of major importance, especially in the very ...

We examined the fetal circulatory responses to maternal blood loss in pregnant women during the third trimester. Seven healthy women with placenta previa and singleton pregnancies underwent phlebotomies in an autologous donation program. Four hundred milliliters of blood was collected within 15 min at 34 and 35 weeks of gestation. ...

Based on changes of erythrocyte deformability (ED) found in normal pregnancy the authors decided to study the group of pregnant women with intrauterine fetal hypoxy. We selected 47 pregnant patients between 32 and 37 weeks of pregnancy with intrauterine fetal hypoxy, which was diagnosed by Doppler umbilical cord artery blood ...

OBJECTIVE: To investigate a new method of quantification of the diastolic notch of the flow velocity waveforms of uterine arteries in the prediction of hypertensive disorders of pregnancy. METHODS: Pulsed-wave Doppler was used to obtain flow velocity waveforms (FVWs) from the uterine arteries at 21-22 weeks of gestation from 531 ...

OBJECTIVE: To compare blood perfusion expressed as pulsatility index (PI) and 'notching' of the left and right uterine arteries measured in the same woman in her first and second pregnancies. METHODS: Data from 1102 women's uterine perfusion in their first and second pregnancies were evaluated. Bilateral data, PI and early ...

OBJECTIVE: Our aim was to test the hypothesis that Doppler velocimetry of the peripheral and central circulations in normal fetuses is not affected by moderately high altitude (Denver, Colo-1609 m) compared with sea level (Milan, Italy-40 m). STUDY DESIGN: One hundred nineteen patients with singleton pregnancies underwent Doppler waveform analysis ...

BACKGROUND: Cyclooxygenase-2 inhibitors might have fewer adverse fetal effects than conventional nonsteroidal anti-inflammatory drugs that inhibit both isoforms of the enzyme. Although cyclooxygenase-2 is expressed in fetal kidneys, there are no reports of adverse effects in human pregnancy. CASE: A 27-year-old woman, gravida 2, para 0, with a twin pregnancy ...

1. Using the Fick principle and tracer methodology, the metabolic rates of chronically catheterized fetal foals (n = 24) were measured at different gestational ages during the second half of gestation and in response to maternal fasting for 36 h in late gestation (n = 4, term approximately 335 days). ...

The present work has been designed to validate the calculation of the effective regurgitant orifice (ERO) area with the use of a new formula that takes into account the velocity profile (V(r) vs r) and that is insensitive to errors in the determination of the position of the orifice. Assuming ...

The normal umbilical cord coil index is one coil/5 cm, i.e., 0.2 +/- 0.1 coils completed per cm. We report the frequency and clinical correlations of abnormally coiled cords among 1329 cases referred to our placental pathology services. Twenty-one percent of cords were overcoiled and 13% were undercoiled. Abnormal cord ...

During a span of 3.5 years, a 30-year-old, gravida 9, para 3 woman experienced 3 pregnancies complicated by umbilical cord torsion and constriction. In each case, the complication resulted in acute vascular compromise and intrauterine fetal demise. Gross examination disclosed cord constriction and torsion at the fetal end of the ...

Amniocentesis for amniotic fluid bilirubin levels is the most widely used test to predict the severity of fetal disease in red-cell alloimmunization. Many textbooks and guidelines recommend serial amniocentesis to monitor these pregnancies. However, the reliability of amniotic fluid bilirubin measurements has been questioned. Two strategies have been proposed by ...

OBJECTIVES: To study the tertiary-stem villi vessel lumen and wall thickness of placenta in pregnancy complicated with placental insufficiency and intrauterine growth retardation (IUGR), its correlation with the umbilical artery Doppler flow study, and compare with normal and non-IUGR pregnancies. METHODS: Placentas from 45 deliveries (between 28 and 38 weeks) ...

The adaptation of vascular tone in early pregnancy precedes and probably triggers blood volume and cardiac output increase. Because the endothelium is known to regulate vascular smooth muscle action, the role of nitric oxide (NO) in the setting up of adequate uteroplacental and renal blood flow during normal pregnancy was ...