Cordocentesis in IUGR fetuses.
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Acid-Base Equilibrium↗
Biomedical subjects
G Lingman
Publications and source records attributed to G Lingman.
The female pelvic floor: a dome--not a basin.
BACKGROUND: Classically and based on necropsy observations, the muscles of the pelvic floor (the levator ani and coccygeus muscles) have been described as having the shape of a basin. In a previous study by Hugosson et al. (1991), magnetic resonance imaging revealed the dome shape of the pelvic floor in live subjects when muscular tonus is present. METHODS: The normal anatomy and the dynamic movements of the female pelvis were examined with magnetic resonance imaging including conventional and fast sequences. Six nulliparous and six parous healthy women without signs or symptoms of pelvic relaxation were studied in the supine position at rest, during voluntary pelvic contractions and during bearing down. RESULTS: The levator ani muscle was dome-shaped at rest. During voluntary pelvic contractions the muscle straightened, becoming more horizontal and during bearing down it descended, becoming basin-shaped. The width of the genital hiatus was the same in both groups at rest and it widened during bearing down in all but two 3-para women. The bladder base was lifted upward and forward during voluntary pelvic contractions but during bearing down it descended. The rectum at rest had a posterior angle which decreased during voluntary pelvic contractions and increased during bearing down. CONCLUSIONS: MRI of the female pelvis is valuable in anatomic and dynamic analysis in healthy women and offers new information about the female pelvic floor. The female pelvic floor is shaped like a dome-not like a basin.
Adult↗
Cordocentesis.
During the last decade cordocentesis has become common procedure in perinatal medicine. Although the method represents potential possibilities, it is also afflicted with several limitations. The present review focuses on technique, indications, and complications.
Bradycardia↗
Umbilical artery Doppler flow-velocity waveforms and fetal acid-base balance in Rhesus-isoimmunized pregnancies.
Pulsed Doppler blood-flow velocity waveforms in the umbilical arteries, as well as blood gases, hematocrit, and lactate concentration in umbilical venous blood, were examined in 21 patients undergoing 49 cordocentesis, 34 of which were followed by fetal blood transfusion into the umbilical vein. The aim of the study was to evaluate the correlations, if any, between the Doppler indices from the umbilical artery (pulsatility index, resistance index, systolic/diastolic ratio) and the blood gas values (pO2, pCO2, O2 content, pH) and lactate content in the umbilical vein. The only correlation confirmed in this study was in the subgroup of anemic fetuses undergoing fetal blood transfusion, where correlation existed between A/B and the initial O2 content (r = -0.41, p < 0.02). We conclude that, in Rhesus-isoimmunized pregnancies, in contrast to other pregnancies, a close correlation does not exist between the Doppler indices in the umbilical artery and the fetal blood gas values.
Acid-Base Equilibrium↗
Umbilical artery Doppler flow-velocity waveforms in Rhesus-isoimmunized fetuses before and after fetal blood sampling or transfusion.
Pulsed-Doppler examinations of blood-flow velocities in the umbilical artery were carried out before and after 15 diagnostic cordocenteses and 34 fetal blood transfusions into the umbilical vein. There were decreases in the systolic/diastolic ratio (A/B) (p < 0.01), the pulsatility index (PI) (p < 0.05), and the resistance index (RI) (p < 0.01) after cordocentesis but not after fetal blood transfusion. There were no correlations between the initial hematocrit and the umbilical artery Doppler indices in the sample nor in the fetal blood sampling group. In the fetal blood transfusion group, on the other hand, there was a negative correlation between the initial hematocrit and A/B (r = -0.44; p < 0.01) and the RI (r = -0.35; p < 0.05). The umbilical artery Doppler flow-velocity indices did not predict the fetal hematocrit.
Blood Flow Velocity↗
Oxygenation of the human fetus as a function of hemoglobulin concentration.
We studied the relationships between fetal hemoglobin concentration, acid base status, and lactate concentration in umbilical venous and fetal heart blood in 157 fetuses affected by blood group incompatibility who had been exposed for 214 fetal blood sampling procedures (cordocentesis in 153 and intracardiac puncture in 61 cases). All blood samplings were obtained before fetal blood transfusions were administered. The results indicate that the human fetus can maintain a normal acid-base status until a 50% reduction of the hemoglobin concentration. A further reduction of hemoglobulin is associated with an accumulation of lactate both in umbilical venous and fetal heart blood. The partial oxygen tension and the oxygen saturation in umbilical venous blood remained virtually unchanged with decreasing hemoglobin concentration (r = -0.11, P = 0.21; r = 0.09, P = 0.31, respectively), whereas these parameters decreased significantly (r = 0.33, P = 0.02; r = 34, P = 0.02) in blood obtained from the fetal heart. The partial carbon dioxide tension of umbilical vein blood decreases significantly with a reduced hemoglobin concentration (r = 0.25 P = 0.008). We speculate that these alterations in acid-base status in umbilical vein and fetal heart blood reflect a circulatory transition from a high to a low cardiac output as the hemoglobin concentration decreases.
Acid-Base Equilibrium↗
Hypoxanthine in fetal umbilical venous blood and amniotic fluid from pregnancies complicated by rhesus isoimmunization.
Concentrations of hypoxanthine (HX) was determined in umbilical venous blood and amniotic fluid obtained at 74 instances in 36 rhesus immunized patients before the onset of labor. HX concentrations were related to gestational age, concentrations of hemoglobin and lactate, pH, and partial oxygen pressure in umbilical venous blood. Multiple regression analysis revealed hemoglobin concentration to be the only variable that had any explanatory power to HX in amniotic fluid. No one of the studied variables gave any significant contribution to a regression model to explain HX in umbilical venous blood. We conclude that HX levels in umbilical venous blood and in amniotic fluid from rhesus immunized patients were not associated with fetal blood gases before the onset of labor.
Amniocentesis↗
Erythropoietin concentrations in amniotic fluid and umbilical venous blood from Rh-immunized pregnancies.
We set out to investigate prospectively the levels of erythropoietin in amniotic fluid and umbilical venous blood, and to attempt to relate these to fetal haemoglobin and lactate concentrations and to pCO2 and PO2 in Rh immunised patients studied before the onset of labor. Fetal blood was obtained by cordocentesis, and amniotic fluid by amniocentesis from a consecutive series of 36 Rh immunized patients at the time of fetal blood sampling. There was a close correlation (tau = 0.357, P = 0.0001) between the concentrations of erythropoietin in umbilical venous blood and those in amniotic fluid. Erythropoietin in umbilical venous blood correlated inversely with hemoglobin (tau = 0.453, P = 0.0001), and directly with lactate concentrations (tau = 0.450, P = 0.0005). When all other variables were considered, multiple regression analysis demonstrated hemoglobin concentration to be the only variable to be related to the level of erythropoietin in umbilical venous blood taken before transfusion. When the same analysis was performed on the same variables, adding erythropoietin concentration in amniotic fluid as the dependent variable, only erythropoietin in umbilical venous blood was found to be related to the level of erythropoietin in amniotic fluid. We conclude that the erythropoietin concentration in umbilical venous blood from Rh-immunized patients before the onset of labor, is related to fetal anemia. We also conclude that erythropoietin concentration in amniotic fluid is related to that in fetal blood, thereby indicating that the fetus is an important source of amniotic fluid erythropoietin in non laboring patients.
Amniotic Fluid↗
Mucopolysaccharidosis VII as cause of fetal hydrops in early pregnancy.
We report on fetal hydrops presenting at 18 weeks of gestation and diagnosed as beta-glucuronidase deficiency. The parents were first cousins and there were 2 previous similar fetal deaths. beta-Glucuronidase was absent in cultured fetal fibroblasts and lymphoblasts but was normal in the tested relatives. The activities of other lysosomal enzymes were normal.
Adult↗
Lack of relation between fetal blood gases and fetal blood flow velocity waveform indices found in rhesus isoimmunised pregnancies.
OBJECTIVE: To investigate the relation between umbilical vein blood gas components and the vascular resistance in four fetal arteries in Rh-immunised pregnancies. DESIGN: A prospective observational study over a 4-month period. SETTING: King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. SUBJECTS: Fifteen Rh-isoimmunised pregnant women. INTERVENTIONS: Pulsed Doppler examinations of the umbilical artery, fetal internal carotid artery, thoracic aorta and abdominal aorta before transabdominal fetal blood sampling from the umbilical vein on 38 occasions. MAIN OUTCOME MEASURES: Doppler flow velocity pulsatility index (PI), systolic/diastolic ratio (A/B) and resistance index (RI) in the four fetal arteries investigated were related to the umbilical vein blood gases and acid-base status (PO2, PCO2, O2-content, CO2-content, HCO3, base excess and lactate concentration). RESULTS: There were no correlations between the Doppler indices in any of the vessels studied and the blood gases components in the umbilical vein. The ratios between the corresponding Doppler indices in the different vessels were also independent of the blood gases and acid-base status and there were no significant differences in the Doppler indices in the same vessel between fetuses with blood gas values over the 75th centile and those with values below the 25th centile. CONCLUSION: This study does not support a reduction in peripheral vascular resistance in the fetal cerebrum in relation to fetal hypoxia in Rh-immunized pregnancies.
Blood Flow Velocity↗
Intracardiac rhabdomyomas in neonates: report of three cases.
Three cases of intracardiac rhabdomyomas in neonates are presented. All were diagnosed by ultrasound, one prenatally and two directly after birth. Two of the patients were operated on during the neonatal period. The operations were carried out on the ultrasound findings alone. One patient was considered inoperable and died at three weeks of age. The two surviving patients have no cardiac symptoms and involution of the tumors has taken place. Two of the three patients have shown signs of tuberous sclerosis.
Female↗
Placental morphology in relation to umbilical artery blood velocity waveforms.
The association between umbilical artery flow velocity waveforms, placental morphology and arterial vascular pattern was investigated in 30 pregnant women at risk for intra-uterine growth retardation. The blood velocity waveform was assessed in the umbilical arteries with pulsed Doppler ultrasound. Placentas from fetuses with an end-diastolic zero flow were small and thick with an extrachorial configuration, marginal cord insertion, magistral or mixed allantochorial vessel pattern and few cotyledons. The incidence and the extension of gross lesions were slightly increased in these placentas compared to placentas from fetuses with a normal S/D ratio (peak systolic velocity/minimum diastolic velocity). Placentas from fetuses with an increased S/D ratio (greater than +2SD) were large and thin with a high maximum diameter/maximum thickness ratio. Heavily smoking mothers were overrepresented in the group, with an increased S/D ratio and corresponding SGA infants. End-diastolic zero flow in the umbilical artery was strongly correlated with placental developmental abnormalities.
Angiography↗
Rhesus immunization: new perspectives in maternal-fetal medicine.
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Blood Transfusion, Intrauterine↗
Diameters of the common carotid artery and aorta change in different directions during acute asphyxia in the fetal lamb.
The aim of this experimental ultrasound study on six fetal lambs was to evaluate how blood flow variables and vessel diameters of the descending aorta and the common carotid artery change during fetal asphyxia in the acute preparation. When acute asphyxia was induced by obstructing the maternal aortic blood flow all fetuses reacted with significant decrease in the aortic diameter and blood flow. In the common carotid artery vessel diameter and the blood flow increased significantly. The results support the theory of a brain sparing effect during fetal distress with significant changes of blood vessel diameters occurring in opposite directions in the aorta and the common carotid artery, thereby contributing to the centralisation of circulation.
Animals↗
Recording of blood flow velocity waveforms in the uteroplacental and umbilical circulation: reproducibility study and comparison of pulsed and continuous wave Doppler ultrasonography.
Reproducibility of the blood flow velocity waveforms (FVW) recorded from the umbilical artery and the arcuate arteries on the right and left side of the placenta was examined in 8 women with normal pregnancies and anterior placentas. The FVW were recorded using a 2-MHz pulsed Doppler ultrasound system in combination with a real-time linear-array scanner. The FVW were characterized by the pulsatility index (PI) and systolic/diastolic (S/D) ratio. For the PI, the mean coefficients of variation between six operator pairs in the umbilical artery and the left and right arcuate arteries were 8.4%, 26%, and 21.5%, respectively. These findings suggest that, in clinical practice, the umbilical artery FVW is reproducible, but the usefulness of arcuate artery FVW is limited by the wide variation of Doppler signals. Paired recordings of FVW were obtained from the umbilical, arcuate, and uterine arteries using pulsed wave and continuous wave Doppler ultrasonography in a randomized order in another 21 pregnant women with anterior placentas. There was no difference between the two Doppler modes for any of the measured waveform indices.
Arteries↗
Anal sphincter function after delivery: a prospective study in women with sphincter rupture and controls.
Twenty-one consecutive women with anal sphincter muscle rupture during delivery (0.79%) and 15 controls were examined. The anal sphincter was immediately repaired in the study group and the function determined with anal profilometry at 3 days and 3 months after delivery, and in ten of the patients after 12 months. Anal sphincter strength was reduced soon after delivery in the controls but regained normal strength within 3 months. In the anal sphincter rupture group, an improvement was found over the first 3 months after delivery, but afterwards no further change occurred. The anal sphincter strength was significantly reduced compared to the control group, both soon after delivery and after 3 months. Their voluntary anal pressure increased from 1.7 kPa immediately after delivery to 3.2 kPa at 3 months in the study group and the corresponding values in the control group were 4.0 and 6.5 kPa, respectively. For the closing pressure, that is the resting pressure minus the rectal pressure, the values in the study group were 4.2 and 6.7 kPa, and in the control group 7.2 and 9.4 kPa, respectively. In the women with anal sphincter rupture, however, a significantly increased frequency of gas incontinence was found.
Adult↗
Cerebral blood flow during labor in the human fetus.
A method is described for recording blood flow velocity waveforms from fetal cerebral vessels during labor, using a 2 MHz pulsed Doppler ultrasound technique. Fifteen healthy women with uncomplicated pregnancies and labor without signs of fetal distress participated in the study. With membranes ruptured and cervix orifice open 4-9 cm, the Doppler transducer was placed transvaginally on the fetal skull and the Doppler shift signals from the middle cerebral artery were located. The maximum velocity waveforms were recorded before, during and after uterine contractions and analysed off-line for pulsatility index (PI). No differences in the PI were found with regard to the uterine contractions. The results suggest an unchanged peripheral resistance in the fetal cerebral vascular bed during the first stage of normal labor.
Blood Flow Velocity↗