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PubMed2003

Development of catheter-type optical oxygen sensor and applications to bioinstrumentation.

A catheter-type optical oxygen sensor based on phosphorescence lifetime was developed for medical and animal experimental use. Since the sensor probe should have biocompatibility and high oxygen permeability in vivo, we focused attention on acceptable polymer materials for contact lenses as the substrates of probes. Pd-porphyrin was doped in silicone-based polymer, and was fixed at the edge of an optical fiber inserted in a catheter tube. The shape of the probe was 600 microm in diameter and 100 microm in thickness, and the probe had high oxygen permeability of Dk value 455. In accuracy evaluation, there found an excellent correlation between the pO2 values measured through phosphorescence lifetime using the oxygen sensors and those measured as the calibrating data using oxygen electrodes. The response time required to achieve 90% from reversible default value to be from 150 to 0 mmHg, and from 0 to 150 mmHg was 15.43 and 7.52 s, respectively. In addition, other properties such as temperature and pH dependency, response, and durability of our optical oxygen sensor were investigated. In animal experiments, the catheter-type oxygen sensor was inserted via the femoral artery of a rat, and arterial oxygen pressure was monitored under asphyxiation. The sensor was valid in the range of oxygen concentration sufficient for biometry, and expected to be integrated with an indwelling needle.

Animals↗

PubMed1998

Ultrasound in the diagnosis of twin-to-twin transfusion syndrome--a preliminary report.

OBJECTIVE: The aim of this study was to show the diagnostic possibilities of ultrasound in twin-to-twin transfusion syndrome (TTTS), to demonstrate its usefulness in cases of hemoglobin difference < 5 g/dL in neonates as well as in cases complicated by intrauterine death of one or both twins. STUDY DESIGN: The study included 4 pairs of twins. In two cases 3 fetuses died in utero. In the other two the hemoglobin difference in newborn infants was < 5 g/dL. The ultrasound examination, evaluating the fetal anatomy and biometry, amniotic fluid volume, placentation, was performed. The special attention was paid to polyhydramnios/oligohydramnios, discordant fetal growth (fetal weight, abdominal circumference), the presence of fetal hydrops, ascites, pericardial effusion. Doppler blood flow velocimetry has been done in umbilical vessels, middle cerebral artery. The data was compared with normal reference values for singleton pregnancies. The waveforms from both uterine arteries were also evaluated to exclude placental insufficiency. Additionally the blood flow through the AV valves was measured to exclude or confirm its regurgitation. Postnatally the hemoglobin difference was evaluated if available and compared with sonographic findings. RESULTS: In all cases inter-twin difference in abdominal circumference was greater than 18 mm and inter-twin weight difference of more than 15%. We observed polyhydramnios/oligohydramnios in all twin pregnancies. It has been found decreased PI in middle cerebral artery in larger fetus (recipient) in all our cases (comparing to single pregnancy). PI values for this vessel in smaller fetuses were within normal range (for single pregnancy). PI values in umbilical arteries of recipients were abnormal (increased PI or absent end-diastolic flow). COMMENTS: The sonographic criteria seem to be very useful in diagnosis of twin-to-twin transfusion syndrome, especially in cases where the measurement of hemoglobin level is impossible. Doppler blood flow velocimetry in fetal vessels helps to explain the changes in fetal hemodynamics in TTTS.

Blood Flow Velocity↗

PubMed1991

The definition, diagnosis, and management of growth-discordant twins: an international census survey.

In order to establish a protocol considering the definition, diagnosis, and management of growth-discordant twin gestations, a questionnaire was sent to 96 authors of twin-related obstetric articles. The views of the 61 responders comprise this international census survey. The data suggest that a clear cut-off value for discordancy is still needed; however, the data indirectly supported a two-grade definition, namely, mild (greater than 15% and less than 25% birth-weight disparity) and severe (greater than 25%) growth discordants. Expectant management was advocated by the majority of participants with out-patient follow-up for mild discordants, while severe discordants may preferably be hospitalized. Follow-up should be done by non-stress testing (daily - 2/wk), biophysical profile (1-2/wk), Doppler velocimetry (1/wk - bi-weekly) and sonographic biometry (bi-weekly). The opinions considering termination of pregnancy because of intertwin growth discordancy were divided; however, discordancy per se, was not considered an indication for cesarean delivery. An adapted management flowchart that summarizes the survey's data is presented and may be used as a standard for future investigations.

Birth Weight↗

PubMedDate not supplied

'Minimal-change hypertensive retinopathy' and 'arterial pre-hypertension', illustrated via ambulatory blood-pressure monitoring in putatively normotensive subjects.

PURPOSE: To investigate the 24 h blood-pressure (BP) pattern in subjects who were found to show some incipient signs of hypertensive retinopathy but had been diagnosed as normotensives by means of casual sphygmomanometry. METHODS: Non-invasive ambulatory BP monitoring was performed in 25 caucasian subjects (16 M, 9 F; mean age 46 +/- 16 years) showing this type of retinal problem. A comparable number of controlled normotensive Caucasian subjects (15 M, 10 F; mean age: 48 +/- 15 years) without funduscopic signs of hypertensive retinopathy were investigated as a reference group. A series of BP tests over time was analysed by means of conventional biometry and chronobiological methods. RESULTS: The biometric estimates suggest that the investigated subjects with incipient hypertensive retinopathy, although characterized by BP values below 140/90 mmHg, show a significantly higher daily systolic BP. The increase, however, is within WHO reference limits and is not associated with the abolition of the circadian BP rhythm. CONCLUSIONS: The results suggest that the initial signs of hypertensive retinopathy may appear before BP elevation above WHO reference limits occurs. Because of this, it can be assumed that there is such a condition as 'minimal-change hypertensive retinopathy' associated with a haemodynamic picture of 'arterial pre-hypertension'.

Blood Pressure↗

PubMed2003

Dietary effect of different high-fat diet on rat liver stereology.

BACKGROUND/AIMS: Dietary habits are considered to be responsible for a fatty liver. The aims of this work are to study the effects of different lipid sources on rat hepatic structure. METHODS: Twenty 21-day-old to 18-month-old male rats were fed one of the following diets: soybean oil, canola oil, lard and egg yolk (LE), or canola oil+lard and egg yolk (CA+LE). The blood serum triglyceride samples were analyzed. The following hepatic biometry and the stereology parameters were determined: densities of volume (V(v)) and surface (S(v)), absolute volume (V) and surface (S) of the hepatocytes (h), fat globules (g), and hepatic sinusoids (s), and numerical density of the hepatocytes (N(v)[h]). RESULTS: The largest values of V(v)[h], S(v)[h], V[h], and S[h] were found in the LE group. However, the largest values of V(v)[g], S(v)[g], and S[g] were found in the CA+LE group, and the smallest values of those parameters were found in the LE group. On the other hand, V[g] was larger in the CA+LE group. V(v)[s] and V[s] were larger in the LE group and smaller in the CA+ LE group. CONCLUSION: Long-term administration of canola oil or soybean oil resulted in similar effects on hepatocytes, hepatic sinusoids, and fat globules. Long-term administration of lard and egg yolk attenuates hepatic fat accumulation and increases hepatic sinusoids. The administration of the canola oil and lard and egg yolk mixture increases hepatic fat accumulation, reducing the hepatic sinusoids.

Animals↗

PubMed1999

The comparison of cyclopentolate and atropine in patients with refractive accommodative esotropia by means of retinoscopy, autorefractometry and biometric lens thickness.

PURPOSE: In this study, we aimed to compare the cycloplegic effect of cyclopentolate HCI 1% and atropine sulphate 1% in patients with refractive accommodative esotropia by means of retinoscopy, autorefractometer and the measurement of lens thickness by biometry. METHODS: Thirty-two patients with refractive accommodative esotropia aged from 5 to 10 (mean 6.8+/-1.4), had a deviation under 10 prism diopters, and underwent retinoscopic, autorefractometric and biometric study in dry and wet conditions. RESULTS: The retinoscopic, autorefractometric and biometric findings of the right eye were 5.10+/-1.21 diopter (D), 5.03+/-1.20 D, 3.43+/-0.16 mm with cyclopentolate, and 5.2+/-1.2 D, 5.2+/-1.2 D, 3.4+/-0.1 mm with atropine. In the left eye, the measurements were 5.2+/-1.4 D, 5.1+/-1.4 D, 3.5+/-0.2 mm with cyclopentolate, and 5.3+/-1.2 D, 5.20+/-1.3 D, 3.4+/-0.2 mm with atropine, respectively. When these obtained data were compared by the Student's t test no statistical significance was found (p > 0.05). CONCLUSIONS: We suggest that the cyclopentolate cycloplegia applied to the patients with refractive accommodative esotropia is sufficient to produce good cycloplegia, with an effect similar to atropine.

Accommodation, Ocular↗

PubMed1988

Intraocular lens power calculation.

Accurate intraocular lens power calculation is an important adjunct to the technique of extracapsular cataract extraction. An increasing number of ophthalmologists now perform preoperative biometry routinely. We studied a group of fifty patients and analysed the accuracy of intraocular lens power calculation using the SRK formula.

Adult↗

PubMed1993

Refractive results after corneal triple procedures (PK+ECCE+IOL)

We have analysed the refractive results of corneal triple procedures (penetrating keratoplasty with extracapsular cataract extraction and posterior chamber intraocular lens implantation) in 52 eyes of 47 patients with a mean follow-up of 39 months. The patients were predominantly old and female and most received unilateral surgery. The contralateral acuity was 6/24 or worse in more than 50% of cases at the time of surgery. Many of these patients were significantly ametropic pre-operatively. Biometry does not seem to have improved the refractive results in those patients in whom it was attempted. The majority of patients were hypermetropic when their refraction stabilised, with resulting poor uncorrected visual performance. Possible improvements are discussed.

Aged↗

PubMed1997

The effect of anaesthesia on the intraocular volume of the C3F8 gas bubble.

Long-acting intraocular gas bubbles are frequently used during vitrectomy to tamponade retinal breaks. The aim of this study was to determine the effect of nitrous oxide anaesthesia on the size and effectiveness of the post-vitrectomy gas bubble. Twenty vitrectomy procedures with injection of 12% perfluoropropane (C3F8) gas were performed. For 10 of the cases routine anaesthesia with nitrous oxide was used and for 10 cases non-nitrous anaesthesia with propofol was used. The volume of the intraocular gas bubble was estimated 24 hours post-operatively using A-scan biometry. At 24 hours the gas bubble occupied a mean of 65.1% of the eye in anaesthesia with nitrous oxide and a mean of 66.1% in anaesthesia with intravenous propofol. The wide range of values of gas-fill recorded at 24 hours makes comparison of the two groups inappropriate. Several factors may account for this spread of values, but in our opinion it is the uncontrolled leakage from the sclerostomies which is the most likely. This study suggests that anaesthesia using nitrous oxide does not adversely affect the size of the C3F8 gas bubble at 24 hours post-vitrectomy when compared with anaesthesia without nitrous oxide.

Adult↗

PubMed1999

Changes in anterior chamber depth and axial length measurements after radial keratotomy.

PURPOSE: To evaluate the changes that occur in anterior chamber depth and globe axial length after radial keratotomy (RK) surgery in cases with different degrees of myopia. METHODS: One hundred and twelve eyes that underwent RK were studied. The eyes were divided into two groups: 70 eyes with a correction of myopia of 4.00 D and under after RK (group 1) and 42 eyes with a correction of myopia of more than 4.00 D (group 2). Routine examinations were done in all cases. Ultrasonic biometry and central anterior chamber depth and axial length were measured pre-operatively and on the third day, second week, third month and sixth month post-operatively. RESULTS: Pre-operatively the average globe axial length was longer in group 2 than group 1. When all post-operative measurements were compared with pre-operative measurements in group 1, there was a decrease in anterior chamber depth and globe axial length, but no significant difference was found except on the third day (t = 3.15, p = 0.003). In group 2 there was an insignificant decrease in axial length but the decrease in anterior chamber depth was significant at all measurement times except for the sixth month. CONCLUSIONS: Refractive changes related to biometric changes after RK are not important compared with the total refractive corrections of RK. These changes should be considered, however, when planning RK procedures.

Adult↗

PubMed2005

Risk management strategies following analysis of cataract negligence claims.

INTRODUCTION: Clinical governance and risk management is very important in today's clinical practice. Cataract surgery is one of the most common procedures performed in the NHS, with around 200,000 operations per year. In order to help minimise the frequency of negligence claims, we performed a collaborative study to analyse claims relating to cataract surgery, dealt with by the defence organisations of England, Scotland, Wales, and Northern Ireland. MATERIALS AND METHODS: All claims dealt with by the Medical Defence Union, the Medical Protection Society, and the Medical and Dental Defence Union of Scotland from January 1990 to December 1999, were analysed by three ophthalmologists with at least 5 years' speciality experience. Recurrent themes were identified and claims were grouped by major causative factor. The findings were discussed by a panel compromising the authors in conjunction with the defence unions and risk management strategies were designed. RESULTS: There were 96 claims within the 10- year period analysed. Of these, the largest group (52) pertained to claims that related to accepted complications of cataract surgery. The remainder comprised two groups: 'Medical Errors' (anaesthetic, surgeon, and biometry) and 'Other Claims' comprising subjective complaints, pain and poor visual outcome. A total of 16 claims had been settled by May 2002, 45 are ongoing and 35 have closed without settlement. CONCLUSIONS: The majority of claims pertained to well-recognised complications of cataract surgery. If these risks are adequately explained to the patient before surgery and if the care provided reaches a standard acceptable to a responsible body of professional opinion, all such claims should be defensible. Good visual outcome does not protect against litigation.

Cataract Extraction↗

PubMed2006

Peripheral and posterior pole retinal lesions in association with high myopia: a cross-sectional community-based study in Hong Kong.

PURPOSE: To evaluate the prevalence and factors associated with posterior pole and peripheral retinal lesions in Chinese subjects with high myopia. METHODS: Three hundred and thirty-seven asymptomatic adults with high myopia of refractive error <or=-6 D were examined in a cross-sectional community-based study. All subjects underwent cycloplegic refraction, ultrasound biometry and dilated fundal examination. Statistical analysis was performed to assess factors associated with the presence of posterior pole and peripheral retinal lesions. RESULTS: The mean age of the 337 subjects was 36.0 years and the mean spherical equivalent refractive error was -10.2 D. Thirty-eight eyes (11.3%, 95% CI=8.1-15.2%) were found to have one or more posterior pole lesions and subjects with posterior pole lesion had significantly older age, longer axial length and higher degree of myopia (all P<0.001) compared with subjects without posterior pole lesion. After controlling for axial length, both the severity of refractive error and older age were significantly associated with the presence of posterior pole lesion (both P<0.001). For peripheral retinal lesions, 189 eyes (56.1%, 95% CI=50.6-61.5%) were found to have one or more peripheral retinal lesions. The presence of peripheral retinal lesion was associated with younger age and higher degree of refractive error (P=0.046 and 0.002, respectively). CONCLUSION: Posterior pole and peripheral retinal degenerative lesions were found in a considerable proportion of subjects with high myopia. As some of these retinal lesions might predispose to visual impairment, highly myopic individuals should be educated on the symptoms of various eye conditions and seek care immediately if symptoms arise.

Adolescent↗

PubMed2002

A new mathematical formula for predicting long bone length in early pregnancy.

OBJECTIVE: To propose new mathematical formulae to estimate fetal long bone biometry in early pregnancy and to establish their efficacy in comparison to previously constructed mathematical formulae. METHODS: A study population of 1960 singleton euploid fetuses was referred for transvaginal ultrasound examinations between 71 and 112 days of gestation prior to genetic amniocentesis. To determine the relationship between the biparietal diameter and long bone length, a sample group of 400 randomly chosen normal fetuses was evaluated. Regression equations were derived, then tested in the remaining 1560 control fetuses and compared with previously reported mathematical formulae by other authors. Mean absolute error, mean absolute percentage error and mean systematic error with their standard deviations were calculated. RESULTS: The relationships between femur or humerus length vs. biparietal diameter (BPD) and gestational age (GA) were, respectively: expected femur length = -16.92108 + 0.4569402 x BPD + 0.171617 x GA (P < 0.001) and expected humerus length = -16.28531 + 0.4283019 x BPD + 0.1696017 x GA (P < 0.001). The confidence intervals of the predicted values for different values of biparietal diameter and gestational age and confidence intervals for the regression coefficients, such as the distribution of the residuals, are given. All previous formulae obtained by transabdominal ultrasound demonstrated an overestimation of expected long bones measurements; this was reduced using different formulae obtained in early pregnancy. Using our mathematical formulae, the mean absolute percentage error and the mean systematic error in estimating femur and humerus length were very low (11.15% and -2.02%; 10.59% and -1.74%, respectively). CONCLUSIONS: The new ultrasonographic morphometric models derived from transvaginal measurements in early pregnancy show a good reliability in estimating fetal long bone length.

Female↗

PubMed2002

Temporal sequence of abnormal Doppler changes in the peripheral and central circulatory systems of the severely growth-restricted fetus.

OBJECTIVE: To identify the temporal sequence of abnormal Doppler changes in the fetal circulation in a subset of early and severely growth-restricted fetuses. METHODS: This was a prospective observational study in a tertiary care/teaching hospital. Twenty-six women who were diagnosed with growth-restricted fetuses by local standards before 32 weeks' gestation and who had abnormal uterine and umbilical artery Doppler velocimetry were enrolled onto the study. To compare Doppler changes as a function of time, pulsed-wave Doppler ultrasound was performed on five vessels in the fetal peripheral and central circulations. Doppler examinations were performed twice-weekly and on the day of delivery if the fetal heart rate tracing became abnormal. Doppler indices were scored as abnormal when their values were outside the local reference limits on two or more consecutive measurements. Biometry for assessment of fetal growth was performed every 2 weeks. Computerized fetal heart rates were obtained daily. Delivery was based on a non-reactive fetal heart rate tracing and not on Doppler information. Patients with a severely growth-restricted fetus who were delivered for maternal indications such as pre-eclampsia were excluded. Perinatal outcome endpoints included: intrauterine death, gestational age at delivery, newborn weight, central nervous system damage of grade 2 or greater, intraventricular hemorrhage and neonatal mortality. RESULTS: Mean gestational age and newborn weight at delivery were 29 (standard deviation (SD), 2) weeks and 818 (SD, 150) g, respectively. The sequence of Doppler velocimetric changes was described by onset time cumulative curves that showed two time-related events. First, for each vessel there was a progressive increase in the percent of fetuses developing a Doppler abnormality. Second, severely growth-restricted fetuses followed a progressive sequence of acquiring Doppler abnormalities which were categorized into 'early' and 'late' Doppler changes. Early changes occurred in peripheral vessels (umbilical and middle cerebral arteries; 50% of patients affected 15-16 days prior to delivery). Late changes included umbilical artery reverse flow, and abnormal changes in the ductus venosus, aortic and pulmonary outflow tracts (50% of patients affected 4-5 days prior to delivery). The time interval between the occurrence of early and late changes was significantly different (P < 0.0001) and late changes were significantly associated with perinatal death (P < 0.01). CONCLUSIONS: Doppler velocimetry abnormalities develop in different vessels of the severely growth-restricted fetus in a sequential fashion. Late changes in vascular adaptation by the severely growth-restricted fetus are the best predictor of perinatal death.

Blood Circulation↗

PubMed1994

Ductus venosus blood velocity and the umbilical circulation in the seriously growth-retarded fetus.

Based on the assumption that the ductus venosus is regulator of oxygenated blood in the fetus, the present study investigated the blood flow velocity of the ductus venosus in relation to the umbilical circulation in the that seriously growth-retarded fetus. The study group of 38 fetuses (gestational week 17-39) had no chromosomal aberrations or structural malformations and had an ultrasonographic biometry of < 2.5th centile and birth weight of <or= 2.5th centile. Of the 38 fetuses seven died in utero and four died postnatally. The ultrasonographic examination included pulsed Doppler measurement of the umbilical artery pulsatility index (PI), the umbilical vein dimension and blood flow velocity, and the peak and maximum blood flow velocities of the ductus venosus. The majority of fetuses had a raised PI in the umbilical artery (26/38) and reduced blood flow in the umbilical vein (25/33). Despite such changes in the umbilical circulation, a normal peak velocity in the ductus venosus was maintained in all fetuses. During the atrial contraction, however, 13 fetuses had reduced or reversed blood velocity in the ductus venosus. Reduced ductus venosus velocity during atrial contraction seemed to be a serious finding linked to raised PI and absent or reversed end-diastolic flow in the umbilical artery, and umbilical vein pulsation. The results support the assumption that the blood flow of the ductus venosus is a preferential bloodstream in the human fetus that is maintained within normal ranges as long as possible during placental hemodynamic compromise.

Journal Article↗

PubMed1995

Changes observed in Doppler studies of the fetal circulation in pregnancies complicated by pre-eclampsia or the delivery of a small-for-gestational-age baby. I. Cross-sectional analysis.

The aim of this study was to compare changes in Doppler ultrasound studies of the fetal circulation in normal pregnancies with a group of pregnancies complicated by proteinuric pregnancy-induced hypertension (PPIH), delivery of a small-for-gestational-age (SGA) baby, or both. A total of 167 uncomplicated pregnancies with a term delivery of an appropriately grown baby (AGA) were used to define the normal range. Altogether, 123 high-risk pregnancies with a known outcome constituted the study group. A color duplex ultrasound machine was used to perform biometry and fetal Doppler studies. Measurements obtained from the fetal circulation included the umbilical artery (UA) pulsatility index (PI), the middle cerebral artery (MCA) PI and time-averaged velocity (TAV), the thoracic aorta (AO) PI and TAV. In addition, the ratio between the MCA PI and UA PI, the MCA PI and the AO PI, and the product of the MCA PI and AO TAV were used in the analysis. A total of 105 pregnancies had a complicated outcome. They were divided into three categories: PPIH only (pregnancies complicated by PPIH with the delivery of an AGA fetus, n = 17), SGA only (delivery of an SGA baby, with no evidence of PPIH, n = 55), and PPIH + SGA (pregnancies complicated by pre-eclampsia and delivery of an SGA baby, n = 37). The PPIH + SGA group represented true clinical intrauterine growth retardation. Cross-sectional reference ranges were created using the observations from the normal group. z-scores (standard deviation from the mean of the normal range) of the last observations made before delivery were calculated for each of the vessel velocimetry measurements and ratios. The statistical significance of z-score values was calculated using analysis of variance. The MCA and UA PI values showed the greatest deviation for any single-vessel parameter. The ratios of fetal Doppler indices (MCA/UA PI ratio, MCA/AO PI ratio and the MCA PI/AO TAV index) demonstrated greater deviation from normal than any individual vessel. The UA PI z-score for PPIH+SGA delivering < 34 weeks gestation (2.92) was significantly greater than the z-score for PPIH+SGA delivering > or = 34 weeks (1.20, p < 0.05). Fetal Doppler indices, in particular ratios that include measurements obtained from the cerebral circulation, help in the recognition of the small fetus that is growth-retarded. At term, evidence of fetal hemodynamic redistribution may exist in the presence of a normal umbilical artery PI. Fetal Doppler indices provide information that is not readily obtained from more conventional tests of fetal well-being.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1995

Measuring the thickness--is that all we have to do for sonographic assessment of endometrium in postmenopausal women?

For sonographic assessment of the endometrium in postmenopausal women, measurement of the maximum thickness is used in many cases as the sole criterion. The cut-off values stated in the literature, however, vary considerably. This prospective study examined 200 female patients in order to ascertain the value of echomorphology in addition to endometrial biometry. Up to an overall endometrial thickness of 3 mm, we observed only histologies without any pathological findings, whereas from an endometrial thickness of 10 mm upwards, only polyps, hyperplasias and carcinomas were found. In more than a third of our patients, the endometrial thickness was between 3 and 10 mm where the structure of the endometrium could reflect the possible histological finding: homogeneity, low echo and a sonographically depictable central echo between symmetrical endometrial leaves were an indication for absence of pathological findings, whereas heterogeneity and high echogenicity were pointers for pathological changes. In contrast to the sole measurement of endometrial thickness in the postmenopause, the combined metric and morphological parameters improve not only the predictability of pathological findings but, above all, the selectivity of the vaginosonographic assessment of the endometrium in postmenopausal women.

Aged↗

PubMed1997

Demonstration of fetal coronary blood flow by Doppler ultrasound in relation to arterial and venous flow velocity waveforms and perinatal outcome--the 'heart-sparing effect'.

This longitudinal observational study evaluates the stage at which coronary flow can be visualized by color-coded and pulsed wave Doppler sonography in fetuses with normal cardiac anatomy. Fetal biometry, echocardiography and Doppler examination of the umbilical and middle cerebral arteries, ductus venosus, inferior vena cava and umbilical vein were performed in 109 cases. Fetuses were divided into five groups based on the Doppler examination of the umbilical artery, birth weight and the ability to visualize coronary blood flow. Coronary blood flow was identified in six of 55 fetuses with normal growth who had normal Doppler studies and perinatal outcome. In these, visualization of coronary blood flow was possible after 31 weeks' gestation at a median gestational age of 37 weeks. Coronary blood flow was also visualized in ten of 54 fetuses with severe intrauterine growth retardation and highly pathological flow velocity waveforms in all vessels soon after a significant increase of venous indices in the inferior vena cava and ductus venosus. In these cases, coronary blood flow was identified at a significantly earlier gestational age (median 27 weeks). These fetuses had a poor perinatal outcome (average birth weight less than 3rd centile, mortality rate 50%, significantly lower umbilical artery blood pH and Apgar scores after 1 and 5 min). Intrauterine fetal death occurred in five fetuses after a median of 3.5 days following visualization of coronary blood flow. Median coronary peak blood flow velocities in the right coronary artery were higher in intrauterine growth-retarded than appropriate-for-gestational-age fetuses.

Blood Flow Velocity↗