Biomedical subjects

Robert Gagnon

Publications and source records attributed to Robert Gagnon.

At least 19 recordsLinked to original sources

PubMed2006

Sources of amniotic fluid erythropoietin during normoxia and hypoxia in fetal sheep.

OBJECTIVE: Erythropoietin is present in human amniotic fluid and has been suggested as a marker of fetal hypoxia. The objectives of the present study were to determine whether erythropoietin is present in ovine amniotic fluid, fetal urine, and/or lung liquid and whether concentrations in these compartments change in parallel with endogenous fetal plasma erythropoietin concentration when the latter is increased experimentally. STUDY DESIGN: In late gestation chronically catheterized fetal sheep, samples of amniotic fluid and plasma, urine and plasma, lung liquid, amniotic fluid, and plasma were collected before and up to 7 days after induction of 4 types of fetal hypoxia: (1) acute anemic hypoxia that was induced by a single fetal hemorrhage, (2) progressive anemic hypoxia that was induced by daily exchange transfusion, (3) acute hypoxic hypoxia that was induced by the reduction of maternal inspired oxygen content, or (4) chronic placental insufficiency that was induced by daily umbilicoplacental embolization for 4 days. Erythropoietin concentrations were determined by radioimmunoassay. Statistical testing included analysis of variance and least squares regression. RESULTS: Under basal, nonhypoxic conditions, amniotic fluid erythropoietin concentration averaged 33.2% +/- 1.6% (SE) of fetal plasma erythropoietin concentration, and basal fetal urine and lung liquid erythropoietin concentrations ranged from low (<10% of plasma concentration) to nondetectable. Unlike the strong correlation in humans, basal amniotic fluid and plasma erythropoietin concentrations were correlated only weakly (r = 0.259; r2 = 6.7%; P = .0027; n = 132). Amniotic fluid erythropoietin concentration approximately doubled after 12 hours of severe hypoxic hypoxia or after 24 hours of embolization-induced severe hypoxia but was unchanged after 12 hours of mild-moderate hypoxic hypoxia or 24 hours of anemic hypoxia. Concomitant fetal plasma erythropoietin concentrations increased to 28.1 +/- 5.3, 12.5 +/- 2.7, 10.8 +/- 4.6, and 10.0 +/- 1.3 times basal values, respectively. During progressive fetal anemia, urinary erythropoietin concentration increased almost 10-fold (P = .0023) but remained a small fraction (3.7% +/- 0.4%) of plasma concentration; at 12 hours of hypoxic hypoxia, lung liquid erythropoietin concentration did not vary with the severity of the hypoxia and remained low relative to plasma concentration (4.2% +/- 2.1%). CONCLUSION: Erythropoietin is present in ovine amniotic fluid, urine, and lung liquid. With only 3 potential sources, the fetal membranes appear to be the primary source of amniotic fluid erythropoietin in the nonhypoxic ovine fetus because basal urine and lung liquid erythropoietin concentrations are much lower than amniotic fluid concentrations. Although unchanged during mild-to-moderate fetal hypoxia, amniotic fluid erythropoietin concentration increases modestly during severe fetal hypoxia. In sheep, fetal urinary erythropoietin may contribute to this rise in amniotic fluid erythropoietin concentration during severe hypoxia, because fetal urinary and plasma concentrations increase in parallel during anemia.

Amniotic Fluid↗

PubMed2006

Brain death diagnoses and evaluation of the number of potential organ donors in Quebec hospitals.

PURPOSE: Faced with our inability to respond to the growing number of Quebec patients waiting for organ transplants, we sought to determine the number of potential organ donors (OD) in acute care hospitals. METHODS: A retrospective chart review of all acute care, in-hospital deaths in Quebec in the year 2000 was undertaken. Hospital record librarians provided statistics and completed questionnaires on each chart after applying exclusion and inclusion criteria. RESULTS: There were 24,702 acute care in-hospital deaths reported by 83 hospitals participating in the study on a voluntary basis. Analyzing 2,067 files meeting inclusion criteria, we identified 348 potential OD (1.4% of deaths). In hospitals not providing tertiary adult trauma care, the potential donor rate was 0.99% of all deaths. There were 4.5 times more potential donors in tertiary care adult trauma centers. Brain death was formally diagnosed in 268/348 patients, and organ donation discussed as an option with 230/268 families. Consent for donation was given in 70% of cases, although not all these patients proved to be suitable after evaluation. There were 125 actual donors in Quebec in the year 2000 (18 per million population). CONCLUSIONS: The gap between used and potential donors can be explained by several factors including failure to approach families for organ donation, family refusal, incomplete neurological assessment of patients, and medical unsuitability of some consented donors. There is room for improvement in the identification of potential donors and in the presentation of organ donation as an end of life option to families.

Brain Death↗

PubMed2006

Assessment of clinical reasoning in the context of uncertainty: the effect of variability within the reference panel.

The Script Concordance Test (SCT) assesses reasoning in the context of uncertainty. Because there is no single correct answer, scoring is based on the comparison of answers provided by examinees with those provided by members of a reference panel made up of experienced practitioners. The study aimed to assess the discriminatory power of the SCT based on the variability of the reference panel's answers. Items from a bank covering different family medicine domains were classified into 3 groups according to the degree of variability of answers provided by a pool of experienced doctors. A variability index (mean squared error) was used to select items in the low, moderate and high variability categories. A 102-item test (Cronbach's alpha 0.70), made up of 3 subtests of each category, was administered to 3 contrasting groups in family medicine: 157 clerkship students, 30 residents and 30 practising doctors. anova and effect size (ES) were used to quantify and test the discrimination power of the 3 subtests. The high variability subtest showed high effect size for discrimination between extreme groups (ES = 1.5; F = 16.3, P < 0.001), whereas the moderate variability subtest showed less effect size (ES = 0.56; F = 57, P = 0.041). The low variability subtest did not discriminate significantly (ES = 0.31; F = 2.9, P = 0.06). Variability of answers within the reference panel is a key component of the discriminatory power of the SCT. In accordance with theory, the presence of variability ensures discrimination between levels of clinical experience. These results imply important considerations for the construction of efficient SCTs.

Analysis of Variance↗

PubMed2006

Physician-rated patient preference and patient- and partner-rated preference for tadalafil or sildenafil citrate: results from the Canadian 'Treatment of Erectile Dysfunction' observational study.

OBJECTIVE: To determine physician-based ratings of patient preference, patient preference, partner preference and physician-based assessment of the reasons for patient preference for tadalafil or sildenafil citrate (sildenafil) as a treatment for erectile dysfunction (ED) in routine clinical practice. Phosphodiesterase type 5 inhibitors (PDE5i) are effective and well-tolerated therapies for ED, but patient and partner preferences for these treatments might be determined by many factors, both medical and nonmedical. PATIENTS AND METHODS: The Treatment of ED (TED) observational trial was a multicentre study conducted in Canada to determine patient and partner preferences for the PDE5i tadalafil or sildenafil in routine clinical practice. Patients who planned to change treatment from tadalafil or sildenafil to the alternative drug were invited to participate in the study. The study duration was 4-12 weeks. At visit 1 (baseline), patient background information was collected. At visit 2, physicians answered the physician-rated patient-treatment preference questionnaire, patients answered the treatment preference question (TPQ) and the global assessment question (GAQ), and partners answered the partner TPQ. RESULTS: The TED study was conducted at 266 sites across Canada and involved 2425 patients who used the allowed study medications, and 295 sexual partners who attended clinic visits. More than 98% of patients completed the study. Responses to the preference questionnaires showed that physician-rated patient preference, patient preference, and partner preference had a similar pattern preference, with a significantly higher proportion preferring tadalafil over sildenafil regardless of the change in treatment (i.e. sildenafil to tadalafil or tadalafil to sildenafil). Responses to the GAQ showed that nearly 90% of the patients who took either PDE5i said that the treatment had improved erections. CONCLUSIONS: TED is the first study to assess physician-based ratings of patient preference, patient preference, and partner preference for tadalafil or sildenafil in a routine clinical practice settings. Most participants preferred tadalafil over sildenafil. Understanding the underlying reasons influencing the preference might improve patient compliance and satisfaction with treatment.

Aged↗

PubMed2006

The cognitive validity of the Script Concordance Test: a processing time study.

BACKGROUND: According to the theory on which the Script Concordance Test (SCT) is based, scripts contain expectations on features that are associated with each illness and about the range of values that are typical, atypical, or incompatible. PURPOSE: To document the construct validity of the SCT, we investigated the theory prediction that once a script is activated, new incoming information (e.g., additional clinical features) is processed faster if it is typical for that script than if it is atypical. If it is incompatible, processing time falls in between. METHODS: We presented 2 groups of participants (30 fourth-year medical students and 30 full-time geriatricians) with 64 clinical vignettes (divided over 5 types of prevalent clinical presentations in geriatrics), each accompanied by a diagnostic hypothesis aimed to instantiate an appropriate script. Next, we presented a new finding, which could be typical, atypical, or incompatible given the hypothesis. Participants had to decide as quickly and accurately as possible whether the new finding increased, decreased, of did not affect the likelihood of the diagnostic hypothesis. We administered the test on a computer. The dependent variable was processing time. We analyzed data with a repeated measure 2 x 3 analysis of variance. RESULTS: Typical information was processed faster than atypical and incompatible information (M = 10.6 sec vs. 19.2 sec and 16.4 sec, respectively; p lt; .001 for both). Incompatible information was processed faster than atypical information (16.4 sec vs. 19.2; p < .001). There was no significant difference between the groups of geriatricians and students. CONCLUSION: It is possible to predict what kind of information will be processed faster depending of the typicality and compatibility of clinical data for given hypotheses. Results support SCT construct validity.

Clinical Clerkship↗

PubMed2006

CME workshop in recognizing boundary limits during a medical visit.

BACKGROUND AND OBJECTIVES: Professional boundaries help to establish and maintain the foundation of the doctor-patient relationship. Our objective was to measure physicians' level of awareness in recognizing a boundary limit, their intention to change their behavior regarding boundaries, and their self-reported changes in behavior after participation in an educational workshop, "The Right Distance." METHODS: This longitudinal study used questionnaires to measure the level of awareness of the participants in recognizing boundary limits before and after the workshop and to measure their intention to change their behavior and self-reported behavior changes immediately after the workshop and 6 months later. RESULTS: Before the workshop, the level of awareness in recognizing the boundary limits was 3.9 on a 5.0 point scale in which 5.0 represented the highest level of awareness, and immediately after the workshop it was 4.2/5.0. Female physicians were more aware of these issues. Following the workshop, 51% of participants indicated an intention to change their behavior. On the 6-month follow-up questionnaire, 138 physicians (60%) answered that they had not changed their behavior, and 92 physicians (40%) answered that they had modified their behavior by changing their attitude toward their personal and professional life and toward gifts and gratuities. When the post-workshop and the 6-month follow-up questionnaires were matched, 34 of 57 (60%) participants who stated their intention to change did in fact change their behavior regarding the "right distance." CONCLUSIONS: Boundary issues and level of awareness can be effectively taught in a continuing medical education workshop.

Adult↗

PubMed2005

Optimal population designs for PK models with serial sampling.

In various pharmaceutical applications, repeated measurements are taken from each subject, and model parameters are estimated from the collected data. Examples include dose response modeling and PK/PD studies with serial blood sampling, among others. The quality of the information in an experiment is reflected in the precision of estimates of model parameters, which is traditionally measured by their variance-covariance matrix. In this article, we concentrate on the example of a clinical PK study where multiple blood samples are taken for each enrolled patient, which leads to nonlinear mixed effects regression models with multiple responses. The sampling scheme for each patient is considered a multidimensional point in the space of admissible sampling sequences. We demonstrate how to optimize the precision of parameter estimates by finding the best number and allocation of sampling times. It is shown that a reduced number of samples may be taken without significant loss of precision of parameter estimates. Moreover, our approach allows for taking experimental costs into account, which leads to a more meaningful comparison of sampling schemes and to potential cost savings.

Clinical Trials as Topic↗

PubMed2005

An innovative approach to remedial continuing medical education, 1992-2002.

The authors describe the process of remedial retraining programs organized and planned for Quebec physicians by the College des medecins du Quebec (CMQ) and report the outcomes of these efforts from April 1992 to March 2002. The CMQ (the Quebec medical licensing authority) developed a process to identify physicians who had shortcomings in their clinical performance, determine their educational needs, propose, in collaboration with the four medical schools in the province, personalized retraining programs (clinical training programs, tutorials, focused readings, workshops, and refresher courses), and subsequently evaluate the impact of these retraining programs. During the ten-year period reported, 305 physicians (216 family physicians and 89 specialists) were referred to the Practice Enhancement Division of the CMQ for personalized remedial retraining. The vast majority of these physicians were men (81%). The following difficulties were identified: therapeutic knowledge (37%), diagnostic knowledge (32%), record-keeping (14%), technical skills (10%), clinical judgment (5%), and communication skills (2%). A total of 329 personalized retraining programs were completed: 273 clinical training programs, 41 tutorials, and 15 focused readings. A reevaluation of all these physicians showed that 70% of the retraining programs had succeeded, 15% were partially successful and only 13% had failed. The remaining 2% involved missing data or withdrawal of physicians. The authors conclude that the collaborative CME process described has important and effective original features.

Clinical Competence↗

PubMed2004

GHQ-28 and cGHQ-28: implications of two scoring methods for the GHQ in a primary care setting.

BACKGROUND: The General Health Questionnaire allows for distinguishing patients suffering from psychiatric problems from those in good mental health. There is some controversy as to the best scoring method. Two different methods have been proposed: GHQ and cGHQ. The present study aims at verifying whether there is confirmation of the hypothesis that the population resulting from the cGHQ calculation presents greater chronicity. METHOD: A total of 40 general practitioners and 1145 of their patients in the Greater Montreal area, Québec, Canada participated in the original study. A sub-group of 313 patients were followed over a 3-month period. The patients were asked to complete a set of questionnaires, including the GHQ-28. The traditional method of calculating the GHQ score and the alternative cGHQ method were used. RESULTS: Two discordant groups of patients were identified: Group 1 (acute cases only), positive on the GHQ, but negative on the cGHQ (n = 124), and Group 2 (chronic cases only), negative on the GHQ and positive on the cGHQ (n = 64). Patients in Group 2 were older (p<0.001), were more worried about their health (p = 0.06) and their health problem had lasted for a longer time (p = 0.02). Patients in Group 2 were twice as likely to remain positive on the GHQ and/or the cGHQ as those in Group 1 in the 1- and 3-month follow-ups. CONCLUSIONS: The results suggest the presence of notable differences between the two groups, generally explainable by the hypothesis of greater chronicity in the cGHQ patients. The results confirm the impact of the choice of calculation method on the composition of the two groups. Finally, the authors suggest using the two calculation methods simultaneously.

Adult↗

PubMed2004

ST segment analysis of the fetal electrocardiogram plus electronic fetal heart rate monitoring in labor and its relationship to umbilical cord arterial blood gases.

OBJECTIVE: This study was undertaken to determine the ability of intrapartum electronic fetal heart rate monitoring (EFM) plus fetal electrocardiogram (ECG) ST segment automated ANalysis (STAN, Neoventa Medical, Goteborg, Sweden) monitoring to predict metabolic acidemia (defined as an umbilical cord artery pH < 7.15 and base deficit > or = 12 mmol/L) at birth. STUDY DESIGN: Women with singleton, term pregnancies who had a clinical indication for internal EFM with a fetal scalp electrode were included in the study. Attending physicians were blinded to the ST analysis information, only using available EFM as per current clinical practice. After delivery, 2 trained observers blinded to neonatal outcome and ST analysis information performed visual classification of the EFM tracing in 10-minute epochs according to FIGO guidelines. ST events automatically detected by the STAN S21 monitor (Neoventa Medical) were combined with the visual EFM classification as per STAN clinical guidelines (Neoventa Medical). RESULTS: When applying STAN clinical guidelines from a sample of 143 women, our data indicated a sensitivity of 43%, specificity of 74%, negative predictive value of 96%, and a positive predictive value of 8% for metabolic acidemia at birth. Poor ECG quality, despite good EFM tracings (ECG signal loss), occurred 11% of the tracing time. CONCLUSION: The STAN clinical guidelines have a poor positive predictive value and a sensitivity of less than 50% for metabolic acidemia at birth.

Acidosis↗

PubMed2004

Morphologic alterations in ovine placenta and fetal liver following induced severe placental insufficiency.

OBJECTIVES: Umbilical-placental embolization with microspheres has been used as a model of placental insufficiency and intrauterine growth restriction (IUGR). However, the effects of embolization on placental structure and organ morphology of the resulting IUGR fetus are relatively unexplored. In this study using ovine fetuses, we determined the location and distribution of microspheres within the placenta and explored the extent of placental and fetal organ morphologic changes induced by placental embolization. We hypothesized that microspheres administered into the umbilical circulation over 4 days would cause placental damage without significant morphologic alterations in fetal kidney or liver. METHODS: Eleven pregnant sheep at 118 +/- 1 (SE) days' gestation were studied. In six fetuses, embolization was induced by injections of 15-microm diameter microspheres on 4 successive days into the fetal descending aorta proximal to the umbilical arteries. Five fetuses served as time controls. RESULTS: In embolized fetuses, microspheres were detected in the placenta embedded in the fetal cytotrophoblastic layer or maternal parenchyma adjacent to villous cytotrophoblasts. Fetal cytotrophoblasts appeared normal except for loss of distinct separation between fetal and maternal cell layers. Microspheres were also detected in the fetal membranes within capillaries. The body weights of embolized fetuses were lower than controls, as were the body weight-normalized liver but not kidney weights. In the liver of the embolized fetuses, the number of hematopoietic cell clusters was markedly reduced, whereas the fetal kidneys appeared normal. CONCLUSIONS: We conclude that after 4 days of umbilical-placental embolization, microspheres were concentrated at the fetal villi proximal to the apical maternal-fetal interface and in the fetal membranes. There were noticeable morphologic changes in the embolized placentas, with no apparent gross damage to the placenta. The reduction in fetal liver weight and liver extramedullary hematopoietic cell abundance associated with embolization may predispose the fetus to alterations in liver function that could persist after birth.

Animals↗

PubMed2004

Measurement of perception and interpretation skills during radiology training: utility of the script concordance approach.

Imaging specialties require both perceptual and interpretation skills. Except in very simple cases, data perception and interpretation vary among clinicians. This variability makes for difficulty in measuring these skills with traditional assessment tools. The script concordance approach is conceived to allow standardized assessment in contexts of uncertainty. In this exploratory study, the authors tested the usefulness of the approach for assessment of perceptual and interpretation skills in radiology. A perception test (PT) and an interpretation test (IT) were designed according to the approach. Both tests used plain chest X-rays. Three groups were tested: clerkship students (20), junior residents (R1-R3; 20), senior residents (R4-R5; 20). Eleven certified radiologists, all currently appointed to chest reading, provided the answers by aggregate scoring method. Statistics included descriptive, ANOVA, regression analysis, Pearson and Spearman correlation coefficients. Cronbach alpha values were 0.79 and 0.81 for the PT and IT respectively. Score progression was statistically significant in both tests. Perception scores progressed more rapidly than interpretation scores during training. Effect size was large in discriminating low versus higher level of expertise, 2.2 (PT) and 1.6 (IT). The Pearson correlation coefficient between both tests was 0.58. Cronbach alpha coefficient values indicate reasonable reliability for both tests. The linear progression of scores, each at its own pace, and the positive and moderate magnitude of the Pearson correlation coefficient are arguments suggesting measurement of two different skills. More studies are necessary to document the approach usefulness for assessment in radiology training.

Clinical Competence↗

PubMed2003

Placental insufficiency and its consequences.

Placental insufficiency is a process leading to progressive deterioration in placental function and a decrease in transplacental transfer of oxygen and nutrients to the fetus. The resulting fetal hypoxemia is the major stimulus involved in the reduction in fetal growth as an attempt to reduce metabolic demands by the growing fetus. Fetal growth restriction (FGR) is the second cause of perinatal death after prematurity and can complicate up to 6% of all pregnancies. It is becoming apparent that its occurrence has major impacts on the fetus and placenta with consequences on the cardiovascular, metabolic and neurological development up to adulthood. We are just starting to unveil some of the basic mechanisms involved in this complex adaptation that may lead to reprogramming of fetal organs development mostly the heart, pancreas, lungs and brain. It is becoming clear that future research is needed to develop strategies to improve antenatal detection of FGR, in addition to reduce the risk of abnormal neurodevelopment during childhood, and onset of common diseases in adulthood following pregnancies complicated with placental insufficiency.

Animals↗

PubMed2003

Intrapartum computerized fetal heart rate parameters and metabolic acidosis at birth.

OBJECTIVE: To estimate to what extent computerized fetal heart rate (FHR) parameters are affected by labor and to estimate the relationship between FHR parameters and the degree of fetal metabolic acidosis in laboring patients at term. METHODS: Fifty-one women between 37 and 42 weeks' gestational age were recruited prospectively in the following groups: 1) nonlaboring women, and 2) laboring women requiring fetal scalp electrode for continuous electronic FHR monitoring. Computerized FHR analysis was performed for 1 hour within 6 hours of delivery in the nonlaboring group and continuously throughout labor in the laboring group. Multiple linear regression analysis was used to determine the relationship between individual FHR parameters during the last hour before delivery and the degree of metabolic acidosis at birth. RESULTS: The umbilical cord artery base excess and pH did not show any significant correlation with any of the computer-derived FHR parameters studied. Both umbilical cord venous base excess and pH were inversely related to the number of large FHR decelerations (r = -.46, P <.01 and r = -.56, P <.01, respectively). Labor was associated with a 31% increase in both short- and long-term FHR variation in the reassuring FHR tracing group when compared with nonlaboring women. Although this increase in FHR variation was not seen in the nonreassuring FHR tracing group, there was no relationship to the degree of metabolic acidosis at birth. CONCLUSION: In term pregnant women with reassuring FHR tracing, labor causes an increase in both short- and long-term FHR variation, which was abolished in the presence of nonreassuring FHR tracing. Computer-derived FHR parameters studied during the last hour of labor were not correlated with the degree of metabolic acidosis as measured in the umbilical artery at birth.

Acidosis↗

PubMed2003

RETIRED: The use of first trimester ultrasound.

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

Female↗

PubMed2003

Intrauterine herpes simplex infection.

Neonatal herpes simplex virus (HSV) infection is usually acquired at birth. We present an infant with intrauterine HSV infection acquired after rupture of membranes. The infant was born prematurely to a woman with a first episode of genital herpetic infection in early pregnancy and rupture of membranes 11 days prior to delivery. The infant, at delivery had extensive brain damage, hemorrhage, and cystic encephalomalacia due to herpes infection. On 2nd day of life, Magnetic Resonance Imaging, suggested that the hemorrhage had occurred 7 to 14 days before the scan and the placental pathology was supportive of an ascending infection. The case of an ascending herpetic intrauterine infection after rupture of the membranes raises the question of prevention and suppressive antiviral therapy.

Abnormalities, Multiple↗

PubMed2003

The risks of adverse neonatal outcome among preterm small for gestational age infants according to neonatal versus fetal growth standards.

OBJECTIVE: To evaluate neonatal and fetal growth standards in determining the impact of small for gestational age (SGA) on neonatal mortality and morbidity. DESIGN: A hospital-based cohort study of infants born in a regional tertiary care center and admitted to the neonatal intensive care unit. SETTING AND PARTICIPANTS: A total of 1267 singleton neonates of <34 weeks gestational age, without any congenital anomalies, born between January 1, 1993 and December 31, 2001. OUTCOME MEASURES: Each outcome variable including mortality, respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage (IVH), periventricular leukomalacia, and necrotizing enterocolitis was related to growth status as defined by fetal and neonatal growth standards after adjustment for potential confounders. RESULTS: The number of SGA infants was 11.6% (n = 147) of the study population according to neonatal growth standards, but it was increased to 23.3% (n = 295) when fetal growth standards were used. According to fetal growth standards, when SGA was compared with appropriate for gestational age infants, it was associated with an increased risk of respiratory distress syndrome (odds ratio [OR] 1.40; 95% confidence interval [CI] 1.00-1.95), bronchopulmonary dysplasia (OR 2.18; 95% CI 1.33-3.59), IVH (OR 1.67; 95% CI 1.13-2.45), and retinopathy of prematurity (OR 3.88; 95% CI 2.33-6.48). However, only neonatal mortality (OR 3.64; 95% CI 1.64-8.09), retinopathy of prematurity (OR 5.38; 95% CI 2.87-10.90), and necrotizing enterocolitis (OR 2.47; 95% CI 1.21-5.07) were positively associated with SGA when using neonatal growth standards. CONCLUSIONS: Compared with the neonatal growth standards, the fetal growth standards are better in identifying increased risk of respiratory morbidity and IVH among preterm SGA infants.

Cohort Studies↗

PubMed2003

The use of fetal Doppler in obstetrics.

OBJECTIVE: To develop national guidelines on the use of fetal Doppler in obstetrics. OPTIONS: Whether umbilical cord artery, umbilical cord venous, ductus venosus, and middle cerebral artery Doppler are useful in assessing fetal health. OUTCOME: Prediction of adverse perinatal outcome or prediction of fetal anemia. EVIDENCE: MEDLINE search and review of bibliographies in identified articles. VALUES: The evidence was reviewed by the Diagnostic Imaging Committee and the principal authors. A quality of evidence assessment was undertaken as outlined in the report of the Canadian Task Force on the Periodic Health Examination. BENEFITS, HARMS, AND COSTS: Intrauterine growth restriction complicates 5% to 10% of all pregnancies and up to 30% of multiple pregnancies. In 60% of these pregnancies, the primary cause is placental insufficiency. Improvement in the identification of the fetus at risk of intrauterine demise may lead to more successful management strategies. Management of fetal red blood cell isoimmunization requires a prediction of fetal anemia. If invasive procedures to predict fetal anemia can be replaced with noninvasive tests, fetal morbidity and mortality can be reduced. RECOMMENDATIONS: 1. Umbilical artery Doppler should be available for assessment of the fetal-placental circulation in pregnant women with suspected severe placental insufficiency. (I-A) 2. Depending on other clinical factors, reduced, absent, or reversed umbilical artery end-diastolic flow is an indication for enhanced fetal surveillance or delivery. If delivery is delayed to enhance fetal lung maturity with maternal administration of glucocorticoid, intensive fetal surveillance until delivery is suggested for those fetuses with reversed end-diastolic flow. (II-1B) 3. Umbilical artery Doppler should not be used as a screening tool in healthy pregnancies, as it has not been shown to be of value in this group. (I-A) 4. Umbilical venous double pulsations, in the presence of abnormal umbilical artery Doppler waveforms, necessitate a detailed assessment of fetal health status. (II-3B) 5. Measurement of the fetal middle cerebral artery Doppler peak systolic flow velocity is a predictor of moderate or severe fetal anemia and can be used to avoid unnecessary invasive procedures in pregnancies complicated with red blood cell isoimmunization. (II-1A) 6. Since inaccurate information concerning fetal Doppler studies could lead to inappropriate clinical decisions, it is imperative that measurements be undertaken and interpreted by expert operators who are knowledgeable about the significance of Doppler changes and who practise appropriate techniques. Duplex mode with pulsed Doppler and colour Doppler flow mapping is the minimum required ultrasound equipment. (II-1A)

Blood Flow Velocity↗