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Biomedical subjects

C R Harman

Publications and source records attributed to C R Harman.

At least 37 records · Page 2Linked to original sources
PubMed1999

Problems in the detection of intrapartum fetal asphyxia with intermittent auscultation.

We present 4 cases of severe intrapartum fetal asphyxia occurring during spontaneous unaugmented labours at term in low-risk women. In each case the baseline heart rate was completely normal, and the only indication of asphyxia was markedly decreased variability detected with electronic fetal heart rate monitoring. Correct action was taken in 3 cases that probably prevented fetal death or reduced neonatal morbidity. In no case would intermittent auscultation have been able to identify the compromised fetus.

Adolescent↗
PubMed1998

Fetal assessment based on fetal biophysical profile scoring. VIII. The incidence of cerebral palsy in tested and untested perinates.

OBJECTIVE: The intent of this comparative clinical study was fourfold: (1) to determine the incidence of cerebral palsy in a large obstetric population, (2) to compare the incidence of cerebral palsy in patients at high risk referred for and managed according to the fetal biophysical profile score result with the incidence among unreferred and untested patients, (3) to determine the relationship, if any, between the last fetal biophysical profile score and the incidence of cerebral palsy, and (4) to categorize cases of cerebral palsy according to the clinical parameters and the probable time and nature of the damaging insult. STUDY DESIGN: In this retrospective 5-year comparative study (1987 to 1991) the incidence of cerebral palsy was determined by analysis of International Classification of Diseases, Ninth Revision, -coded related medical services. The clinical records were then sought and reviewed in index cases and obstetric, neonatal, and postnatal clinical data were abstracted. Cross-correlation with partial registries was done to confirm completeness of capture of index cases. The population of referred high-risk patients who received serial fetal biophysical profile scoring and were managed according to test results was determined by review of a prospective computer-stored database and by review of patient log books. The population of untested patients was calculated as the residual of total cases minus tested cases. The rate of cerebral palsy for all patients and for the tested and untested population was calculated and compared. The tested and untested perinates were compared for birth age, weight, and assigned timing or etiology of cerebral palsy. In the tested population the distribution of test results by last recorded biophysical profile score was determined and the relationship between the last test result and cerebral palsy and predictive accuracy parameters of the fetal biophysical profile score were calculated. RESULTS: The incidence of cerebral palsy among the 84,947 live births was 3.68 per 1000 live births (313 cases). The rate of cerebral palsy in the 26,290 referred high-risk tested patients was 1.33 per 1000 (35 cases) compared with a rate of 4.74 per 1000 live births in the 58,657 untested mixed low-risk/high-risk patients (278 cases). These differences were highly significant. A significant declining trend in the annual incidence of cerebral palsy was observed in the total population and the untested population, whereas the rate in the tested population remained relatively constant over the 5-year study interval. The differences in the cerebral palsy rate between the tested and untested population were not related to differences in gestational age, birth weight, or assigned timing or etiology category. In the tested population the relationship between the incidence of cerebral palsy and the last test fetal biophysical profile score was inverse, exponential, and highly significant. CONCLUSIONS: Antepartum assessment by fetal biophysical profile scoring is associated with a significant reduction in the incidence of cerebral palsy compared with untested patients. The relationship between the last test score and the incidence of cerebral palsy is inverse and exponential, suggesting that antenatal asphyxia is an important and potentially avoidable cause of cerebral palsy.

Birth Weight↗
PubMed1998

Fetal coronary and cerebral blood flow in acute fetomaternal hemorrhage.

A fetal heart rate tracing with absent variation and a sinusoidal pattern led to the diagnosis of acute fetomaternal hemorrhage at 29 + 2 weeks' gestation. The middle cerebral artery had increased peak blood flow velocity with reversed end-diastolic flow. Fetal coronary arteries visualized by color-coded and pulsed wave Doppler sonography showed slight decrease of time-averaged maximum velocities after oxygen administration, while cerebral flows remained unchanged. After administration of 50 ml blood (pre-transfusion hematocrit < 11%) the middle cerebral artery flow normalized and coronary artery velocities decreased further until coronary blood flow could no longer be visualized within 30 min of the transfusion (post-transfusion hematocrit 27%). Evidence of successful fetal resuscitation also included normalization of the fetal heart rate tracing and resumption of fetal activity (biophysical profile score 8/10). This was also observed after a second transfusion of 38 ml blood. Deterioration from repeated fetomaternal hemorrhage led to delivery of a severely anemic neonate (cord hematocrit 7%) by Cesarean section. Postnatally, a single seizure, moderate severity respiratory distress syndrome and grade III intraventricular hemorrhage were noted. Increased peak blood flow velocity with reversed end-diastolic flow may be observed in the middle cerebral artery of fetuses with acute anemia. Correction of this phenomenon with transfusion suggests that hypovolemia and low blood viscosity are major contributing factors. Furthermore, decreasing coronary artery blood flow velocities with supplemental oxygen and blood replacement confirm functional autoregulation of the fetal coronary circulation. Observation of these acute flow changes during fetal surveillance warrants investigation for a potentially serious underlying condition.

Acute Disease↗
PubMed1998

Indications, technique, and efficacy of alcohol injection of enlarged parathyroid glands in patients with primary hyperparathyroidism.

BACKGROUND: Percutaneous alcohol ablation of the parathyroid gland (PAAP) has been proposed as an alternative treatment for primary hyperparathyroidism in patients unsuitable for surgery. The current study aimed to determine the (1) selection criteria, (2) associated morbidity, and (3) efficacy of PAAP. METHODS: From 1987 to 1998, 36 patients with primary hyperparathyroidism (mean age 65 years) underwent PAAP. The indications for PAAP were (1) medical comorbidity, (2) technically unsafe reoperative surgery, (3) partial ablation of a single remaining gland, and (4) patient choice. RESULTS: There were no long-term complications. Two patients had temporary recurrent laryngeal nerve injury and 4 had temporary hypocalcemia. Over a median follow-up of 16 months, 12 (33%) of the patients remained eucalcemic. For analysis purposes patients were separated into 2 separate groups: 29 with attempted complete ablation and 7 with partial ablation of a single remaining gland only. Ten of the complete ablation group (34%) remained eucalcemic. In the partial ablation group only 2 remained eucalcemic, but all had adequately controlled serum calcium levels. CONCLUSION: PAAP should be considered for hyperparathyroid patients with excessive reoperative morbidity or prohibitive medical comorbidity or those in whom the intent is to partially ablate a single remaining enlarged gland. In these patients close follow-up of serum calcium is required, and repeat treatments may be necessary because recurrence of hypercalcemia is likely.

Adult↗
PubMed1998

Coronary blood flow in fetuses with intrauterine growth restriction.

The coronary circulation is the major determinant of myocardial oxygen balance which in turn is necessary for adequate cardiac function under a variety of conditions. Experiments in the fetal lamb suggest short-term functional coronary autoregulation in response to increase in afterload and acute hypoxemia. Long-term, acute-on-chronic hypoxemia is associated with a marked increase of maximal myocardial flow reserve suggesting coronary vascular angio-neogenesis during the period of chronic hypoxemia. In the human fetus, flow velocity waveforms from the coronary arteries may be obtained by color-coded and pulsed wave Doppler sonography in normally developed fetuses from 31 weeks of gestation onwards under favorable imaging conditions. Coronary blood flow may also be visualized in selected fetuses with intrauterine growth restriction, absent or reversed end-diastolic flow in the umbilical artery, cephalization of blood flow and abnormal flow patterns in the precordial veins and the umbilical vein. In these fetuses visualization of coronary blood flow may be possible as early as 26 weeks gestation and is consistently associated with a significant increase in the peak velocity index for veins in the ductus venosus. In this circulatory state, visualization of coronary blood flow is suddenly very easy. This "visualization threshold" may be a sign of maximal increase in coronary blood flow in an attempt to "spare" the fetal heart of hypoxemia. Although highly operator dependent, demonstration of coronary blood flow in intrauterine growth restriction identifies fetuses at high risk for intrauterine fetal death and postpartum circulatory failure.

Animals↗
PubMed1997

Fetal surveillance in diabetic pregnancy.

The focus of monitoring in diabetic pregnancy is no longer the prevention of fetal mortality, owing to the impressive benefits of strict maternal glucose control. Against this background, fetal monitoring must account for congenital anomalies, fetal mortality and severe morbidity as a result of metabolic consequences of hyperinsulinism, the exponential effect of diabetes when other maternal complications are present, and peripartum problems of the macrosomic infant, of delayed lung maturation, birth trauma and neonatal hypoglycemia. Thus, a broad range of potential fetal problems with varying maternal complications requires individualized, serial observation with multiple-format, properly validated tests. There has been recent progress: definition of the population at risk, clarification of pathophysiology, application of multiple-format tests, and evaluation of neonatal impacts; further precision may be developed with specific fetal tests. This review deals with the continued fine tuning of this critical area of perinatal medicine.

Amniotic Fluid↗
PubMed1997

Fetal assessment based on the fetal biophysical profile score: relationship of last BPS result to subsequent cerebral palsy.

OBJECTIVE: The prime intent of this study was to determine the relationship if any between the last fetal biophysical profile score and the risk of cerebral palsy at age 3 years. The secondary objective was to examine the clinical characteristics of infants with cerebral palsy whose obstetric management included serial fetal biophysical profile scores. STUDY DESIGN: The incidence of a high risk pregnant population whose antenatal assessment was by serial fetal biophysical profile scoring was determined by cross-referencing two discrete data bases. The completeness and reliability of the data bases was confirmed by secondary audit. Obstetrical, neonatal and post-natal clinical records of index cases of cerebral palsy were subsequently reviewed, categorized and analyzed. RESULTS: Fetal biophysical profile scores (BPS) were recorded in 22,336 high risk pregnancies: 27 patients delivered an infant subsequently identified as having cerebral palsy (rate 1.21 per 1000). The relationship between last BPS result and cerebral palsy was inverse, exponential and highly significant (R2 = 0.987; p < 0.001). Affected infants with a last abnormal BPS result were significantly more likely to exhibit fetal distress (88.8%), acidosis (77.7%), and have neonatal seizures (88.8%). Antenatal asphyxia was the apparent cause of cerebral damage in 29.6% of cases. CONCLUSION: The last fetal biophysical profile score is a predictor of the risk of cerebral palsy.

Cerebral Palsy↗
PubMed1996

A familial disorder with duodenal atresia and tetralogy of Fallot.

We report on two sibs with tetralogy of Fallot (TOF) and duodenal atresia (DA). The first child, a 6-year-old girl, had a right facial palsy in addition to the TOF and DA. Her brother, age 10 months, was born with bilateral microtia without facial palsy. The children are the product of an apparently non-consanguineous union between clinically normal parents. The pertinent family history includes a paternal aunt with TOF and a cleft lip and palate who died in childhood and another paternal aunt with a supernumerary thumb. This family has anomalies found in several syndromes, but does not meet the diagnostic criteria for any of them. The genetic basis for this condition remains unknown, but the pattern of inheritance is likely either autosomal recessive, or autosomal dominant with variable expression and reduced penetrance. The pathogenesis is unknown, but either a disturbance in neural crest cell migration or familial predisposition to vascular disruption might explain this pattern of malformations.

Child↗
PubMed1995

Prenatal diagnosis of ring chromosome 6.

An amniocentesis was performed on a gravida 1, para 0 23-year-old female because of high maternal serum alpha-fetoprotein and nuchal thickening/cystic mass apparent on the fetal ultrasound. Detailed ultrasound examination revealed multiple anomalies including brain abnormalities. The fetus was found to have a mosaic female karyotype: 45,XX, - 6/46,XX,r(6) (p25q27) (62 per cent:38 per cent). This is the first report of a prenatally diagnosed case of ring chromosome 6.

Adult↗
PubMed1995

Impact of a nurses' strike on the cesarean birth rate.

OBJECTIVE: Our purpose is to describe the impact of a 31-day nurses' strike on the cesarean birth rate in the province of Manitoba, Canada. STUDY DESIGN: Computerized hospital records, obtained for all births over a 24-month period, were used to identify complications of labor indicating cesarean section, method of delivery, and adverse maternal and newborn outcomes. The strike interval was compared with a 16-month prestrike period. RESULTS: The cesarean section rate in the strike interval, 12.5 per 100 deliveries, was significantly lower than the prestrike rate of 14.6 per 100 deliveries (p < 0.05). Reductions occurred primarily among breech deliveries and among women with a previous cesarean section. No differences were observed in the rates of individual adverse maternal or newborn outcomes. However, the pooled incidence of adverse newborn outcomes was significantly higher during the strike than during the prestrike period (10.2 vs 8.1/100 deliveries, odds ratio 1.27, 95% confidence interval 1.07 to 1.52). CONCLUSION: In response to constraints imposed by a reduced nursing complement, physicians increased the frequency of vaginal birth in breech presentation and among women with previous cesarean section.

Breech Presentation↗
PubMed1994

Life without amniocentesis: elevated maternal serum alpha-fetoprotein in the Manitoba program 1986-91.

Pregnant women demonstrating an elevated maternal serum alpha-fetoprotein level are at increased risk for fetal neural tube defect or other anomaly. Diagnostic procedures to evaluate these pregnancies include high-resolution ultrasound and amniocentesis to measure amniotic fluid levels of alpha-fetoprotein and N-acetylcholinesterase. We wished to examine the efficacy of detailed ultrasound examination alone, in evaluation of women with 'unexplained' elevation of maternal serum alpha-fetoprotein. The results showed that no neural tube defects were missed in the assessment of 1325 pregnancies with a raised level of maternal serum alpha-fetoprotein over 6 years, despite complete reliance on ultrasound in 98%. Detailed fetal ultrasound evaluation by experienced personnel is adequate to identify all cases of neural tube defects in a selected high-risk population.

Journal Article↗
PubMed1994

Elevated MSAFP levels and congenital heart defects: lack of an association.

This study was undertaken to evaluate the relationship between elevated maternal serum alpha fetoprotein (MSAFP) levels and congenital heart defects. Thirty-two infants with isolated major congenital heart defects and whose mothers had had MSAFP screening were identified. In only one case was the MSAFP greater than 2.3 multiples of the median. A review of our experience with women with elevated MSAFP levels did not document a higher rate of congenital heart malformations than would be expected based on estimated frequencies in the general population.

Biomarkers↗
PubMed1994

MSAFP levels and oesophageal atresia.

This study was undertaken to evaluate the relationship between maternal serum alpha-fetoprotein (MSAFP) levels and oesophageal atresia (OA). OA occurred in 16 fetuses of mothers who had an MSAFP test in the study interval. The multiple of the median (MOM) value for MSAFP averaged 1.54 +/- 0.65 (range 0.5-2.9 MOM), which was significantly higher than the value seen in controls. The median MOM was 1.35. Using a cut-off of 2.5 MOM, the sensitivity of MSAFP for detecting OA was 19 per cent. Although OA should be considered in the differential diagnosis of an elevated MSAFP level, MSAFP cannot be considered an appropriate screening test for OA given the low sensitivity.

Esophageal Atresia↗
PubMed1994

Fetomaternal hemorrhage following funipuncture: increase in severity of maternal red-cell alloimmunization.

OBJECTIVE: To determine the prevalence of fetomaternal transplacental hemorrhage after funipuncture and its effect on maternal red-cell alloantibody levels. METHODS: The prevalence and size of transplacental hemorrhages at the Health Sciences Centre were studied in two groups of patients: 174 women who were not alloimmunized or were carrying fetuses whose red cells were negative for the antigen to which they were immunized, and 122 women who were alloimmunized and carrying fetuses whose red cells were positive for the antigen to which they were immunized. In the alloimmunized group with affected fetuses, we surveyed the incidence of maternal antibody increase in titer by two or more doubling dilutions and the Rh(D) antibody increase (in microgram/mL of serum) of more than 50% after funipuncture. RESULTS: One hundred of the 174 women (57.5%) in the nonimmunized group and 69 of the 122 women (56.6%) in the immunized group had evidence of transplacental hemorrhages ranging in volume from 0.03 mL to greater than 5 mL of fetal red blood cells. In the latter group, antibody titer increases of 2 to 9 and doubling dilutions occurred in 37 of 74 women (50%) in whom such measurements were carried out. Increases of anti-D exceeding 50% occurred in 44 of 53 women (83%) in whom quantitative measurements were assayed. CONCLUSION: Funipuncture carries a high risk of fetal transplacental hemorrhage. In the immunized woman carrying an antigen-positive fetus, this will increase the level of her antibody and probably increase the severity of hemolytic disease in her fetus. In alloimmunized women, funipuncture should rarely be carried out to determine the fetal antigen status. Serial amniocenteses combined with careful serial ultrasound observation of the fetus are safer. Funipuncture should not be done in alloimmunized women before the cord vessels are of adequate size to allow immediate intravascular fetal transfusion, if required.

Blood Group Antigens↗
PubMed1993

Fetal biophysical profile score. VI. Correlation with antepartum umbilical venous fetal pH.

OBJECTIVE: Our objective was to determine the relationship, if any, between the fetal biophysical profile score and antepartum umbilical venous pH. STUDY DESIGN: This was a prospective observational study conducted concurrently in two centers and involving two discrete high-risk groups of fetuses. Fetal biophysical profile scores were compared with umbilical venous pH values measured in blood obtained by immediate cordocentesis. A total of 493 paired observations of biophysical profile score and pH were made; 104 observations were of fetuses with intrauterine growth retardation and 389 observations were of fetuses with alloimmune anemia. RESULTS: In both data sets there was a highly significant linear correlation between biophysical profile score and umbilical venous pH. Poor biophysical profile score performance (a score of 0 of 10) was always associated with a pH < 7.20, whereas the pH was always > 7.20 when the biophysical profile score was 10 of 10. Sequenced sensitivity of short-term biophysical variables in the detection of acidemia was observed. CONCLUSION: The fetal biophysical profile score accurately predicts antepartum umbilical venous pH.

Analysis of Variance↗
PubMed1992

Severe anti-C hemolytic disease of the newborn.

OBJECTIVE: Because of referral of a C-alloimmunized pregnant woman with a previous hydropic death whose fetus survived after four intraperitoneal transfusions, prevalence and severity of anti-C hemolytic disease of the newborn were investigated. STUDY DESIGN: The numbers of C- or Ce-alloimmunized pregnancies in Manitoban women and their outcome for the 28-year period ending Oct. 31, 1990, were reviewed. The literature relating to C or Ce alloimmunization from 1944 to 1990 was surveyed. RESULTS: In Manitoba for the period reviewed there were 120 pregnancies in 80 C- or Ce-alloimmunized women. Twenty-two ended in abortion and two in fetal death unrelated to anti-C or anti-Ce. Of the remaining 96, 33 fetuses of 32 pregnancies were affected but only eight (6.7%) required treatment after birth. None were severely affected. In the literature there are only three other reported deaths from C or Ce hemolytic disease; two of the three may have been the same patient. The prevalence of C or Ce alloimmunization reported in various series, including our own, ranged from 8.7 to 185 per 100,000 pregnancies. CONCLUSIONS: Because on rare occasions, C or Ce alloimmunization can cause severe hemolytic disease, criteria for investigative measures such as amniocentesis or cordocentesis do not differ from the criteria for instituting these measures in Rho (D)-alloimmunized pregnancies.

Erythroblastosis, Fetal↗
PubMed1992

Must macrosomic fetuses be delivered by a caesarean section? A review of outcome for 786 babies greater than or equal to 4,500 g.

Because difficult vaginal delivery is more frequent with macrosomic fetuses, some writers recommend routine Caesarean section for the delivery of fetuses greater than or equal to 4,500 g. The purpose of this study was to evaluate the appropriateness of this recommendation. A retrospective review was undertaken to determine how many fetuses born in our hospital weighing greater than or equal to 4,500 g died or were permanently damaged as a consequence of mechanical difficulties at delivery. During a 10-year period, 590 (75%) of 786 cephalic babies weighing greater than or equal to 4,500 g and alive at the start of labour were born vaginally. No baby died or was permanently damaged as a consequence of mechanical difficulties at delivery. Routine Caesarean section for macrosomic fetuses to prevent death or damage from difficult delivery is not warranted by our results.

Birth Weight↗