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Biomedical subjects

R F Hume

Publications and source records attributed to R F Hume.

At least 37 records · Page 2Linked to original sources

Parental decisions to terminate/continue following abnormal cytogenetic prenatal diagnosis: "what" is still more important than "when".

This study was undertaken to determine if parental decisions to continue or terminate following the diagnosis of a cytogenetic abnormality have changed over the past 8 years at the same center. Parental decisions in 310 prenatal chromosomal abnormalities were stratified by procedure (chorionic villus sampling [CVS] vs. amniocentesis) and the severity of the anomaly (severe vs mild-moderate). Patients with severe anomalies were much more likely to terminate regardless of gestational age. There was a trend (P = .107) toward a lower rate of termination for mild-moderate degrees in the second trimester. There was no change in patient's decisions over time. Patients' decisions about termination are focused on the severity of the disorder and only marginally influenced by when in gestation the decision is made.

Abortion, Eugenic↗

Aneuploidy among prenatally detected neural tube defects.

We have reported previously a 10% aneuploidy detection rate among 39 cases of fetal neural tube defects (NTD). Subsequently we amassed an additional experience of over 17,000 prenatal diagnosis cases over a 5-year period. During this period 106 cases of NTDs were identified; 44 with anencephaly, 62 with open spina bifida. The average maternal age of this population with NTDs was 29 years (15-40); 6 patients declined amniocentesis. Six of 100 cytogenetic studies were aneuploid; one anencephalic fetus had inherited a maternal marker chromosome, and 5 NTD cases had trisomy 18. The average maternal age of the aneuploid cases was 31 (19-40); 3 were 35 years or older. Four of 5 trisomy 18 cases had multiple congenital anomalies (MCA). The overall aneuploidy detection rate in our cohort was 5-6%, while aneuploidy occurred in 2% of the isolated NTD cases, and 24% of the MCA cases. Combining the earlier experience, 4/39 aneuploidy (2 trisomy 18, 4p+, del 13q) yields an aneuploidy detection frequency of 10/145 (7%), of which most (7/10) had trisomy 18. These data support fetal karyotyping for accurate diagnosis, prognosis, and recurrence-risk counseling.

Adolescent↗

Second-trimester minor ultrasound anomalies: impact on the risk of aneuploidy associated with advanced maternal age.

OBJECTIVE: To determine the impact of the presence or absence of minor ultrasound anomalies for the risk of aneuploidy in patients already at high risk because of advanced maternal age. METHODS: Eleven hundred forty-four women having amniocentesis for advanced maternal age were divided into those with minor ultrasound anomalies (n = 62) and those without (n = 1082). Two hundred fifty-nine women younger than 35 years but with minor anomalies on ultrasound were also included. RESULTS: Fetal aneuploidy was found in six of 62 (9.7%) women of advanced maternal age with minor ultrasound anomalies, in five of 1082 (0.5%) women older than 35 years with normal ultrasound results, and in five of 259 (1.9%) women younger than 35 years with minor ultrasound anomalies. CONCLUSION: Minor ultrasound anomalies increase considerably the risk of aneuploidy in women older than 35 years, and their absence lowers that risk slightly. Minor ultrasound anomalies in the fetuses of women younger than 35 raises their risk to that of a 39-year-old women in her second trimester. Ultrasound can be used to modify genetic risks at counseling and may help patients in their decision to have invasive testing.

Adult↗

Integration of genetics and ultrasonography in prenatal diagnosis: just looking is not enough.

OBJECTIVE: There has been a gradual shift of the focus of prenatal diagnosis from genetics to ultrasonography. We assessed our primary genetics approach to determine what would be missed without the genetics component. STUDY DESIGN: We evaluated referral indications for patients with normal and abnormal prenatal findings from Jan. 1, 1990, to March 31, 1995, and categorized them according to type of fetal anomalies and genetic abnormalities found. Discordance among initial indication, identified risk factors, and observed abnormalities was assessed. RESULTS: The proportion of patients referred for very-high-risk indications increased over time; 13.5% of all patients (1992 of 14,725) had abnormalities. Abnormal outcomes were categorized as 26% chromosomal, 58% ultrasonographic dysmorphologic features, 11% biochemical or deoxyribonucleic acid disorders, 5% infectious, and 11% other. Of the cases of ultrasonographic dysmorphism (exclusive of the aneuploidies), 3.5% were ultimately determined to be syndromic and 2.5% to be discrepant, that is, having a different abnormality than the referred diagnosis. Including the whole spectrum of disorders seen, half of the abnormalities would not be detectable with even high-quality ultrasonography. CONCLUSION: A large number of abnormal findings were not consistent with initial indication for referral. Correct diagnosis depended on increased acuity provided by genetic pedigree analysis and recognition of syndromes. Diligence in the search for associated anomalies, aneuploidy, pedigree analysis, and syndromic abnormalities remain critical components in the differential diagnosis. The elucidation of unexpected findings suggests the advantages of early counseling and a genetics-based approach combined with tertiary rather than primary ultrasonography with counseling only when anomalies are detected.

Amniocentesis↗

Abnormal nuchal findings on screening ultrasonography: aneuploidy stratification on the basis of ultrasonographic anomaly and gestational age at detection.

OBJECTIVE: Our purpose was to determine the specific likelihood of different aneuploidies by gestational age in patients with nuchal folds and simple and septated nuchal membranes. STUDY DESIGN: Retrospective database analysis was performed of 158 consecutive patients with a nuchal fold or simple or septated nuchal membrane on either abdominal or vaginal ultrasonography. RESULTS: Thirty-eight patients with nuchal folds, 65 with simple nuchal membranes, and 55 with septated nuchal membranes were evaluated. Septated nuchal membranes were associated with the highest incidence of karyotypic abnormalities (> 50%). A peak incidence of trisomy 21 (27%) was found in the early midtrimester, leveling off to 11% by the late midtrimester. The late first trimester had a high incidence of trisomy 18 (22%), occurring more frequently than 45,X. CONCLUSION: Ultrasonographic anomalies in the posterior neck are associated with aneuploidy from 21% to 58% of the patients in this selected population. Each anomaly has different risks for aneuploidy type, varying with gestational age at diagnosis.

Aneuploidy↗

Faint and positive amniotic fluid acetylcholinesterase with a normal sonogram.

OBJECTIVE: Both faint and positive amniotic fluid acetylcholinesterase determinations have been associated with fetal abnormalities. We evaluated the effect of a normal sonogram and positive or faint acetylcholinesterase level on the risk for anomalies. STUDY DESIGN: Between Jan. 1, 1989, and Feb. 1, 1995, 4859 amniocenteses were performed. Twenty-three cases of abnormal acetylcholinesterase determinations combined with normal sonograms were identified, and pregnancy outcomes were determined. RESULTS: One abnormal karyotype was identified (45,X/47,XXX mosaic). No neural tube defects were seen in infants with an abnormal acetylcholinesterase determination and normal sonogram. One fetus of a twin pregnancy had a ventral wall defect that was not detected on ultrasonography. Seventy-three percent of infants were normal at birth, but 27% of the pregnancies had abnormal outcomes. CONCLUSIONS: Advances in ultrasonography have led to improved detection of fetal abnormalities. With a normal karyotype, repeat invasive testing may not be necessary.

Acetylcholinesterase↗

Histopathology of fetal diastrophic dysplasia.

We report on three cases of diastrophic dysplasia in second trimester fetuses and discuss the differential diagnosis and clinical, radiologic, and histopathologic findings. Manifestations of typical diastrophic dysplasia in infants and older patients include abnormal pinnae, scoliosis, and joint contractures; these were absent in the fetuses, in keeping with the tendency for the clinical and radiologic aspects of this disease to become more severe with age. The histopathologic characteristics of the cartilage appear to be similar in the fetus and older patient, and therefore may be useful in differentiating diastrophic dysplasia from other osteochondrodysplasias in the second trimester.

Cartilage↗

Sequential urinalysis improves evaluation of fetal renal function in obstructive uropathy.

OBJECTIVES: The purpose of our study was to determine whether sequential vesicocenteses improve the evaluation of renal damage, compared with single urine sampling in obstructive uropathy. STUDY DESIGN: A total of 29 fetuses with complete obstructive uropathy underwent a minimum of three sequential complete vesicocenteses at 48- to 72-hour intervals. First and last urine values were analyzed for multiple parameters. The ability of first versus last urine values to detect the presence of renal damage was compared according to postnatal or fetal autopsy information. RESULTS: Fetuses with minimal renal damage had patterns of decreasing hypertonicity and last urine values below cutoff thresholds indicative of favorable prognosis. Fetuses with significant renal damage had higher initial values and patterns of increasing hypertonicity. For five of six parameters, last urine samples were more predictive of renal damage than first urine samples. CONCLUSION: Last urine values together with pattern-of-change trend analysis after serial vesicocenteses improve diagnostic precision in fetuses with complete obstructive uropathy.

Electrolytes↗

Prenatal cytogenetic abnormalities: correlations of structural rearrangements and ultrasonographically detected fetal anomalies.

OBJECTIVE: Our purpose was to determine the distribution of karyotypic abnormalities detected at prenatal diagnosis, fetal anomalies, and ability for fluorescent in situ hybridization detection. STUDY DESIGN: Our cytogenetic database from January 1988 to April 1994 was categorized according to type and potential detection by current standard fluorescent in situ hybridization probes. Fetal anomalies and cytogenetic aberrations were compared. RESULTS: A total of 664 cases of abnormal fetal karyotypes were identified from 12,454 prenatal cytogenetic cases (7529 amniocenteses and 4925 chorionic villus sampling) and were classified as autosomal aneuploidy (331), sex aneuploidy (103), polyploidy (38), marker aneuploidy (19) and structural rearrangements (173). Standard fluorescent in situ hybridization probes would have missed 31% of the abnormal cases: 90 aneuploidy, 14 de novo marker aneuploidy, and 65 de novo structural aberrant cases. The 134 cases of structural chromosomal rearrangements with complete ultrasonographic records were further classified as polymorphism (42), familial (43), or de novo (49). Frequency of fetal anomaly detection by ultrasonography in de novo cases (22/49) was higher than other rearrangements (chi 2 7.4, p = 0.006). CONCLUSION: The contribution of unusual aneuploidies (16%) and structural chromosomal rearrangements (26%) in prenatal diagnostic practice is significant. Fetal anomalies were detected by ultrasonography in 45% of the de novo rearrangement cases. Fluorescent in situ hybridization would miss 31% of the abnormal cases.

Aneuploidy↗

Combining humerus and femur length for improved ultrasonographic identification of pregnancies at increased risk for trisomy 21.

OBJECTIVE: Our purpose was to evaluate the value of the combination of femur and humerus length measurements in ultrasonographic screening for trisomy 21. STUDY DESIGN: Direct necropsy measurements were analyzed on 703 midgestational fetuses (641 normal, 62 with trisomy 21). The (leg+arm length)/foot length ratio was found to be significantly shortened for fetuses with trisomy 21. On the basis of necropsy data 576 midgestational pregnancies were evaluated ultrasonographically for (femur+humerus length)/foot length ratio to identify fetuses at increased risk for trisomy 21. RESULTS: An ultrasonographic (femur+humerus length)/foot length ratio < or = 1.75 gave a 15.3 odds ratio risk for trisomy 21 in our high-risk population and correctly identified 53% of fetuses with trisomy 21, with a false-positive rate of 7%. In addition, the use of this ratio eliminates the need for gestational age-corrected nomograms and complicated calculations in ultrasonographic screening. CONCLUSION: The (femur+humerus length)/foot length ratio may be an additional effective ultrasonographic marker for identification of fetuses at increased risk for trisomy 21.

Anthropometry↗

Risk of anomalies as a function of level of elevated maternal serum alpha-fetoprotein.

OBJECTIVE: Most neural tube defects risks are not actual but mathematical extrapolations. We sought to evaluate this risk and to compare actual performance. STUDY DESIGN: This was a retrospective study of a referral population with elevated maternal serum alpha-fetoprotein results between 1987 and 1992. Ultrasonography results, delivery records, and autopsy results were compared with entry levels of maternal serum alpha-fetoprotein, and the percentage of fetal anomalies detected in this study was evaluated. RESULTS: A total of 773 patients with elevated maternal serum alpha-fetoprotein levels were evaluated. There was a progressive increase in the incidence of anomalies as a direct function of the level of the maternal serum AFP, varying from 3.4% at a level of 2.5 to 40.3% at a level > 7.0. CONCLUSION: Data from this study support the correlation of maternal serum AFP levels with the risk of neural tube defect and ventral wall defects.

Congenital Abnormalities↗

Fetal compromise associated with extreme fetal bile acidemia and maternal primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis is a rare form of progressive biliary inflammation and fibrosis of unknown etiology that ultimately destroys the liver, leading to cirrhosis, liver failure, and death. Only one prior case has been reported in pregnancy. CASE: Our patient had the diagnosis of primary sclerosing cholangitis made 2 years before conception. Her course was remarkable for retroplacental hemorrhage at 14-16 weeks and preplacental hemorrhage at 28-34 weeks, with fetal growth retardation, spontaneous premature rupture of the membranes, meconium-stained amniotic fluid, fetal bradycardia, and peripartal exacerbations of her disease. Most uniquely, however, in our case the fetal compromise was associated with an extreme elevation of the bile acid level to greater than 2000 mg/dL in the fetal circulation. CONCLUSION: The extreme elevation of fetal bile acidemia at levels greater than 40 times normal in our case may well represent the pathophysiologic link between aberrations of maternal bile acid metabolism during pregnancy and fetal compromise.

Adult↗

Outcome of term gestation neonates whose mothers received intrapartum antibiotics for suspected chorioamnionitis.

Intrapartum antibiotics are commonly given to women suspected of having chorioamnionitis. However, there is no consensus regarding management of their babies. To date, there are no data concerning the clinical courses and outcomes of term gestation, "pretreated" neonates. We performed a retrospective review to assess the clinical courses of such infants. From 1987 to 1989, chorioamnionitis was diagnosed in 123 women, 102 of whom received intrapartum antibiotics. Of the 86 term gestation infants born to women in the latter group, 63 were completely asymptomatic. When compared with these neonates, the 23 symptomatic infants were more likely to have lower median 1 and 5 minute Apgar scores (3 vs 8 and 7 vs 9, respectively; p < 0.0001), higher immature:mature neutrophil ratios on their initial complete blood counts (0.48 vs 0.24; p = 0.0003), and positive urine antigen studies for group B Streptococcus in the presence of negative blood cultures (4 vs 2; p = 0.042). The intrapartum courses of those infants destined to be symptomatic were more likely to be complicated by fetal tachycardia (p = 0.049) and malodorous amniotic fluid (p = 0.005). Since more than 95% of asymptomatic, pretreated, term gestation neonates have a benign clinical course, aggressive evaluation and management of these infants may not be necessary.

Anti-Bacterial Agents↗

Cocaine and development: mechanisms of fetal toxicity and neonatal consequences of prenatal cocaine exposure.

As cocaine use during pregnancy has become increasingly recognized, there also has been increased concern about the toxic and teratogenic properties of cocaine on the fetus. A significant literature exists describing the adverse fetal and neonatal outcomes associated with in utero cocaine exposure. However, specific causality by cocaine on outcome in the human is difficult to ascertain because of multiple confounding variables associated with substance abuse including social factors and polydrug use as well as difficulty in confirming timing, dose and frequency of cocaine exposure. Most literature suggests that prenatal cocaine exposure is associated with developmental risk to the fetus. What is currently unknown is the extent of risk, the additive and/or synergistic factors contributing to cocaine's toxicity and the reversibility of the injury. In this paper we review the pharmacologic properties of cocaine as related to a model of mechanisms for developmental injury secondary to cocaine exposure and the published literature on the adverse fetal and neonatal outcomes associated with cocaine use during pregnancy. Specific attention has been focused on the structural, neurobehavioral and respiratory control teratogenesis.

Animals↗

Fetal umbilical artery Doppler response to graded maternal aerobic exercise and subsequent maternal mean arterial blood pressure: predictive value for pregnancy-induced hypertension.

Predictive tests for the identification of women at high risk of the development of preeclampsia are critical to allow the most appropriate preventive measures. Preeclampsia is a vasospastic condition of pregnancy characterized by early and enhanced vascular reactivity to endogenous pressor agents. Exercise tolerance testing with cycle ergometry to induce hemodynamic response measured with duplex Doppler A/B ratio of the umbilical artery could unmask latent vascular pressor hypersensitivity. Our prospective cohort study was designed to test the efficacy of the American College of Obstetricians and Gynecologists exercise in pregnancy guidelines for the low-risk athletic, physically active, or sedentary patient. The pattern of fetal response to material exercise testing at 28 weeks' gestation was compared with subsequent maternal mean arterial blood pressure and the development of pregnancy-induced hypertension and preeclampsia. Doppler A/B ratio during the recovery period was assessed as below baseline (18) or elevated above resting baseline values (12). Third-trimester blood pressure pattern was assessed to be elevated in 11 patients, 10 of whom had elevated recovery A/B ratios. The Fisher exact test results were (p = 0.00002) positive predictive value, 83%; negative predictive value, 94%; sensitivity, 91%; and specificity, 89%. Preeclampsia developed in four patients; all had elevated recovery A/B ratios. Fisher exact test results were (p = 0.01806) positive predictive value, 33%; negative predictive value, 100%; sensitivity, 100%; and specificity, 69%.

Blood Pressure↗

Maternal cocaine addiction and fetal behavioral state. I: A human model for the study of sudden infant death syndrome.

Abnormalities of respiratory regulation, such as apnea and abnormal hypoxic arousal during sleep, are mechanistic in the pathophysiology of SIDS. In utero cocaine exposure is associated with poor head growth, abnormal neurodevelopment, and an increased incidence of sudden, unexplained death, suggesting that in utero cocaine exposure disrupts the central regulation of breathing. It is likely that this disruption is due to altered CNS maturation. Indeed, cocaine alters norepinephrine metabolism within the locus coeruleus, important in arousal from sleep, suggesting that the increased incidence of SIDS in cocaine exposed infants may be secondary to sleep-related deficits in arousal. Since components of fetal behavioural state organization reflect the successful integration of the Central Nervous System, have a specific developmental timetable, and can be studied by fetal ultrasound techniques, we developed a strategy for assessing the state organization of the fetus by ultrasound techniques. We hypothesize that fetal evaluation of state will be a marker of abnormal CNS maturation and a predictor of risk, i.e. abnormal neurodevelopment and/or state related arousal deficits predisposing the cocaine exposed neonate to SIDS. We propose that the study of in utero cocaine exposed fetuses will provide a human model for examining the pathophysiology of SIDS.

Behavior↗

In utero cocaine exposure: observations of fetal behavioral state may predict neonatal outcome.

Components of fetal behavioral state organization reflect the successful integration of the central nervous system, have a specific developmental timetable, and can be studied with fetal ultrasonographic techniques. To test the hypothesis that evaluation of state organization is a marker of abnormal central nervous system maturation and a predictor of risk, we studied 20 fetuses and newborns exposed to cocaine in utero. Fetal assessments were accomplished by serial ultrasonographic examination, videotaped, and scored by a scheme developed by the authors to assess organization and regulation of behavioral states. Newborn neurobehavioral assessments also emphasized organization and regulation of behavioral state. Abnormal or delayed state behavior was identified in 13 of 20 fetuses. State organization was evaluated as suspect or abnormal for 16 of the 20 exposed newborns. Disorganized behavioral state in the fetus successfully predicted abnormal newborn behavior. These findings support the concepts that cocaine exposure disrupts central nervous system development and that fetal assessment of state is predictive of neonatal outcome.

Child Behavior↗