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M J Mahoney

Publications and source records attributed to M J Mahoney.

At least 55 records · Page 3Linked to original sources
PubMed1995

Invasive techniques for prenatal diagnosis: current concepts.

Recent dramatic advances have been made in our understanding of the genetic basis of diseases. One result will be an increase in the number of pregnant women considered potential candidates for prenatal diagnosis. At the same time, the invasive techniques by which fetal specimens for prenatal diagnosis are obtained have come under increasing scrutiny in the lay press. Practicing obstetricians must have sufficient knowledge of the benefits, risks, and limitations of these techniques to respond to patient inquiries. This article reviews the commonly used invasive prenatal diagnostic methods, including amniocentesis, chorionic villus sampling, and fetal blood sampling, as well as less widely available techniques, such as fetal skin and liver biopsies. Such relevant issues as indications, timing, and fetal risks are covered.

Amniocentesis↗
PubMed1994

Hyperechoic fetal bowel: the perinatal consequences.

A number of publications have reported an association between the finding of hyperechoic fetal bowel on prenatal sonogram and disorders such as aneuploidy and cystic fibrosis. To define more precisely the significance of this finding, we systematically reviewed the published material on the subject. Based on a total of 357 reported cases, we documented a high prevalence of cystic fibrosis (25.6 per cent) and chromosome abnormality (12.4 per cent) associated with increased bowel echogenicity in the fetus. High rates of intrauterine growth retardation (14.9 per cent), fetal demise (9.0 per cent), and prematurity (15.3 per cent) were also found. The data were obtained from a population at high a priori risk for aneuploidy and included fetuses at 1 in 4 risk for cystic fibrosis reported in two studies. This increased the bias towards an adverse outcome. The rate of complications when a hyperechoic abdomen is noted in a low-risk fetal population has so far not been delineated. Although the high frequency of complications found is of concern and warrants investigation, extrapolation of these risk figures to a fetal population at low a priori risk may not be appropriate.

Abdomen↗
PubMed1994

The use of averaged electrode voltages to assess the function of nucleus internal cochlear implant devices in children.

Averaged electrode voltages (AEVs) provide an objective measure of the output of the Nucleus multichannel cochlear implant device. AEVs are the peak-to-peak voltages of each electrode in the internal array and are recorded from electrodes placed on the scalp. This article summarizes average voltage data for 25 children with complete insertions of the electrode array. Data are compared with previously published adult data and are evaluated based on the location of the recordings (clinic versus operating room). AEV data can be applied clinically to identify implant problems. AEV recordings for this purpose are particularly important with children who may not be able to provide accurate reports of implant function. Case studies are presented to illustrate the application of the AEV procedure to examine implant malfunction in six children.

Adolescent↗
PubMed1994

Unusual inheritance of primary ciliary dyskinesia (Kartagener's syndrome).

Primary ciliary dyskinesia syndrome is characterised by chronic sinusitis, bronchiectasis, and, in 50% of cases, dextrocardia. It is generally believed to be inherited as an autosomal recessive disorder. In this report, we describe a family consisting of a mother and her five male children, the offspring of three different fathers, all of whom have this syndrome. This argues for either an X linked or autosomal dominant pattern of inheritance. Cytogenetic and FISH (fluorescent in situ hybridisation) analyses were done on the mother and one son and were found to be normal.

Adolescent↗
PubMed1993

Fetal blood sampling and cytogenetic abnormalities.

From September 1984 to April 1991, we performed cytogenetic analysis on fetal blood samples from 214 second- and third-trimester pregnancies. One hundred and thirty-four cases were referred to consider the possibility of chromosomal mosaicism following amniocyte studies. The confirmation rate of mosaicism is at 0 per cent (0/9), 1.4 per cent (1/70), and 40 per cent (22/55) for cases of level I, level II, and level III mosaicism, respectively. Four out of 17 cases were positive for the diagnosis of fragile X syndrome. Of 63 cases with abnormal ultrasound findings, blood disorders, or other genetically related clinical conditions, 11 were found to have a chromosome abnormality. Fetal blood sampling is a valuable adjunct to other methods in the prenatal diagnosis of chromosomal mosaicism or pseudomosaicism. It is also useful when rapid cytogenetic diagnosis is desired because of malformations detected in pregnancies at a late gestational age.

Cells, Cultured↗
PubMed1993

Follow-up of pregnancies complicated by placental mosaicism diagnosed by chorionic villus sampling.

Thirty-nine (2.3 per cent) of 1724 chromosome studies from diagnostic chorionic villus samplings (CVS) done between 1983 and 1990 showed either level III (true) mosaicism (1.2 per cent) or level II (pseudo-) mosaicism (1.1 per cent) for chromosomal aneuploidy. Follow-up information on these 39 pregnancies was collected from questionnaires to families, paediatricians, and obstetricians. For all cases in which the pregnancy was continued and further testing was accomplished, the mosaicism was felt to be confined to the placenta. As compared with a control group of pregnancies evaluated by CVS with normal karyotypes, there was no increased incidence of pregnancy loss, congenital malformations, or developmental delay in the infants. Although intrauterine growth retardation occurred in several of the level III mosaic cases, adequate catch-up growth has been demonstrated.

Abortion, Spontaneous↗
PubMed1993

First-trimester prenatal diagnosis of osteogenesis imperfecta type II by DNA analysis and sonography.

Osteogenesis imperfecta type II was diagnosed prenatally by analysis of DNA obtained from chorionic villus sampling (CVS) performed at 12 weeks of gestation in a woman who previously had had an affected child. The father had been shown to be mosaic for a mutation in the gene (COL1A2) which encodes the alpha 2(I) chain of type I collagen. An affected fetus was predicted by detection of the mutation in amplified chorionic villus genomic DNA. Ultrasound examination at 13 weeks 4 days demonstrated femoral deformity and virtual absence of calvarial mineralization. In pregnancies at risk for osteogenesis imperfecta type II, sonographic evidence of skeletal abnormalities may be evident by 13 weeks' gestation.

Adult↗
PubMed1993

Transabdominal thin-gauge embryofetoscopy: a technique for early prenatal diagnosis and its use in the diagnosis of a case of Meckel-Gruber syndrome.

OBJECTIVE: Our aim was to develop and evaluate a transabdominal endoscopic technique to visualize the embryo or fetus with thin-gauge needles and submillimetric fiberoptic endoscopes. METHODS: Under ultrasonographic guidance, an 18- or 19-gauge thin-wall needle was introduced into the uterus of 28 patients undergoing first-trimester or early second-trimester termination of pregnancy. A 0.7 mm endoscope was threaded through the lumen of the needle after removal of the stylet. Visualization of the embryo-fetus was attempted before 14 weeks' gestation (n = 20). From 16 to 20 weeks (n = 8), the needle and endoscope were directed to the placental insertion of the umbilical cord, and a cordocentesis was performed. RESULTS: Excellent visualization of the surface anatomy of fetuses from 7 to 13 weeks was obtained in 85% of cases (17/20). A diagnosis of Meckel-Gruber syndrome was made at 11 weeks' menstrual age by visualizing postaxial polydactyly and an occipital encephalocele. Endoscopically assisted cordocentesis allowed visualization of the lumen of the umbilical vein and of the blood flow within it. CONCLUSION: Endoscopic visualization of the embryo or fetus can be performed transabdominally in the first trimester with small-delivered endoscopes. This represents a clear advantage over previous endoscopic approaches to the human pregnancy. Potential applications of this technique include a precise description of fetal anatomy and physiologic features, diagnosis of anomalies, and therapeutic fetal interventions.

Abdomen↗
PubMed1993

Embryoscopic demonstration of hemorrhagic lesions on the human embryo after placental trauma.

OBJECTIVE: The purpose of this study was to evaluate embryoscopically the effect of placental trauma on the human embryo. STUDY DESIGN: Patients undergoing elective first-trimester termination of pregnancy underwent transcervical embryoscopy both before and after chorionic villus sampling. If hemorrhagic lesions were not observed on the fetus after chorionic villus sampling, partial placental detachment was performed with a blunt instrument, and the fetus was again observed. RESULTS: Hemorrhagic lesions were observed in 20 of 43 fetuses. In 13 of them, the lesions occurred after placental trauma with the chorionic villus sampling catheter alone (30%), whereas lesions were observed in the remaining seven patients after additional blunt placental disruption. The lesions were located most frequently on the cephalic region, and they grew in size during the observation period. Gestational age or amount of chorionic villus sampling tissue was not different between fetuses with or without lesions. CONCLUSION: Placental trauma results in embryoscopically demonstrable hemorrhagic lesions on the human embryo. Whereas some of these lesions may be of no consequence, others may lead to permanent changes. If similar lesions occur in deeper tissues, they could cause disruptions in development and conceivably could be related to anomalies reported in infants born to women who have had chorionic villus sampling procedures. Embryoscopy affords the opportunity to study possible mechanisms involved in the occurrence of anomalies.

Cervix Uteri↗
PubMed1993

Introduction to special section: theoretical developments in the cognitive psychotherapies.

The cognitive psychotherapies have developed and substantially differentiated since their inception in the 1950s. Six major themes in their theoretical development are discussed: (a) the differentiation of rationalist and constructivist therapies and metatheories of knowing; (b) the acknowledgement of social, biological, and embodiment processes in therapy; (c) the recognition of unconscious processes; (d) an increasing focus on self-organizing and self-protective processes in life span personality development, with such processes being embedded in interpersonal and social system dynamics; (e) a shift toward different views of emotionality and the incorporation of experiential techniques; and (f) a synergistic involvement in the psychotherapy integration movement. The cognitive psychotherapies reflect remarkable activity, a point illustrated and elaborated in the articles that constitute this special section.

Adaptation, Psychological↗
PubMed1992

A randomized comparison of transcervical and transabdominal chorionic-villus sampling. The U.S. National Institute of Child Health and Human Development Chorionic-Villus Sampling and Amniocentesis Study Group.

BACKGROUND: Chorionic-villus sampling is done in early pregnancy to obtain fetal cells for the prenatal diagnosis of genetic and chromosomal defects. Transcervical chorionic-villus sampling has been shown to be safe and effective in national trials. Recently, an alternative transabdominal technique has been suggested as potentially easier and safer. METHODS: From April 1987 through September 1989, we prospectively compared transcervical and transabdominal chorionic-villus sampling in 3999 women with singleton pregnancies in whom the risk of a genetically abnormal fetus was increased. Women between 7 and 12 weeks of gestation underwent ultrasonographic evaluation of placental and uterine position. Those with active vaginal infections, active bleeding, or cervical polyps were excluded. If the obstetrician thought either sampling procedure was acceptable, the woman was asked to consent to random assignment to one of the two procedures. Both groups were followed to determine the outcome of pregnancy and the rate of spontaneous fetal loss after chorionic-villus sampling. RESULTS: Among the 3999 women who entered the study, sampling was attempted in 3873 (97 percent), 1944 of whom had been assigned to undergo transcervical sampling and 1929 to undergo transabdominal sampling. Of these 3873 women, sampling was eventually successful in 3863. Sampling was successful after a single insertion of the sampling instrument in 94 percent of the transabdominal procedures and 90 percent of the transcervical procedures. Among the women with cytogenetically normal pregnancies who had sampling because of maternal age, the rate of spontaneous fetal loss through 28 weeks of pregnancy was 2.5 percent in the transcervical-sampling group and 2.3 percent in the transabdominal-sampling group (difference, 0.26 percent; 95 percent confidence interval, -0.5 to 1.0 percent). CONCLUSIONS: Transabdominal and transcervical chorionic-villus sampling appear to be equally safe procedures for first-trimester diagnosis of fetal abnormalities.

Abdomen↗
PubMed1992

Postnatal placental confirmation of trisomy 2 and trisomy 16 detected at chorionic villus sampling: a possible association with intrauterine growth retardation and elevated maternal serum alpha-fetoprotein.

Detection of trisomy 2 and trisomy 16 mosaicism through chorionic villus sampling (CVS) is not an infrequent finding. We describe here two cases, one of non-mosaic trisomy 2 and the other of high level mosaicism for trisomy 16. Amniocentesis in both cases demonstrated non-mosaic 46,XY karyotypes. Each pregnancy continued to delivery of liveborn, normal-appearing boys; both pregnancies were complicated by severe intrauterine growth retardation (IUGR). Postnatal studies of placental biopsies in both cases confirmed the original CVS findings, whereas cord blood karyotypes were normal in both boys. Both children have demonstrated adequate catch-up growth.

Adult↗
PubMed1992

Cytogenetic results from the U.S. Collaborative Study on CVS.

Cytogenetic data are presented for 11,473 chorionic villus sampling (CVS) procedures from nine centres in the U.S. NICHD collaborative study. A successful cytogenetic diagnosis was obtained in 99.7 per cent of cases, with data obtained from the direct method only (26 per cent), culture method only (42 per cent), or a combination of both (32 per cent). A total of 1.1 per cent of patients had a second CVS or amniocentesis procedure for reasons related to the cytogenetic diagnostic procedure, including laboratory failures (27 cases), maternal cell contamination (4 cases), or mosaic or ambiguous cytogenetic results (98 cases). There were no diagnostic errors involving trisomies for chromosomes 21, 18, and 13. For sex chromosome aneuploidies, one patient terminated her pregnancy on the basis of non-mosaic 47,XXX in the direct method prior to the availability of results from cultured cells. Subsequent analysis of the CVS cultures and fetal tissues showed only normal female cells. Other false-positive predictions involving non-mosaic aneuploidies (n = 13) were observed in the direct or culture method, but these cases involved rare aneuploidies: four cases of tetraploidy, two cases of trisomy 7, and one case each of trisomies 3, 8, 11, 15, 16, 20, and 22. This indicates that rare aneuploidies observed in the direct or culture method should be subjected to follow-up by amniocentesis. Two cases of unbalanced structural abnormalities detected in the direct method were not confirmed in cultured CVS or amniotic fluid. In addition, one structural rearrangement was misinterpreted as unbalanced from the direct method, leading to pregnancy termination prior to results from cultured cells showing a balanced, inherited translocation. False-negative results (n = 8) were observed only in the direct method, including one non-mosaic fetal abnormality (trisomy 18) detected by the culture method and seven cases of fetal mosaicism (all detected by the culture method). Mosaicism was observed in 0.8 per cent of all cases, while pseudomosaicism (including single trisomic cells) was observed in 1.6 per cent of cases. Mosaicism was observed with equal frequency in the direct and culture methods, but was confirmed as fetal mosaicism more often in cases from the culture method (24 per cent) than in cases from the direct method (10 per cent). The overall rate of maternal cell contamination was 1.8 per cent for the culture method, but there was only one case of incorrect sex prediction due to complete maternal cell contamination which resulted in the birth of a normal male.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

First-trimester biochemical and molecular diagnoses using chorionic villi: high accuracy in the U.S. collaborative study.

The accuracy of biochemical and molecular prenatal diagnoses using chorionic villi as the fetal source was assessed by seven centres participating in the NICHD collaborative study on the safety and accuracy of chorionic villus sampling (CVS) and amniocentesis. Of 601 pregnancies studied, biochemical methods were used to determine the diagnosis in 283 fetuses at risk for 35 different metabolic disorders. Fifteen different lysosomal storage diseases accounted for 81 per cent of the biochemical prenatal diagnoses performed, with 57 per cent of these pregnancies at risk for Tay-Sachs disease. No errors were made in the biochemical diagnoses that predicted affected or unaffected fetuses. However, the diagnoses of certain disorders (e.g., mucopolysacchariodosis type IH, metachromatic leukodystrophy, and Krabbe disease) occasionally required confirmatory studies in cultured amniocytes because the enzyme results were inconclusive in direct and/or cultured villi or due to the presence of a pseudodeficiency allele. Of these, only the diagnosis of a fetus at risk for Krabbe disease remained inconclusive after special studies to discriminate between mutant and pseudo-deficiency alleles. Recombinant DNA techniques were used to predict the diagnosis of 318 fetuses at risk for 16 different disorders in which the defective disease gene could be detected either directly or by linkage analysis to a nearby polymorphic marker. Of these, 32 per cent were for haemoglobinopathies, 25 per cent for cystic fibrosis, 24 per cent for Duchenne or Becker muscular dystrophy, and 7 per cent for haemophilias. Pregnancies at risk for known disorders with specific molecular lesions (e.g., sickle cell disease) were accurately diagnosed in direct and/or cultured villi. Diagnoses requiring analyses with closely linked polymorphic markers were occasionally uniformative or inconclusive. Maternal contamination was not reported in any biochemical or molecular-based diagnosis. These studies document the high accuracy and rapidity of both biochemical and mutation-specific prenatal diagnoses with direct and cultured chorionic villi.

Adult↗
PubMed1992

Risk factors associated with transcervical CVS losses.

Factors found to be associated with pregnancy loss after transcervical CVS were race (higher for non-white), history of spontaneous abortion, unplanned pregnancy, history of spotting or bleeding during the pregnancy prior to CVS, and placental position (higher for fundal or lateral locations). Whether the increase in loss risk is due to the factor, per se, or the factor plus the CVS cannot be determined due to the lack of appropriate control data.

Adult↗
PubMed1992

Trisomy 5 mosaicism detected prenatally with an affected liveborn.

This paper reports a case of chromosomal mosaicism for trisomy 5 recovered from amniotic fluid cells and from skin fibroblasts of a liveborn dysmorphic male. Routine amniocentesis was performed at 16 weeks' gestation because of parental concern. Trisomy 5 cells were measured from 25 per cent of amniocytes from two culture vessels. No further invasive testing was performed until 32 weeks' gestation, at which time ultrasound examination showed a fetus with intrauterine growth retardation. Fetal blood sampling was then performed, with only karyotypically normal cells recovered. At birth, the child was found to have multiple dysmorphic features and congenital anomalies, including an eventration of the diaphragm and ventricular septal defect, both of which required surgical correction. Chromosomal analysis of cord blood lymphocytes indicated 46,XY; however, 20 per cent of the cultured fibroblasts obtained from the chest skin at the incision site for diaphragmatic repair had a 47,XY, +5 karyotype. Trisomy 5 mosaicism may be another example of tissue-limited mosaicism. Fetal blood sampling can then be falsely reassuring. Furthermore, because some cell lines rarely appear in lymphocyte populations, cytogenetic analysis of multiple tissues is warranted as part of the evaluation of individuals with developmental delay and dysmorphic features.

Abnormalities, Multiple↗
PubMed1992

Fetal humeral length to detect Down syndrome.

OBJECTIVE: Our aim was to evaluate the utility of ultrasonographic humeral length measurements for detection of fetuses with Down syndrome in the midtrimester of gestation. STUDY DESIGN: Ultrasonographic biometry data obtained before genetic amniocenteses on 43 fetuses with Down syndrome and 204 randomly chosen normal fetuses were analyzed. Regression equations relating biparietal diameter to humeral length and femoral length were used to calculate ratios of observed-to-expected length and sensitivity and specificity at various cutoff points. RESULTS: Humeral length in Down syndrome fetuses was significantly shorter than in normal controls (p less than 0.001). A ratio of 0.90 for observed/expected humeral length yielded a sensitivity of 28%, a specificity of 91%, and positive predictive values of 1.23% and 0.41% in populations at risk for Down syndrome of 1 in 250 and 1 in 750, respectively. The equivalent ratio for femoral length yielded a sensitivity of 19%, a specificity of 91%, and positive predictive values of 0.87% and 0.28% for baseline risks of 1 in 250 and 1 in 750, respectively. CONCLUSIONS: The sensitivity of fetal humeral length measurements for Down syndrome detection in our hands was remarkably lower than previously reported. Independence of this parameter from currently used serum screening markers has not been established; therefore implementation in screening programs is not advisable at this point.

Down Syndrome↗