Rapid determination of zygosity and common aneuploidies from amniotic fluid cells using quantitative fluorescent polymerase chain reaction following genetic amniocentesis in multiple pregnancies.
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Following second-trimester twin amniocentesis, we used quantitative fluorescent polymerase chain reaction (QF-PCR) assays and polymorphic small tandem repeats (STR) for rapid determination of zygosity and common aneuploidies from amniotic fluid (AF) cells in four pregnancies with like-sex twins, fused placentae and inconclusive chorionicity. The first and the second cases were suspected to have inadvertent sampling of the same amniotic cavity twice. The first case showed a dizygotic (DZ) pattern and repeat amniocentesis was thus avoided. The second case was monozygotic (MZ) and was complicated by discordant fetal growth and twin-twin transfusion syndrome. The third case was associated with a co-twin malformation, occipital encephalocele. DNA studies revealed MZ twinning with a discordant structural defect. The fourth case was associated with co-twin abnormalities of cystic hygroma and hydrops fetalis. DNA studies showed DZ twinning with discordant structural and chromosomal defects. The QF-PCR assay with STR has the advantages of rapid determination of zygosity and common aneuploidies in AF cells. This simple test appears to be useful in the instances of possible inadvertent puncture of the same amniotic cavity twice during amniocentesis and of discordant fetal structural and/or chromosomal abnormalities following genetic amniocentesis in multiple pregnancies with uncertain chorionicity. (+info)
Incidence of congenital malformations in children born after ICSI.
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The aim of this study was to determine the incidence of congenital malformations in a complete cohort of children born after intracytoplasmic sperm injection (ICSI). The medical records were retrieved for 1139 infants, 736 singletons, 200 sets of twins and one set of triplets. The total number of infants with an identified anomaly was 87 (7.6%), 40 of which were minor. The incidence of malformations in children born after ICSI was also compared with all births in Sweden using data from the Swedish Medical Birth Registry and the Registry of Congenital Malformations. For ICSI children, the odds ratio (OR) for having any major or minor malformation was 1.75 [95% confidence interval (CI) 1.19-2.58] after stratification for delivery hospital, year of birth and maternal age. If stratification for singletons/twins was also done, the OR was reduced to 1.19 (95% CI 0.79-1.81). The increased rate of congenital malformations is thus mainly a result of a high rate of multiple births. The only specific malformation which was found to occur in excess in children born after ICSI was hypospadias (relative risk 3.0, exact 95% CI 1. 09-6.50) which may be related to paternal subfertility. (+info)
Congenital malformations after intracytoplasmic injection of spermatids.
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Spermatid microinjection into oocytes was applied in cases of intracytoplasmic sperm injection (ICSI)/testicular sperm extraction (TESE) where no spermatozoa could be found in numerous testicular samples. Although several pregnancies were obtained with this procedure, serious concerns remain regarding its safety. Although the relevance of the injection of spermatids is by no means certain, we wish to report that from four pregnancies obtained after injection of elongated spermatids, two cases of major malformation resulted. (+info)
Congenital anomalies in Glasgow between 1982 and 1989 and chromium waste.
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BACKGROUND: The former site of a factory in Glasgow and nearby areas were found to be heavily polluted by chromium waste. This gave rise to local concern on possible health effects. As part of a wider study answering this concern, congenital malformations were investigated. METHODS: A descriptive geographical study was carried out. A 10 km circle centred on the factory site was designated as the study area and subdivided into one circle of 2 km radius and eight 1 km wide rings. Significant differences in relative risk between the circle and rings and a decreasing trend of risk with distance from the centre would point towards a teratogenic role of the chromium waste. Relative risks by rings were obtained by Poisson regression. Relative risks by deprivation categories were also obtained, with most results adjusted by these categories. RESULTS: Significant differences in risk appeared, with the area containing the polluted soil having the lowest risk. Aggregations of rings showed a central area with a relatively low risk, followed by an intermediate one with the highest risk and an external area with risk also high. Relative risk appeared to increase sharply between the most affluent category and the rest, then growing steadily with increasing deprivation but decreasing slightly for the most deprived. CONCLUSIONS: Relative risk shows a significant peak in an area 2-4 km away from the pollutant, which does not point towards a possible teratogenic effect of the chromium waste. Relative risk of congenital malformations for the more affluent sector of the population appeared to be markedly lower than that for the rest. (+info)
Trigeminal neuralgia associated with tentorial agenesis and temporal lobe herniation--case report.
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A 22-year-old female presented with an extremely rare case of trigeminal neuralgia associated with tentorial agenesis. The pulsating pain in her left maxillary region persisted for an abnormally long time and had no trigger zone. The pain later spread to the periorbital region. Coronal magnetic resonance imaging revealed left medial temporal lobe herniation caused by tentorial agenesis. The herniated temporal lobe, which had distorted the superior cerebellar artery, was causing compression of the trigeminal nerve. Her condition improved following microvascular decompression surgery. Tentorial agenesis should be considered as a cause of atypical pulsating facial pain, especially in younger patients. (+info)
5,10-Methylenetetrahydrofolate reductase gene variants and congenital anomalies: a HuGE review.
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The enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) is involved in folate metabolism. The MTHFR gene is located on chromosome 1 (1p36.3), and two common alleles, the C677T (thermolabile) allele and the A1298C allele, have been described. The population frequency of C677T homozygosity ranges from 1% or less among Blacks from Africa and the United States to 20% or more among Italians and US Hispanics. C677T homozygosity in infants is associated with a moderately increased risk for spina bifida (pooled odds ratio = 1.8; 95% confidence interval: 1.4, 2.2). Maternal C677T homozygosity also appears to be a moderate risk factor (pooled odds ratio = 2.0; 95% confidence interval: 1.5, 2.8). The A 1298C allele combined with the C677T allele also could be associated with an increased risk for spina bifida. Some data suggest that the risk for spina bifida associated with C677T homozygosity may depend on nutritional status (e.g., blood folate levels, intake of vitamins) or on the genotype of other folate-related genes (e.g., cystathionine-beta-synthase and methionine synthase reductase). Studies of the C677T allele in relation to oral clefts, Down syndrome, and fetal anticonvulsant syndrome either have yielded conflicting results or have not been yet replicated. (+info)
Bias associated with study protocols in epidemiologic studies of disease familial aggregation.
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The effect of selection bias has not been well evaluated in epidemiologic studies which focus on familial aggregation. The authors illustrate this type of bias for a reconstructed cohort study. With the reconstructed cohort design, cases and controls are first selected from the population and their relatives form the exposed and unexposed cohorts, respectively. The recurrence risk ratio (RRR) is calculated to assess and measure familial aggregation. The ways of utilizing information from relatives affects the estimate of RRR, and the authors show that a traditional method used in epidemiologic studies can yield a severely biased estimate of the RRR. However, this traditional approach can give approximately unbiased estimates under special conditions. A novel selection approach is proposed which yields an unbiased estimate of RRR. In conclusion, when relatives are identified through cases or controls, they should be included and counted in the study cohorts each time a case or control is selected, even if they or other family members have already been included. (+info)
Socioeconomic inequalities in risk of congenital anomaly.
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AIMS: To investigate socioeconomic inequalities in the risk of congenital anomalies, focusing on risk of specific anomaly subgroups. METHODS: A total of 858 cases of congenital anomaly and 1764 non-malformed control births were collected between 1986 and 1993 from four UK congenital malformation registers, for the purposes of a European multicentre case control study on congenital anomaly risk near hazardous waste landfill sites. As a measure of socioeconomic status, cases and controls were given a value for the area level Carstairs deprivation index, by linking the postcode of residence at birth to census enumeration districts (areas of approximately 150 households). RESULTS: Risk of non-chromosomal anomalies increased with increasing socioeconomic deprivation. The risk in the most deprived quintile of the deprivation index was 40% higher than in the most affluent quintile. Some malformation subgroups also showed increasing risk with increasing deprivation: all cardiac defects, malformations of the cardiac septa, malformations of the digestive system, and multiple malformations. No evidence for socioeconomic variation was found for other non-chromosomal malformation groups, including neural tube defects and oral clefts. A decreasing risk with increasing deprivation found for all chromosomal malformations and Down's syndrome in unadjusted analyses, occurred mainly as a result of differences in the maternal age distribution between social classes. CONCLUSION: Our data, although based on limited numbers of cases and geographical coverage, suggest that more deprived populations have a higher risk of congenital anomalies of non-chromosomal origin and some specific anomalies. Larger studies are needed to confirm these findings and to explore their aetiological implications. (+info)