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Aneuploidy Screening (aneuploidy + screening)
Selected AbstractsImproved prenatal aneuploidy screening using the novel advanced first-trimester screening algorithm: A multicenter study of 10,017 pregnanciesJOURNAL OF CLINICAL ULTRASOUND, Issue 7 2008Peter Schmidt MD Abstract Purpose. It has been postulated that the maternal age component should be completely excluded from first-trimester screening (FTS) for fetal aneuploidies. In this study, we tested a new algorithm known as advanced first-trimester screening (AFS), which disregards maternal age. Method. In a multicenter study, FTS findings were retrieved from 10,017 pregnancies. FTS risk assessment was performed using the Nicolaides method, and the AFS score was calculated. The results of both methods were compared. Results. Within this population, 81 fetuses had an abnormal karyotype. The sensitivity of the 2 algorithms was 86.4%. When the AFS method was used, the positive predictive value rose from 9.6% (FTS) to 12.4% (AFS). Using AFS, the test positive rate could be decreased by 161 cases (,22.2%) (p < 0.0001), due to a reduction of false positive cases. As a result, the false positive rate of AFS was 24.5% lower than that of FTS, while the same number of aneuploidies was detected. Conclusion. AFS can markedly reduce the rate of false positive test results. If these results are confirmed by larger multicenter studies, the new AFS will represent a great improvement in fetal aneuploidy screening. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008 [source] New frontiers of assisted reproductive technology (Chien Tien Hsu Memorial Lecture 2007)JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 1 2009P. C. Ho Abstract Many significant advances have been made in assisted reproductive technology since the birth of the first baby conceived with in vitro fertilization and embryo transfer. The development of recombinant gonadotropins and gonadotropin releasing hormone antagonists helps to simplify the ovarian stimulation. Excessive ovarian stimulation should be avoided because of the risks of ovarian hyperstimulation syndrome and reduction in endometrial receptivity. Maturation of oocytes in vitro has been developed in some centers. It is still uncertain whether techniques such as assisted hatching, blastocyst transfer and pre-implantation aneuploidy screening can improve the live birth rates in assisted reproduction. The introduction of pre-implantation genetic diagnosis for selection of human lymphocyte antigens (HLA) compatible embryos for treatment of siblings has raised ethical concerns. There is a higher risk of obstetric complications and congenital abnormalities even in singleton pregnancies achieved with assisted reproduction. Because of the risks of multiple pregnancies, elective single embryo transfer is increasingly used in good-prognosis patients. With a good freezing program, the cumulative pregnancy rate (including the pregnancies from subsequent replacement of frozen-thawed embryos) is not adversely affected. Improvement in cryopreservation techniques has made it possible to cryopreserve slices of ovarian tissue or oocytes, thus helping women who have to receive sterilizing forms of anti-cancer treatment to preserve their fertility. It is important that the development of the new techniques should be based on good scientific evidence. Ethical, legal and social implications should also be considered before the introduction of new techniques. [source] Ultrasound screening for fetal aneuploidy using soft markers in the overweight and obese gravida,PRENATAL DIAGNOSIS, Issue 9 2010Lily J. Tsai Abstract Objective To determine the completion rate of ultrasound surveys for aneuploidy markers by maternal body mass index (BMI). Methods A retrospective review of ultrasounds on midtrimester singleton pregnancies was performed. Subjects were grouped as normal, overweight (BMI 25,29.9 kg/m2), and obese: class I (30,34.9 kg/m2), class II (35,39.9 kg/m2), and class III (, 40 kg/m2). Examinations with visualization of at least seven of eight markers were considered complete. Results Of 14 353 ultrasounds reviewed, 5690 patients were eligible: 43% normal, 29% overweight, 27% obese. Completion rates differed significantly between groups (64% normal, 64% overweight, 61% class I, 55% class II, 47% class III, p < 0.001). The screen positive rates (,1 marker) differed significantly overall (16% normal, 13% overweight, 15% class I, 12% class II, 10% class III, p < 0.02), but not for complete examinations (p = 0.42). Conclusions Since completion rates for ultrasound aneuploidy screening are inversely related to maternal obesity, obese women are underscreened. Copyright © 2010 John Wiley & Sons, Ltd. [source] Issues and concerns of couples presenting for preimplantation genetic diagnosis (PGD)PRENATAL DIAGNOSIS, Issue 12 2002Mandy G. Katz Abstract Background The use of preimplantation genetic diagnosis (PGD) to select genetically ,normal' human embryos and to transfer them to the uterus of a woman has generated considerable controversy. Debate has occurred over the implications of PGD, sex selection, safety of embryonic manipulation and eugenics. This study evaluates a range of social and moral concerns of couples towards PGD and assisted reproductive technologies (ART) prior to treatment to obtain unbiased authentic attitudes independent of the treatment cycle and the outcome. Methods A total of 121 subjects were administered a structured questionnaire after each couple's in vitro fertilization (IVF) or genetic counselling session. Group A consisted of 41 subjects presenting for PGD of single gene disorders (PGD-SG) and group B consisted of 48 subjects undertaking PGD for aneuploidy screening (PGD-AS). A control group consisted of 32 subjects that were about to commence their first IVF cycle. Results and discussion All groups found PGD to be a highly acceptable treatment. They expressed little concern about its extension to testing non-disease states such as sex and they were strongly in favour of a shared decision-making model in which couples have considerable autonomy over decisions about the embryo(s) to transfer. Differences between the groups included issues surrounding the transfer of embryos, restrictions to PGD and the destruction of embryos. Copyright © 2002 John Wiley & Sons, Ltd. [source] Preimplantation genetic diagnosis of pericentric inversionsPRENATAL DIAGNOSIS, Issue 9 2001Tomás Escudero Abstract Inversions are structural chromosome abnormalities that may be associated with infertility, multiple miscarriage and chromosomally unbalanced offspring. Preimplantation genetic diagnosis (PGD) with subtelomeric probes was used to select for transfer only those embryos that were normal or balanced for three pericentric inversions. In contrast to previous protocols the present procedure allows the detection of unbalanced embryos that might arise from U-recombination in the inverted region. Additionally, aneuploidy screening was carried out in two cases by a second round of fluorescent in situ hybridization (FISH) with centromeric probes. Of the three couples that underwent the procedure one became pregnant twice. The first pregnancy delivered a healthy and chromosomally normal baby and the second pregnancy is ongoing with triplets. Copyright © 2001 John Wiley & Sons, Ltd. [source] The selective use of rapid aneuploidy screening in prenatal diagnosisAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 1 2009Jan E. DICKINSON Aims: To evaluate the diagnostic utility and costing of the selective use of rapid aneuploidy screening (RAS) for chorion villus sampling (CVS) and amniocentesis specimens. Methods: CVS and amniocenteses performed between 2000 and 2006 were identified. Cases were subdivided into two groups: (i) RAS in addition to long-term culture and (ii) long-term chromosome culture alone. The frequency of RAS, the proportion of abnormal results and the cytogenetic costings were reviewed. Results: A total of 3315 procedures were performed: 730 CVS and 2585 amniocenteses. An abnormal karyotype culture was present in 366 of 3315 (11%). For CVS an abnormal culture was present in 164 (22.5%). RAS (short-term culture/direct preparation) was selectively used in 399 cases (54.6%) with an abnormal result in 128 (32% of RAS). For amniocentesis, 206 chromosome abnormalities were present (8.0% of specimens). RAS (interphase FISH) was selectively used in 580 amniocenteses (22.4%). FISH was requested in 95 (66.4%) of the 143 abnormal cases potentially detectable with standard probes. There was a progressive increase in utilisation of RAS for amniocentesis (8.9% in 2000 to 43.3% of cases in 2006, P < 0.001). CVS RAS was stable. This liberalisation resulted in a fourfold increase in expenditure for FISH and cost/abnormality detected ($A970 per abnormal result in 2000 to $A4015 per abnormal result in 2006). Conclusion: The selective use of prenatal RAS results in a reasonably high detection rate for chromosomal anomalies. Liberalisation of RAS, however, is an expensive cytogenetic model. An approach based on some predictive level of risk combined with resource funding levels may be a more pragmatic approach. [source] | ||||||||||