Global qualitative review of images from one sonographer may be preferable to assessment of individual aspects of images. Results from global qualitative review correspond well with findings from quantitative analysis, indicating that the latter can be applied for ongoing audit. Observation of divergent results should prompt extensive personal feedback, rather than a written report, to prevent sonographers from settling in their own, inappropriate technique.
In women who are heterozygous for a genetic disease, genetic analysis of the first polar body allows the identification of oocytes that contain the maternal unaffected gene. These oocytes can be fertilized and transferred to the mother without risk of establishing a pregnancy with a genetically abnormal embryo. We have demonstrated that removal of the first polar body has no effect on subsequent fertilization rates or embryonic growth to the blastocyst stage. We have developed a PCR technique to successfully analyze the PI type Z and PI type M genotypes of alpha-1-antitrypsin deficiency and applied this technique for a couple at risk for PI type ZZ alpha-1-antitrypsin deficiency. After standard IVF treatment to stimulate multiple follicle development, eight oocytes were aspirated transvaginally. Polar bodies were removed by micromanipulation from seven oocytes and fertilization occurred in six cases. PCR analysis was successful in five oocytes. One was PI type M, two were PI type Z and two were heterozygous MZ due to crossing over. Embryos from the two oocytes containing the unaffected gene (polar body PI type Z) were transferred in the same cycle 48 h after insemination. No pregnancy was established. The accuracy of the polar body diagnosis was confirmed by polymerase chain reaction (PCR) analysis of an oocyte that failed to fertilize.
BackgroundNoninvasive prenatal testing (NIPT) based on cell-free DNA in maternal circulation has been accepted worldwide by the clinical community since 2011 but limitations, such as maternal malignancy and fetoplacental mosaicism, preclude its full replacement of invasive prenatal diagnosis. We present a novel silicon-based nanostructured microfluidics platform named as “Cell Reveal™” to demonstrate the feasibility of capturing circulating fetal nucleated red blood cells (fnRBC) and extravillous cytotrophoblasts (EVT) for cell-based noninvasive prenatal diagnosis (cbNIPD).MethodsThe “Cell Reveal™” system is a silicon-based, nanostructured microfluidics using immunoaffinity to capture the trophoblasts and the nucleated RBC (nRBC) with specific antibodies. The automated computer analysis software was used to identify the targeted cells through additional immunostaining of the corresponding antigens. The identified cells were retrieved for whole genome amplification for subsequent investigations by micromanipulation in one microchip, and left in situ for subsequent fluorescence in situ hybridization (FISH) in another microchip. When validation, bloods from pregnant women (n = 24) at gestational age 11–13+6 weeks were enrolled. When verification, bloods from pregnant women (n = 5) receiving chorionic villus sampling or amniocentesis at gestation age 11+4–21 weeks with an aneuploid or euploid fetus were enrolled, followed by genetic analyses using FISH, short tandem repeat (STR) analyses, array comparative genomic hybridization, and next generation sequencing, in which the laboratory is blind to the fetal genetic complement.ResultsThe numbers of captured targeted cells were 1–44 nRBC/2 ml and 1–32 EVT/2 ml in the validation group. The genetic investigations performed in the verification group confirmed the captured cells to be fetal origin. In every 8 ml of the maternal blood being blindly tested, both fnRBC and EVT were always captured. The numbers of captured fetal cells were 14–22 fnRBC/4 ml and 1–44 EVT/4 ml of maternal blood.ConclusionsThis report is one of the first few to verify the capture of fnRBC in addition to EVT. The scalability of our automated system made us one step closer toward the goal of in vitro diagnostics.Electronic supplementary materialThe online version of this article (10.1186/s13039-017-0343-3) contains supplementary material, which is available to authorized users.
Chorionic villus sampling (CVS) in the first trimester of pregnancy provides a safe and effective method for the early prenatal diagnosis of cytogenetic abnormalities in multiple gestations. In this multicentre study involving 126 twin and 2 triplet gestations primarily at risk because of advanced maternal age, the overall success rate of obtaining an adequate villus sample from each fetus was 99.2 per cent. For women of advanced maternal age, the rate of combined losses of chromosomally normal fetuses due to spontaneous abortion, stillbirths, and neonatal deaths was 5.0 per cent, compared with a 4.0 per cent total loss rate following CVS in singleton pregnancies derived from the same population (Rhoads et al., 1989). There was a 100 per cent success rate in obtaining a cytogenetic analysis; a cytogenetic abnormality was present in five of the multiple gestations (3.9 per cent) and involved seven fetuses (2.7 per cent). There were no diagnostic errors and no cases of normal cytogenetic diagnosis followed by the birth of a cytogenetically abnormal newborn. Based on cases of XX/XY admixture, cell contamination derived either from maternal decidua or the other twin occurred in 6 of 256 samples (2.3 per cent), giving an overall estimate of the frequency of cell contamination of 4.6 per cent; these cases did not present a diagnostic problem. However, there were two cases (0.8 per cent) in which the fetal sex was incorrect, due either to complete maternal cell contamination or to the possibility that in error one twin was sampled twice.
CVS is the most reliable method of determining the karyotype of spontaneously aborted fetuses. The incidence of aneuploidy is much greater than in previous reports that analyzed passed products of conception. CVS should be offered to women who present with first-trimester spontaneous abortions.
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