Chromosomal karyotyping analysis has been considered as the gold standard for cytogenetic diagnosis and an effective measure for preventing birth defects. However, conventional karyotyping analysis relies heavily on manual recognition, which is time-consuming and labor-intensive. The application of an efficient intelligent chromosomal karyotyping precise auxiliary diagnosis system in clinical practice can significantly reduce the analysis time and greatly improve the efficiency, increase the detection rate for low-percentage mosaicisms, and promote homogenization between laboratories. This can effectively enhance the capacity and level of cytogenetic diagnosis. With the continuous application of such system in the field of karyotyping analysis, a substantial amount of clinical application data and experience has been accumulated. This consensus has been formulated after multiple rounds of discussion by experts from the clinical application collaboration group of the efficient intelligent chromosomal karyotyping precise auxiliary diagnosis system. It aims to provide a reference for peers to better utilize intelligent auxiliary diagnosis systems during chromosomal karyotyping analysis and promote the standardized development of karyotyping analysis technology.

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BACKGROUND: Practice variation in recurrent pregnancy loss (RPL) care is common. International guidelines vary in their recommendations for the management of RPL couples, which could lead to an increase of cross border reproductive care. Currently, the Dutch RPL guideline is being adapted from the European Society for Human Reproduction and Embryology (ESHRE) guideline. We aim to identify discrepancies between RPL guidelines and RPL practice. These discrepancies could be considered in the development of a new guideline and implementation strategies to promote adherence to new recommendations.
METHODS: A nationwide survey on the management of RPL patients was conducted across all 107 hospital-based obstetrics and gynaecology practices in the Netherlands. The survey was sent via the Dutch Society for Obstetricians and Gynaecologists to all affiliated clinicians. The questionnaire consisted of 36 questions divided in four sections: clinician\'s demographics, RPL definition, investigations and therapy. The data were compared to the recommendations given by the Dutch national guideline and the most recent guideline of the ESHRE.
RESULTS: All hospital-based practices (100%; n = 107) filled in the online questionnaire. The majority of respondents defined RPL similarly, as two or more pregnancy losses (87.4%), not obligatory consecutive (93.1%). More than half of respondents routinely perform thrombophilia screening ( 58%), although not advised by the ESHRE, while thyroid function (57%), thyroid auto-immunity (27%) and β2-glycoprotein antibodies (42%) in the context of antiphospholipid syndrome (APS) are recommended but investigated less often. Regarding parental karyotyping, 20% of respondents stated they always perform parental karyotyping, without prior risk assessment. because of RPL. Treatment for hereditary thrombophilia was frequently (43.8% (n = 137)) prescribed although not recommended. And finally, a considerable part (12-16%) of respondents prescribe medication in case of unexplained RPL.
CONCLUSIONS: While many clinicians perform investigations recommended by the ESHRE, there is a considerable variation of RPL practice in the Netherlands. We identified discrepancies between RPL guidelines and RPL practice, providing possibilities to focus on multifaceted implementation strategies, such as educational intervention, local consensus processes and auditing and feedback. This will improve the quality of care provided to RPL patients and may diminish the necessity felt by patients to turn to multiple opinions or cross border reproductive care.

Karyotyping analysis is a classical cytogenetic method for the prenatal diagnosis of fetal chromosomal aberrations. In order to standardize fetal chromosomal karyotyping analysis and adapt to the development of medical genetics technology, the Committee for the Prevention and Control of Birth Defect, Chinese Association of Preventive Medicine has organized the formulation of this guideline. The content has covered general requirements and standards for the analysis of fetal chromosomal karyotypes, analysis of chromosomal mosaicisms, and methods for determining the resolution of G-banding, etc., with the purpose to serve the clinical practice.

In 2019, the Korean Society of Maternal-Fetal Medicine developed the first Korean clinical practice guidelines for prenatal aneuploidy screening and diagnostic testing. These guidelines were developed by adapting established clinical practice guidelines in other countries that were searched systematically, and the guidelines aim to assist in decision making of healthcare providers providing prenatal care and to be used as a source for education and communication with pregnant women in Korea. This article delineates clinical practice guidelines specifically for maternal serum screening for fetal aneuploidy and cell-free DNA (cfDNA) screening. A total of 19 key questions (12 for maternal serum and 7 for cfDNA screening) were defined. The main recommendations are: 1) Pregnant women should be informed of common fetal aneuploidy that can be detected, risks for chromosomal abnormality according to the maternal age, detection rate and false positive rate for common fetal aneuploidy with each screening test, limitations, as well as the benefits and risks of invasive diagnostic testing, 2) It is ideal to give counseling about prenatal aneuploidy screening and diagnostic testing at the first prenatal visit, and counseling is recommended to be given early in pregnancy, 3) All pregnant women should be informed about maternal serum screening regardless of their age, 4) cfDNA screening can be used for the screening of trisomy 21, 18, 13 and sex-chromosome aneuploidy. It is not recommended for the screening of microdeletion, 5) The optimal timing of cfDNA screening is 10 weeks of gestation and beyond, and 6) cfDNA screening is not recommended for women with multiple gestations. The guideline was reviewed and approved by the Korean Academy of Medical Sciences.

Although non-invasive prenatal testing has been widely used, it has certain limitations. As the gold standard of prenatal diagnosis, G-banding karyotype analysis is time-consuming and laborious. Fluorescence in situ hybridization (FISH), as a method for detecting samples with non-radioactive signals, does not require cell culture and has a short turnover time, and can diagnose aneuploidies of chromosomes 13, 18, 21, X, Y with efficiency, which can solve the problems such as insufficient testing ability and long diagnosis period for karyotype analysis. To standardize the procedures of prenatal FISH assay and enhance laboratory quality management, the Expert Committee of the Prenatal Screening and Diagnosis Laboratory of the Clinical Test Center of the National Health Commission and the Inter-laboratory Quality Assessment Committee of the Neonatal Genetic and Metabolic Disease Screening Laboratory have formulated this consensus.

Couples with recurrent pregnancy loss (RPL) are often referred to reproductive specialists to help determine the reason for their repeated losses. This review will help to develop a strategy that is effective in providing a diagnosis, efficient to administer, and cost-effective to the healthcare system.
International societies have published different recommendations for the evaluation of RPL, they consider it appropriate to initiate an evaluation after two (or three) clinical miscarriages. On the contrary, the clinician who follows these guidelines will only be able to offer a possible explanation to fewer than half of the couples being evaluated. Recently, genetic testing of miscarriage tissue using 24-chromosome microarray (CMA) analysis at the time of the second pregnancy loss coupled with testing based on society guidelines has been shown provide an explanation in more than 90% of cases.
New guidelines for the complete evaluation of RPL should consider adding 24-CMA testing on the miscarriage tissue. Providing couples with an explanation for recurrent loss assists them in dealing with the loss and discourages the clinician from instituting unproven therapies. Truly unexplained pregnancy loss can be reduced to less than 10% with this new algorithm. Incorporation of these strategies will result in significant cost savings to the healthcare system.

Recurrent pregnancy loss (RPL) is defined as two or more pregnancy losses. It affects <5% of couples. There are many proposed causes; however, in a significant proportion of cases, the cause is unknown.
The aim of this paper is to provide a summary of the aetiology, investigations and management of RPL, which is based on the three most recent international guidelines on RPL (European Society of Human Reproduction and Embryology, 2017; American Society for Reproductive Medicine, 2012; and the Royal College of Obstetricians and Gynaecologists, 2011).
Management of RPL should occur in a specialised clinic. Appropriate investigations include karyotyping of parents and products of conception, two-dimensional/three-dimensional ultrasonography with sonohysterography, thyroid function tests, and antibodies and testing for acquired thrombophilias. Management options encompass some lifestyle modifications for smoking, alcohol, illicit drug use and caffeine consumption. Acquired thrombophilias should be treated with unfractionated heparin and low-dose aspirin.

The previous edition of the consensus guidelines of the International Workshop on Chronic Lymphocytic Leukemia (iwCLL), published in 2008, has found broad acceptance by physicians and investigators caring for patients with CLL. Recent advances including the discovery of the genomic landscape of the disease, the development of genetic tests with prognostic relevance, and the detection of minimal residual disease (MRD), coupled with the increased availability of novel targeted agents with impressive efficacy, prompted an international panel to provide updated evidence- and expert opinion-based recommendations. These recommendations include a revised version of the iwCLL response criteria, an update on the use of MRD status for clinical evaluation, and recommendations regarding the assessment and prophylaxis of viral diseases during management of CLL.

The American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal-Fetal Medicine (SMFM) recommend chromosomal microarray analysis (CMA) for prenatal diagnosis in cases with 1 or more fetal structural abnormalities. For patients who elect prenatal diagnosis and have a structurally normal fetus, either microarray or karyotype is recommended. This study evaluates the frequency of clinically significant chromosomal abnormalities (CSCA) that would have been missed if all patients offered the choice between CMA and karyotyping chose karyotyping.
A total of 3223 prenatal samples undergoing CMA were evaluated. Cases were categorized into 2 groups: those that met ACOG guidelines for CMA versus those that met ACOG guidelines for either CMA or karyotype.
Of the 3223 cases, 1475 (45.8%) met ACOG recommendations for CMA, and 1748 (54.2%) met recommendations for either CMA or karyotype. In patients who could have elected either CMA or karyotype, 2.5% had CSCA that would have been missed if the patient had elected to pursue karyotype.
This study suggests that 2.5% of patients will have a CSCA that may be missed if the guidelines continue to suggest that CMA and karyotyping have equivalent diagnostic value for patients without a fetal structural abnormality.