Best Practice & Research Clinical Obstetrics & Gynaecology最新文献

Genetic testing for prenatal diagnosis in the pre-genomic era primarily focused on detecting common fetal aneuploidies, using methods that combine maternal factors and imaging findings. The genomic era, ushered in by the emergence of new technologies like chromosomal microarray analysis and next-generation sequencing, has transformed prenatal diagnosis. These new tools enable screening and testing for a broad spectrum of genetic conditions, from chromosomal to monogenic disorders, and significantly enhance diagnostic precision and efficacy. This chapter reviews the transition from traditional karyotyping to comprehensive sequencing-based genomic analyses. We discuss both the clinical utility and the challenges of integrating prenatal exome and genome sequencing into prenatal care and underscore the need for ethical frameworks, improved prenatal phenotypic characterization, and global collaboration to further advance the field.

Non-invasive prenatal diagnosis of monogenic disorders is becoming integrated into routine clinical care for many indications. This is carried out by testing cell-free DNA extracted from the plasma portion of a maternal blood sample. The cell-free DNA is low in concentration, and consists of a mixture of maternal and fetally-derived DNA which are not easy to separate. Methods used therefore need to be rapid, sensitive and specific, including real-time PCR, digital PCR and next generation sequencing with complex algorithms. Testing may be required for pregnancies with an increased chance of a monogenic disorder due to family history or carrier status, or where there are specific abnormalities identified by ultrasound scan. In these situations, testing is considered to be diagnostic and therefore does not require confirmation by invasive testing. With increased access to genomic technologies, and more diagnoses for rare disease patients, future demand for NIPD and possibilities during pregnancy will continue.

Genome-wide sequencing, which includes exome sequencing and genome sequencing, has revolutionized the diagnostics of genetic disorders in both postnatal and prenatal settings. Compared to exome sequencing, genome sequencing enables the detection of many additional types of genomic variants, although this depends on the bioinformatics pipelines used. Variant classification might vary among laboratories. In the prenatal setting, variant classification may change if new fetal phenotypic features emerge as the pregnancy progresses. There is still a need to evaluate the incremental diagnostic yield of genome sequencing compared to exome sequencing in the prenatal setting. This article reviews the advantages and limitations of genome sequencing, with an emphasis on fetal diagnostics.

The role of genetic testing within maternal medicine is expanding. Advancing technology and the increasing availability of genetic testing have seen more patients receiving a genetic diagnosis than ever before. Improved healthcare and understanding of these rare diseases means that many patients are living well into their reproductive years and starting families.

Individual diseases are considered by their patterns of inheritance i.e. autosomal recessive, autosomal dominant and chromosomal diseases. This chapter specifically addresses the following examples and outlines an approach to pre-conceptual and pregnancy management; autosomal recessive (cystic fibrosis, phenylketonuria), autosomal dominant (osteogenesis imperfecta, vascular Ehlers-Danlos syndrome) and chromosomal (Turner syndrome).

For many rare and ultrarare genetic diseases, there may be no clear guidelines or consensus on the correct management in pregnancy. This chapter seeks to provide a framework for the clinician to use to address the unique needs and risk profile of these patients in pregnancy and pre-conceptually and plan accordingly. The role of pharmacogenetics in maternal medicine, the future of education in genetics for patients and clinicians and the important role of genetic counselling are all considered in this chapter.

This overview highlights the important role of genetics in maternal medicine and how this can inform management and planning for the safe care of mother and baby.

The World Health Organization includes oral emergency contraception (EC) in the list of essential medicines. Ulipristal acetate (UPA) and levonorgestrel (LNG) are the recommended oral methods. UPA has superior efficacy and a comparable side effect profile compared with LNG. Both work by inhibiting or delaying ovulation, so that sperm present in the reproductive tract will have lost their fertilising ability by the time the oocyte is eventually released. Neither LNG nor UPA at the EC doses have significant effects on the endometrium and are unable to prevent implantation. Mifepristone can also be used for EC but its availability is limited to few countries. LNG is less effective in women with a body mass index over 26 kg/m² or weight over 70 kg. Hormonal contraception can be quickstarted immediately following LNG, or five days following UPA. LNG-releasing intrauterine devices and cyclo-oxygenase inhibitors are promising options for EC to be further studied.

Routine antenatal care includes history, examination, and several standard laboratory tests. Other than the original objectives, the generated data is seldom utilised for screening for adverse obstetric and perinatal outcomes. Although new approaches and sophisticated tests improve prediction of complications such as pre-eclampsia, these may not be available globally. Maternal age, race/ethnicity, anthropometry, and method of conception can influence the occurrence of pregnancy complications. The importance of medical and obstetric history is well documented but often ignored. Routine test results including blood picture, hepatitis B and rubella serology, and sexually transmitted diseases, have additional health implications. The awareness of, and the ability to utilise, available antenatal data and tests in obstetric management will enhance individualised obstetric risk assessment thus facilitating the targeting of high-risk gravidae for further management, including the use of specific and technology-driven tests where available, and close monitoring and treatment, in a cost-effective manner.

The Dutch NIPT Consortium, a multidisciplinary collaboration of stakeholders in prenatal care initiated and launched the TRIDENT studies. The goal of the TRIDENT studies was to implement non-invasive prenatal testing (NIPT), first as a contingent (second-tier) and later as a first-tier test, and to evaluate this implementation. This paper describes how NIPT can be successfully implemented in a country or state. Important factors include the significance of forming a consortium and encouraging cooperation among relevant stakeholders, appropriate training for obstetric care professionals, and taking into account the perspectives of pregnant women when implementing prenatal tests. We describe the advantages of high sensitivity and specificity when comparing contingent NIPT with first-tier NIPT. This paper emphasizes the value of pre- and post-test counselling and the requirement for a standardized method of information delivery and value clarification, to assist couples in decision making for prenatal screening.

Intimate partner violence (IPV) during pregnancy emerges as a compelling and urgent concern within the domain of public health, casting a long shadow over a substantial cohort of women. Its pernicious consequences extend beyond the individual, enveloping the well-being of both the mother and the fetus, giving rise to an elevated risk of preterm birth, low birth weight, fetal harm, and maternal psychological distress, including depression, anxiety, post-traumatic stress disorder, and, tragically, maternal mortality. Despite the prevalence of IPV being comparable to other conditions like gestational diabetes and preeclampsia, a universal screening protocol for IPV remains absent globally. We reviewed the clinical guidelines and practices concerning IPV screening, painstakingly scrutinizing their contextual nuances across diverse nations. Our study unveils multifaceted challenges of implementing universal screening. These hurdles encompass impediments to victim awareness and disclosure, limitations in healthcare providers' knowledge and training, and the formidable structural barriers entrenched within healthcare systems. Concurrently, we delve into the potential biomarkers intricately entwined with IPV. These promising markers encompass inflammatory indicators, epigenetic and genetic influences, and a diverse array of chemical compounds and proteins. Lastly, we discussed various criteria for universal screening including (1) valid and reliable screening tool; (2) target population as pregnant women; (3) scientific evidence of screening programme; and (4) integration of education, testing, clinical services, and programme management to minimise the challenges, which are paramount. With the advancement of digital technology and various biomarkers identification, screening and detecting IPV in clinical settings can be conducted systemically. A systems-level interventions with academia-community-indutrial partnerships can help connect pregnant women to desire support services to avoid adverse maternal and child health outcomes.

Antenatal screening with ultrasound identifies fetal structural anomalies in 3–6% of pregnancies. Identification of anomalies during pregnancy provides an opportunity for counselling, targeted imaging, genetic testing, fetal intervention and delivery planning. Ultrasound is the primary modality for imaging the fetus in pregnancy, but magnetic resonance imaging (MRI) is evolving as an adjunctive tool providing additional structural and functional information. Screening should start from the first trimester when more than 50% of severe defects can be detected. The mid-trimester ultrasound balances the benefits of increased fetal growth and development to improve detection rates, whilst still providing timely management options. A routine third trimester ultrasound may detect acquired anomalies or those missed earlier in pregnancy but may not be available in all settings. Targeted imaging by fetal medicine experts improves detection in high-risk pregnancies or when an anomaly has been detected, allowing accurate phenotyping, access to advanced genetic testing and expert counselling.

Preimplantation genetic testing (PGT) involves taking a biopsy of an early embryo created through in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). Genetic testing is performed on the biopsy, in order to select which embryo to transfer. PGT began as an experimental procedure in the 1990s, but is now an integral part of assisted human reproduction (AHR). PGT allows for embryo selection which can reduce the risk of transmission of inherited disease and may reduce the chance of implantation failure and pregnancy loss. This is a rapidly evolving area, which raises important ethical issues. This review article aims to give a brief history of PGT, an overview of the current evidence in PGT along with highlighting exciting areas of research to advance this technology.