Obstet Gynecol. 2016 May;127(5):e108-e122. doi: 10.1097/AOG.0000000000001405.
Prenatal genetic diagnostic testing is intended to determine, with as much certainty as possible, whether a specific genetic disorder or condition is present in the fetus. In contrast, prenatal genetic screening is designed to assess whether a patient is at increased risk of having a fetus affected by a genetic disorder. Originally, prenatal genetic testing focused primarily on Down syndrome (trisomy 21), but now it is able to detect a broad range of genetic disorders. Although it is necessary to perform amniocentesis or chorionic villus sampling (CVS) to definitively diagnose most genetic disorders, in some circumstances, fetal imaging with ultrasonography, echocardiography, or magnetic resonance imaging may be diagnostic of a particular structural fetal abnormality that is suggestive of an underlying genetic condition.The objective of prenatal genetic testing is to detect health problems that could affect the woman, fetus, or newborn and provide the patient and her obstetrician-gynecologist or other obstetric care provider with enough information to allow a fully informed decision about pregnancy management. Prenatal genetic testing cannot identify all abnormalities or problems in a fetus, and any testing should be focused on the individual patient's risks, reproductive goals, and preferences. It is important that patients understand the benefits and limitations of all prenatal screening and diagnostic testing, including the conditions for which tests are available and the conditions that will not be detected by testing. It also is important that patients realize that there is a broad range of clinical presentations, or phenotypes, for many genetic disorders and that results of genetic testing cannot predict all outcomes. Prenatal genetic testing has many benefits, including reassuring patients when results are normal, identifying disorders for which prenatal treatment may provide benefit, optimizing neonatal outcomes by ensuring the appropriate location for delivery and the necessary personnel to care for affected infants, and allowing the opportunity for pregnancy termination.The purpose of this Practice Bulletin is to review the current status of prenatal genetic diagnostic testing and the evidence supporting its use. For information regarding screening for fetal aneuploidy, refer to Practice Bulletin No. 163, Screening for Fetal Aneuploidy.
产前遗传诊断检测旨在尽可能确定胎儿是否存在特定的遗传疾病或病症。相比之下，产前遗传筛查旨在评估患者是否有更高的风险，其胎儿患有遗传疾病。最初，产前遗传检测主要集中在唐氏综合征（21 三体）上，但现在它能够检测到广泛的遗传疾病。尽管大多数遗传疾病的明确诊断都需要进行羊膜穿刺术或绒毛膜活检（CVS），但在某些情况下，超声、超声心动图或磁共振成像等胎儿成像可能可以诊断出特定的结构胎儿异常，这提示存在潜在的遗传状况。产前遗传检测的目的是发现可能影响女性、胎儿或新生儿的健康问题，并为患者及其妇产科医生或其他产科护理提供者提供足够的信息，以便对妊娠管理做出充分知情的决定。产前遗传检测无法识别胎儿的所有异常或问题，任何检测都应集中在个体患者的风险、生殖目标和偏好上。患者了解所有产前筛查和诊断检测的益处和局限性非常重要，包括可用测试的条件和测试无法检测到的条件。患者还应该认识到，许多遗传疾病都有广泛的临床表现或表型，并且遗传测试的结果不能预测所有结果。产前遗传检测有很多好处，包括当结果正常时可以使患者安心，确定可能通过产前治疗获益的疾病，通过确保适当的分娩地点和照顾受影响婴儿的必要人员来优化新生儿结局，并为终止妊娠提供机会。本实践公告的目的是审查产前遗传诊断检测的现状和支持其使用的证据。有关胎儿非整倍体筛查的信息，请参阅实践公告 No. 163，胎儿非整倍体筛查。
