- What are prenatal screening tests?
- Which conditions do the screening tests cover?
- What are the screening options in California?
- Who is eligible for prenatal genetic screening?
- What kind of results might I receive?
- Do I need prenatal screening?
- Does prenatal screening have limitations?
- Are there risks associated with prenatal screening?
- What are the next steps after a positive test result?
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常见问题:出生缺陷和常见遗传疾病的产前筛查
What are prenatal screening tests?
产前检查是一种测量怀孕时患几种常见遗传疾病风险的方法, including Down syndrome. Whether to have these tests is up to the individual. 可以检测到的疾病通常是由怀孕期间发生的基因变化引起的,而不是从亲生父母那里遗传的疾病. 产前检查还可以评估某些出生缺陷的风险.
本页描述的筛查选项被认为是非侵入性的. 它们是通过血液检查或超声波检查来进行的.
Which conditions do the screening tests cover?
- Down syndrome. Also called trisomy 21, 当胎儿有多余的21号染色体拷贝(全部或部分)时,就会发生唐氏综合症. 患有这种疾病的婴儿更有可能出现某些先天缺陷, such as a heart or intestinal abnormality. 患有唐氏综合症的人有明显的外表和轻度到中度的智力残疾. Most live well into adulthood. Learn more about prenatal testing options for Down syndrome.
- Trisomy 18 and trisomy 13. 这些染色体紊乱导致严重的智力残疾和身体许多部位的医疗问题. 大多数患有其中一种疾病的婴儿都活不过第一年.
- Neural tube defects. 这些神经性先天缺陷会影响大脑或脊髓. 最常见的神经管缺陷是脊柱裂(一种脊柱畸形)和无脑畸形(大脑或颅骨的一部分缺失)。.
- 一些产前筛查测试可以评估某些其他出生缺陷的风险, including problems in the development of the abdominal wall.
What are the screening options in California?
All pregnant individuals in California have access to California prenatal screening (CA PNS). 这种非侵入性筛查的过程,被称为顺序综合筛查,包括两个部分:
- Cell-free DNA screening. This blood test, done at least 10 weeks into a pregnancy, can assess the risk for Down syndrome, trisomy 18 and trisomy 13. The test can also predict the sex of the fetus.
- Maternal serum alpha-fetoprotein (MSAFP) screening. This blood test, done when the pregnancy is between 15 and 21 weeks, can assess the risk of neural tube defects, as well as defects in the abdominal wall.
加州大学旧金山分校还提供并推荐额外的筛查选项:
- Nuchal translucency (NT) screening. This ultrasound, done when the pregnancy is between 11 and 14 weeks, measures the space behind the fetus' neck, 哪些可以提示可能的染色体改变或出生缺陷.
Who is eligible for prenatal genetic screening?
Most pregnant people are eligible. However, 符合以下任何类别的人都不符合资格, due to decreased testing accuracy:
- Pregnant with more than two fetuses
- 双胞胎消失综合症(失去一个双胞胎)影响当前妊娠
- 接受过器官移植或目前患有活动性癌症的人
What kind of results might I receive?
- Positive. The fetus has an increased risk for a specific condition.
- Negative. The fetus doesn't have an increased risk for the condition.
- Indeterminate. 该测试没有提供足够的信息来显示胎儿是否有更高的患病风险. If this happens, your provider can readminister the test.
A prenatal test helps to assess risk but is not a diagnosis. 阳性或阴性结果并不能明确表明怀孕是否有特殊情况.
产前筛查是可选的,你的十大赌博平台排行榜会支持你的决定. 一些患者选择产前筛查,因为了解遗传十大赌博靠谱网络平台的可能风险有助于他们为怀孕做准备或做出决定.
Does prenatal screening have limitations?
没有任何测试可以检测出怀孕期间所有可能的健康和发育问题.
Prenatal screening tests are not 100% accurate. False positives and false negatives occur. 这些测试也不是诊断性的:它们显示的是某种特定疾病的风险, not whether the fetus is affected by a specific condition.
Other genetic tests, including chorionic villus sampling and amniocentesis,可能会提供有关妊娠遗传风险的更明确信息. 和遗传咨询师谈谈,了解更多关于你的选择.
Are there risks associated with prenatal screening?
本页描述的检查是血液检查或超声波检查,不会对怀孕造成任何身体风险.
虽然这种情况很少发生,但产前基因检测可以揭示你自己的健康信息. 例如,你可能会发现你有一个染色体异常.
What are the next steps after a positive test result?
If a test reveals an increased risk in your pregnancy, 你将被转介到遗传咨询师那里讨论你的选择. Your genetic counselor may recommend further testing.
如果你对产前基因筛查和测试有疑问, 或者你想预约一个遗传咨询师, please contact the UCSF Prenatal Diagnostic Center.
加州大学旧金山分校健康医学专家已经审查了这些信息. 它仅用于教育目的,并不打算取代您的十大赌博平台排行榜或其他医疗保健提供者的建议. 我们鼓励您与您的供应商讨论您可能遇到的任何问题或疑虑.
Recommended reading
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FAQ: Genetic Carrier Screening
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