常见问题:羊膜穿刺术
Amniocentesis is a prenatal test that can detect chromosomal differences, 比如那些导致唐氏综合症的基因, as well as extra or missing pieces of chromosomes, 称为拷贝数变体, some of which are associated with certain conditions.
这个测试, typically performed at 16 to 22 weeks of pregnancy, can also be used in at-risk fetuses to identify some genetic diseases caused by a difference in a single gene, 包括囊性纤维化, 镰状细胞病和泰-萨克斯病. Amniocentesis can also be used to screen for neural tube defects, which are birth defects of the brain and spine, 比如脊柱裂.
十大赌博平台排行榜, nurses and other members of the UCSF产前诊断中心 bring a wealth of expertise and experience to your care and have performed more than 40,000 amniocentesis procedures over the past 25 years.
Why choose amniocentesis over chronic villus sampling (CVS)?
虽然在怀孕后期进行 CVS, amniocentesis has the advantage of screening for neural tube defects, 比如脊柱裂. (Those who opt for CVS need to have a blood test later during pregnancy to screen for neural tube defects.)由于那个原因, amniocentesis is recommended if you have a child with a neural tube defect, 如果你自己也有这些情况, 或者是另一个亲生父母. Also, there is a slightly higher risk of miscarriage from CVS compared with amniocentesis.
首先你要见一位基因顾问, who will assess your pregnancy history and family history, explain options for prenatal screening and testing, 回答你的任何问题或疑虑. 这个预约可以亲自到 UCSF产前诊断中心 或者通过视频访问.
You'll then have an ultrasound to assess the location of the fetus and placenta and to evaluate fetal growth. 在羊膜穿刺术期间, 哪一种是在超声引导下进行的, a needle is inserted through the abdomen to remove a small amount of amniotic fluid. Most patients don't find the procedure painful, although some experience cramping or other minor discomfort.
样品被送到实验室进行测试. Most results are available within two weeks, although certain tests may take up to a month.
There is a small risk of miscarriage as a result of an amniocentesis. 大约是900分之一.
What are the possible results from amniocentesis?
- 正常的. A normal result indicates that the test did not identify evidence of the conditions it was checking for.
- 不正常的. An abnormal result indicates that the test identified a genetic difference in the pregnancy. 如果发生这种情况, you'll discuss the results and your options with a genetic counselor and other health care providers at our center, 还有你自己的十大赌博平台排行榜. For any decision you make, we offer referrals and support resources.
- 不确定的. An uncertain result indicates that a genetic difference was identified but its effect on the pregnancy is unclear. 如果发生这种情况, you'll discuss the results and your options with a genetic counselor and other health care providers at our center, 还有你自己的十大赌博平台排行榜. 可能会建议进行额外的检测.
大多数保险计划包括羊膜穿刺术, chorionic villus sampling and other prenatal tests, especially for pregnant people age 35 or older. You may need a referral from your primary care doctor or an authorization from your health plan to ensure coverage. Our office staff is available to help you with insurance questions.
加州大学旧金山分校健康 medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.