绒毛取样

定义

绒毛取样 (CVS) is a test some pregnant women have to screen their baby for genetic problems.

选择的名字

CVS; Pregnancy - CVS; 遗传咨询 - CVS

如何执行测试

CVS can be done through the cervix (transcervical) or through the belly (transabdominal). Miscarriage rates are slightly higher when the test is done through the cervix.

The transcervical procedure is performed by inserting a thin plastic tube through the vagina and cervix to reach the placenta. Your health care provider uses ultrasound images to help guide the tube into the best area for sampling. A small sample of chorionic villus (placental) tissue is then removed.

The transabdominal procedure is performed by inserting a needle through the abdomen and uterus and into the placenta. Ultrasound is used to help guide the needle, and a small amount of tissue is drawn into the syringe.

The sample is placed in a dish and evaluated in a lab. 测试结果大约需要2周.

如何准备考试

Your provider will explain the procedure, its risks, and alternative procedures such as 羊膜穿刺术.

You will be asked to sign a consent form before this procedure. 你可能会被要求穿病号服.

The morning of the procedure, you may be asked to drink fluids and refrain from urinating. Doing so fills your bladder, which helps your provider see where to best guide the needle.

Tell your provider if you are allergic to iodine or shellfish, or if you have any other allergies.

考试的感觉如何

超声波不疼. A clear, water-based gel is applied to your skin to help with the transmission of the sound waves. A hand-held probe called a transducer is then moved over your belly area. In addition, your provider may apply pressure on your abdomen to find the position of your uterus.

The gel will feel cold at first and may irritate your skin if not washed off after the procedure.

Some women say the vaginal approach feels like a 巴氏早期癌变探查试验 有一些不适和压力感. There may be a small amount of vaginal bleeding following the procedure.

An obstetrician can perform this procedure in about 5 minutes, after preparation.

为什么要进行测试

The test is used to identify any genetic disease in your unborn baby. It is very accurate, and it can be done very early in a pregnancy.

任何孕期都可能出现遗传问题. However, the following factors increase the risk:

• 年长的母亲
• 有遗传问题的怀孕史
• 遗传疾病家族史

遗传咨询 在手术前建议做什么. This will allow you to make an unhurried, informed decision about options for prenatal diagnosis.

CVS can be done sooner in pregnancy than 羊膜穿刺术, most often at about 10 to 12 weeks.

CVS未检测到:

• Neural tube defects (these involve the spinal column or brain)
• Rh不相容 (this occurs when a pregnant woman has Rh-negative blood and her unborn baby has Rh-positive blood)
• 不是由于遗传原因造成的出生缺陷
• Issues related to brain function, such as autism and intellectual disability

正常的结果

A normal result means there are no signs of genetic defects in the developing baby. 尽管测试结果非常准确, no test is 100% accurate at testing for genetic problems in a pregnancy.

异常结果意味着什么

This test can help detect hundreds of genetic disorders. Abnormal results may be due to many different genetic conditions, including:

• 唐氏综合症
• 人
• 家族黑蒙性白痴病

Talk to your provider about the meaning of your specific test results. 询问你的供应商:

• How the condition or defect may be treated either during or after the pregnancy
• What special needs your child may have after birth
• What other options you have about maintaining or ending your pregnancy

风险

The risks of CVS are only slightly higher than those of 羊膜穿刺术.

可能的并发症包括:

• 出血
• 感染
• 流产(100名妇女中有1人流产)
• Rh与母亲不相容
• Rupture of membranes which may lead to miscarriage

注意事项

如果你的血是Rh阴性, you may receive a medicine called Rho(D) immune globulin (RhoGAM and other brands) to prevent Rh不相容.

You will receive a follow-up ultrasound 2 to 4 days after the procedure to make sure your pregnancy is proceeding normally.

参考文献。

程是. 产前诊断. 见:Gleason CA, Juul SE编. 艾弗里新生儿病. 10日艾德. Philadelphia, PA: Elsevier; 2018:chap 18.

Driscoll DA, Simpson JL. 基因筛查和诊断. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8日艾德. Philadelphia, PA: Elsevier; 2021:chap 10.

杜高夫L，瓦普纳RJ. 先天性疾病的产前诊断. In: Lockwood CJ, Copel JA, Dugoff L，等编. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 9日艾德. Philadelphia, PA: Elsevier; 2023:chap 30.

Graham GM, Park JS, Norwitz ER. 产前胎儿评估与治疗. In:陈德华，黄春华，曾立荣，等编. Chestnut's Obstetric Anesthesia: Principles and Practice. 6日艾德. Philadelphia, PA: Elsevier; 2020:chap 6.