font size

Amniocentesis (cont.)

Medical Author:
Medical Editor:

What does amniocentesis show?

Amniocentesis is very accurate in detecting chromosomal abnormalities and the gender of the fetus. Occasionally, the fetal cells harvested by amniocentesis do not grow in the culture and no chromosome data can be obtained. Additionally, the doctor occasionally is unable to extract fluid from the uterus during amniocentesis due to a variety of technical reasons. In both instances, the procedure can be repeated.

Amniocentesis testing for lung maturity can help the doctor make decisions regarding timing of delivery for women in premature labor, or those with diabetes or other medical conditions requiring a possible early delivery. Lung maturity testing is not perfect. In rare instances, a baby is born with apparently mature lungs but still experiences difficulty breathing.

The AFP (alpha feto protein) blood test is currently available and can be used to screen for neural tube defects such as spina bifida and Down's syndrome. An elevated AFP blood level may indicate the possibility that the fetus has a defect in brain and spinal cord development. A low AFP level may indicate the potential for Down's syndrome. When abnormal levels of AFP are found, further evaluation with ultrasound and amniocentesis can be done to look for birth defects and chromosomal abnormalities.

Amniocentesis can also help determine if there are specific genetic problems present in the fetus. Testing for Tay-Sachs disease, cystic fibrosis, sickle cell anemia, and other inherited disorders can be performed on samples of amniotic fluid. Checking the cells for specific genes can now be done on the fetal cell cultures. It is also possible to look for a specific protein in the amniotic fluid that can signal a genetic abnormality. Testing for genetic (inherited) diseases is not routinely performed, but is available.

Another common reason for performing amniocentesis is to determine if the fetal lungs are mature enough so that the baby can be safely delivered before the due date. If the fetal lungs are not mature, an attempt can be made to stop premature labor with medications. If the lung tissues are mature, it may be safe for the premature baby to be born. This test can also help in the timing of delivery when the due date is uncertain.

Occasionally, a pregnant woman may have a fever without an obvious site of infection. In these instances, an amniocentesis may be performed to determine if the cause of the mother's fever is from an intrauterine infection, when the source of the infection is unclear.

The overall possibility of birth defects in any pregnancy is approximately 3%. For defects such as cleft lip, hernia, and extra fingers or toes, there are no prenatal screening tests and amniocentesis will not be of benefit. Ultrasound is the only helpful test in detecting these defects in the fetus.

Medically Reviewed by a Doctor on 2/27/2014

Patient Comments

Viewers share their comments

Amniocentesis - Experience Question: Please describe your experience with amniocentesis.
Source: MedicineNet.com
http://www.medicinenet.com/amniocentesis/article.htm

Parenting and Pregnancy

Get tips for baby and you.

advertisement
advertisement
Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations

NIH talks about Ebola on WebMD