In the uterus your baby is surrounded by water-like liquids called amniotic fluid. As your baby grows, just like adults, it sheds cells called fetal skin cells or alpha-fetoproteins (AFP). These cells contain very important clues about your baby’s health and development. Extensive testing, including testing at the genetic level, can be performed on the contents of amniotic fluids if you can get to it.
The process of removing a very small amount of the amniotic fluid from the uterine sac is called amniocentesis. A fine needle is inserted into the uterus through the abdomen to extract a small amount of this fluid, usually less than 30 ml. To assist the placement of the needle, sonography imaging is used. Once the fluid is extracted it can be sent to a lab for testing.
What can an amniocentesis tell you
While most women will not need amniocentesis, some women with risk factors are encouraged to have this procedure done. Amniocentesis can reveal certain conditions such as Down’s syndrome and spina Bifida prior to birth. Down’s syndrome is chromosomal abnormality that impacts the appearance and mental development of the child. The risk factors considered by doctors as to whether a woman needs amniocentesis include, the age of the woman (typically over 35 years of age), family history of genetic disorders or birth defects, previous delivery of child with birth defects or an abnormal sonography scan.
Besides Down’s syndrome and spina bifida, amniocentesis can also be used to detect other disorders such as Sickle cell disease, MD (Muscular Dystrophy), Cystic Fibrosis, and Anencephaly. Amniocentesis can also be used to determine the sex of the fetus, although in India it cannot be revealed to the parents.
What does the amniocentesis involve
Amniocentesis is typically performed towards the end of the first trimester to the early part of the second trimester. On rare occasions they can be performed much later when infection in the amniotic fluid is detected.
Like all procedures, there is a small risk of loss of pregnancy due to this procedure. Other risks include infection and pre-term labor. However these risks are very low, usually less than one percent. No matter how low the risks, amniocentesis is only performed when the doctor feels that the benefit of such a procedure outweighs the risk.
During the procedure, sonography is used to identify the location and position of the fetus. An area with a generous amount of amniotic fluid is located. The area of the abdomen above this area is cleaned and disinfected. It is not uncommon for the doctor performing this procedure to apply some form of local anesthetic. While continuing to use the sonography as a guide a long fine needle is inserted into the amniotic sac. Using a syringe a small amount of this fluid is retrieved. Assuming no complications arise, this procedure from preparation to completion should last no more than half an hour.
After the procedure you may experience discomfort or some cramping. It is best to rest for the remainder of the day avoiding any activity that would require you to carry anything heavy. You should call your doctor right away if you have any form of bleeding or develop fevers as this may indicate the start of an infection.