Amniocentesis Risks

Many healthcare providers suggest an amniocentesis test as a diagnostic tool after an abnormal triple test result. The test helps to find out any genetic or inherited abnormal traits in the fetus to determine any genetic disorders that may be present in the baby. If you are wondering whether or not you need to take this test, this article will cover some risks and gains to help you make up your mind.

Amniocentesis Procedure

When you go in for this procedure, the doctor will use ultrasound to determine a safe location in the amniotic sac. Once the doctor positions the safe location, a needle is used to enter the amniotic sac and fluid is safely collected. This procedure takes about 45 minutes and collection of the amniotic fluid takes about 5 minutes. The collected fluid is sent to the laboratory for further tests. The fluid contains cells that are shed from the fetus and these cells are used for further analysis. The results may take a few days to few weeks.

When and Why is the Procedure Performed

This procedure is usually performed between 14 to 20 weeks and sometimes as early as 11 weeks of pregnancy. In some cases, amniocentesis may be performed in the third trimester. The third trimester risks are lower and is not linked to premature labor. This procedure is also carried out to determine uterine infections in case of ruptured membranes. It also helps determine feral anemia in babies with Rh disease. In such cases, it also helps the doctor to decide whether the fetus requires blood transfusions to save its life. During the third trimester, lung maturity can also be assessed.

The Risks and Benefits

Although considered to be a safe procedure, as it is an invasive diagnostic test, it has its share of risks. There are some amniocentesis risks that should be noted before carrying out the procedure. These include:

• Miscarriage: The rate of risk of miscarriage is about 1 in 300 to 1 in 500. The chance of miscarriage is high if carried out before 14 weeks of pregnancy. Miscarriages happen due to infection in the uterus, the water breaks or labor is induced prematurely. The risk for twins or multiple pregnancy is same as the slight risk of miscarriage in normal pregnancies.
• Cramps and Vaginal Bleeding: Another risk of amniocentesis in some women is cramping and vaginal bleeding.
• Fetal Injury: In extremely rare cases, the needle comes in contact with the baby. This may happen in case the baby moves an arm or leg and comes in contact with the needle. It is very rare to observe serious needle injuries in fetus while performing the procedure.
• Rh Sensitization: Again in rare cases, the fetal blood cells enter the mother's bloodstream triggering an immune response. This happens when the mother is Rh negative and the fetus has Rh positive blood group. The doctor may give the mother, in such cases, Rh immunoglobulin drugs to prevent production of antibodies against the fetal blood cells.
• Uterine Infections: Sometimes, the procedure may trigger a uterine infection that may lead to miscarriage. If the mother has hepatitis B or hepatitis C, it may increase the risk of transmission to baby in first or second trimesters. There is an increase in the risk of HIV being transmitted from the mother to the baby. Thus, one should avoid it in third trimester.

Some other side effects include leakage of fluid and minor irritation at the puncture site. Let us now have a look at the benefits.

Amniocentesis helps detect chromosomal abnormalities. It also helps in detecting neural tube defects and genetic disorders. There is high level of accuracy of about 98 to 99% associated with the test. The test gives the probability of birth defects, not the severity of the abnormalities. It helps detect Trisomy 21 or Down syndrome, the most common chromosomal abnormality. It also helps detect cystic fibrosis and finds whether the lungs are mature to be able to breathe on their own. It also helps in detection of DNA paternity testing before delivery. The results have 99% accuracy rate in detection of paternity.

Amniocentesis is considered to be a safe procedure, and you should visit only qualified and experienced medical professionals to carry out the test. Make sure you discuss all the possibility and risks involved regarding the test with your doctor.