Amniocentesis is a test that requires sampling of amniotic fluid surrounding the fetus in the womb. This procedure is performed in order to determine any birth defects in fetus. It is generally recommended by doctors after 15 weeks of pregnancy.
Amniotic fluid consists of proteins, chemical enzymes and other necessary substances that are vital for the development of fetus. It serves as a layer of protection against injuries and infections. This fluid also contains cells from fetus, which hold genetic information and it is useful in determining chromosomal disorders such as Down’s syndrome and neural tube anomalies such as spina bifida. Amniocentesis may also be performed to identify any inherited chromosome abnormalities and family related metabolic disorders.
This procedure may also be done to know about fetal health, lung development and to identify any infections in the advanced stages of pregnancy. The results for checking genetic problems may be available within two weeks.
When is this procedure required?
- Amniocentesis is recommended to only those pregnant women who are at higher risk of fetal birth defects.
- If you are aged 35 years and above.
- If your regular screening tests show abnormal results.
- If you have a child with birth disabilities.
- If your family history suggests that there is a huge risk of certain disorders.
How it is done?
Amniocentesis is generally a painless process and does not need much preparation. Ultrasound scan will be required to know the position of umbilical cord, placenta, fetus and amniotic sac. Numbing medicine may be given to you in the form of injection on your abdomen. With the help of ultrasound, a thin, long needle will be inserted into the uterus and into amniotic layer. A small amount of amniotic fluid will be drawn into the needle, which will soon be replenished by your body.
What are the risks?
- This procedure is considered safe, but with a risk of 1% fetal loss, which is rare. It is only recommended in cases where there is a clear indication of a possible birth defect.
- After the procedure, about 1% of women may experience cramps, bleeding and fluid leakage from the sac. These problems may be resolved on their own in most cases.
- During the procedure, the needle may sometimes enter the fetus. This does not cause any harm, but the fetus needs monitoring after the test.
- Being an invasive procedure, this test carries certain risk of infection.
- There may be a risk of premature delivery.
- In some cases, the test results may not be accurate.
- Before going ahead with the procedure, it is important to inform your doctor about any medications you use, any medicinal allergies or if have any bleeding disorders. Certain drugs can interfere with blood clotting.
- You should also mention your Rh type blood grouping. In case you are Rh negative, your blood cells may interfere with those of the fetus’ Rh positive cells. This can affect the red blood cells of the baby and cause them to break down.