Fetal sampling

Amniocentesis

Definition

Prélèvements

Amniocentesis is a test to study amniotic fluid that surrounds the baby. Amniotic fluid contains cells and other substances that can give information about baby’s health.
Amniocentesis is done by putting a needle through the belly into the uterus and then amniotic fluid is collected and examined in lab.
This procedure is realized with all conditions of sterilized environment, with ultrasound support. (to guide the needle).
Puncture is not more painful that a simple blood sampling. You will be able to go home after the amniocentesis, but a full day of rest is recommended.

Complications

Amniocentesis is done from 13 weeks of gestation.
Despite a specific procedure including high security process, miscarriage risk is from 0,5% to 1%.
This miscarriage risk is higher during 8 to 10 days after the amniocentesis. Symptoms of miscarriage include severe cramps, abdominal pain, fever, fluid discharge, bleeding. If you experience one of these symptoms, contact your obstetric doctor or health care center right away.
It may happen that miscarriage is silent, with none of the above symptoms.

Miscarriage risk depends on your health, your medical background or a treatment taken before amniocentesis. It is therefore imperative that you inform your doctor of your medical history (personal ones and family ones) and all medical treatment you are taking.
Some very rare cases of severe infections for the mother and the baby have been noticed.

In practice

There is no need to come with empty stomach for this exam. You must have with you your blood group card. For Rh-negative blood, a supplementary injection will be done to prevent any reaction of your body against red blood cells of your baby.
Your doctor will give you results of the amniocentesis between 1 to 5 weeks after the exam, depending on the analysis realized.

Chorionic Villus Sampling (CVS)

Chorionic Villus Sampling is a test done during early pregnancy (from 9 weeks of gestation).
Chorionic Villi are tiny finger-shaped growths found in the placenta. During CVS, a sample of the chorionic villi is taken for biopsy and analyzed. CVS is used to find genetic disorders, birth defects, as for amniocentesis.

Distinctive characteristics:

  • Realized at an earlier stage of pregnancy
  • Miscarriage risk is the same
  • Results are given within 48 to 72 hours. A 2nd exam may be needed, from the same sample (after cell culture of 3 to 4 weeks).

Last update: 10/2/2013