When You Want To Be Sure
Amniocentesis is a prenatal diagnostic procedure used to detect (or far more likely, to rule out) the presence of certain chromosomal anomalies in the fetus you are carrying. This test is performed during the second trimester of the pregnancy (between the 15th and 22nd week), generally during the 16th week. Amniocentesis is performed in two stages:

Puncture into the mother's abdomen to extract some amniotic fluid;

Laboratory culture and analysis of the chromosomes in the fetal cells present in the sample of amniotic fluid.

The procedure only takes a few minutes. The physician first locates the fetus and the placenta using ultrasound on the mother's abdomen. After having marked and cleansed the area where he/she feels will be safest for the insertion of the needle, the physician withdraws amniotic fluid.

The second stage of amniocentesis is carried out using living fetal cells contained in the amniotic fluid. After approximately one week of culture in the laboratory, these cells are harvested by the technologist and the chromosomes are analyzed in order to detect (or rule out) possible anomalies.

Amniocentesis results are ready within 7 to 12 days. This timeframe can increase when further analyses are deemed necessary in the event of rare or complex genetic diseases.

Potential risks and precautionary measures
Several studies conducted worldwide have shown that ultrasound guided amniocentesis is safe for both the mother and her baby. There is however, a 0.5 to 1% risk of maternal infection and miscarriage. It has also been proven that this risk diminishes in accordance with the physician's level of experience. At PROCREA Cliniques, our physicians perform amniocentesis on a weekly basis making them very familiar with this technique. It is recommended to avoid any form of physical exertion for 24 hours following the amniocentesis.

Who is a candidate for amniocentesis?

Any pregnant woman who, at her due date, will be 40 years of age or older*;

Any woman whose Combitest® results are high (blood tests and or fetal ultrasound);

Any woman whose ultrasound results may indicate a fetal genetic anomaly;

Any woman who has a family history or whose partner has a family history of one or more incidents of chromosomal anomalies or genetic disorders with a high recurrence risk;

It is also possible for women under the age of 40, with no history of genetic disorder to have an amniocentesis; it is a matter of personal choice. However, a medical referral is required in such a case.

*SOGC guidelines, Feb. 2007

Understanding your results

In more than 95% of cases, the results of an amniocentesis provide parents with the reassurance that their baby is not affected by a chromosomal anomaly; the results are 99% accurate. When the results are such, you will be contacted by PROCREA Cliniques directly.

However, there is a possibility that a chromosomal or genetic anomaly may be detected through the amniocentesis. In such a case, your treating physician will be the first to be notified by phone, and he/she will schedule an appointment to meet with you and your spouse as soon as possible. Receiving such news is often quite distressing for couples, this is why it is essential to be surrounded by skilled professionals trained to counsel them and help guide them through the decision-making process of whether or not to continue the pregnancy. Should you feel the need, do not hesitate to reach us to make an appointment with a genetic counselor.