Tests

Laboratory tests

Blood and urine screenings are carried out at regular intervals over the course of a pregnancy, in order to:

• confirm that you are pregnant: measure the level of hCG (Human Chorionic Gonadotropin) in your blood;
• screen for diseases such as syphilis, toxoplasmosis, the AIDS virus, hepatitis B, hepatitis C, a urinary tract infection, the presence of protein in the urine (albumin), etc.;
• check the number of red blood cells, white blood cells, blood platelets, iron levels, blood sugar levels, etc.

Toxoplasmosis tests

Toxoplasmosis is a disease caused by a parasite which can lead to serious malformations of the foetus, or even foetal death. Any pregnant woman who does not have antibodies to protect against toxoplasmosis will be regularly tested for the disease throughout her pregnancy.

Triple test

The 'triple screen', or the 'T21' test, screens for the risk of trisomy 21, also known as Down's syndrome.

This is a non-compulsory blood test, carried out between the 14th and 18th weeks of pregnancy.

A positive result is not a definitive indication that the child has Down's syndrome, but indicates that amniocentesis should be carried out, to confirm or rule out a diagnosis of trisomy 21.

Similarly, a negative result does not guarantee that the child will not be trisomic, but expresses a very low level of risk.

An ultrasound examination of the nuchal translucency between the 11th and 12th weeks of pregnancy (first ultrasound) is another indicator to look at if trisomy 21 is suspected.

Amniocentesis

Amniocentesis is a medical test during which a needle is inserted through the woman's abdomen to sample a small amount of the amniotic fluid. This is the fluid surrounding the foetus. It contains foetal cells, which can subsequently be analysed.

Amniocentesis is performed between the 14th and 20th week of amenorrhoea. It can be used to detect Down's syndrome, but also other chromosomal anomalies such as spina bifida.

Amniocentesis is not a risk-free procedure. For this reason, amniocentesis is not a test that is routinely carried out on all pregnant women.

Amniocentesis may:

• bring on contractions,
• cause the amniotic fluid to leak,
• lead to foetal death,
• result in the loss of the pregnancy.

Amniocentesis is only offered to women at higher levels of risk:

• women aged 35 or over (higher risk of Down's syndrome),
• women whose triple screen gives a positive result,
• women with a high-risk pregnancy for other reasons.