Pregnancy

Prenatal diagnosis


Discoveries in genetics, progress in biology and medical imaging allow a better knowledge of the unborn child. Fetal medicine has completely revolutionized the monitoring of pregnancy and has pushed the limits of certain pathologies, especially through prenatal diagnosis or DPN.

Prenatal screening and diagnosis: same fight?

  • We must not confuse these two notions that correspond to two different approaches. Prenatal screening is a non-compulsory exam, pregnant women to calculate their risk of having a fetus carrier of a genetic anomaly, such as trisomy 21 for example. This test is intended for a population with a high risk of having a child suffering from this anomaly without making a diagnosis. If there is a proven risk, a prenatal diagnosis (PND) will be proposed. Not compulsory, this examination consists in the analysis of the chromosomes of the fetus starting from examinations of investigations - amniocentesis or choriocentesis. According to the age of the pregnancy, one will take by puncture is amniotic liquid or some cells of the chorion (future placenta), in order to be able to establish if the fetus is carrying or not the anomaly.

Who is the DPN for?

  • Prenatal diagnosis (PND) is a specific approach offered to couples who are at risk of giving birth to a child with a condition of a particular gravity and incurable at the time of diagnosis, as may be the case for Duchenne muscular dystrophy, cystic fibrosis ...
  • PND can also be proposed after discovery of call signs during conventional biological or ultrasound monitoring of pregnancy, or when the couple is at risk, given their history, to conceive a child with a genetic disorder.

  • Today in France, this approach concerns less than 2% of couples each year.

How does a prenatal diagnosis take place?

  • The approach of prenatal diagnosis follows a specific protocol. The couple is received in genetics department (most often in large hospitals). This consultation will make it possible to define, based on the family tree and the family and personal antecedents of the parents, the risk of occurrence of a possible genetic disorder. The prenatal diagnosis can then be proposed to the pregnant woman and will be realized as quickly as possible.

DPN also, in some other cases

  • A DPN can also be offered after discovery of call signs, as high serum markers of Trisomy 21 during biological monitoring or disturbing measures during conventional ultrasound monitoring of pregnancy, one or when the couple presents a risk, in view of its antecedents, to conceive a child with a condition genetic.

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