Prenatal Diagnosis

It is already possible to diagnose many diseases in newborn babies and even in the fetal phase.

If the fetus has a serious genetic disease, the couple can prepare to raise a child with a certain anomaly, since abortion is not allowed in Brazil because of fetal anomalies.


Amniotic cavity puncture through the abdominal wall, performed on a pregnant woman; allows the withdrawal of a certain amount of amniotic fluid for analysis purposes.

Early amniocentesis, practiced between 16th and 18th week of gestation, allows the diagnosis of fetal anomalies; It is also possible to detect if the child has mongolism, anencephaly or other genetic abnormality. Late amniocentesis, performed in the third trimester of pregnancy, serves to show if there is chronic fetal distress.

Villorionic sampling allows the diagnosis of hereditary diseases between the eighth and tenth weeks of pregnancy, thus earlier than amniocentesis. With the aid of a long puncture instrument introduced through the vagina into the uterus, a small portion of the projections and folds (villi) of the membrane covering the embryo, the chorion, is removed. The cells thus obtained can be cultured for a time in nutrient medium or used directly for the type of analysis to be performed.

The removal of chorionic villus samples causes abortion in 1% of cases. Therefore, this diagnosis is only used in cases where the risk of the fetus being affected by genetic diseases is very high, which justifies its early detection for possible therapeutic abortion (which must be judged by the court).