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Frequently asked questions about prenatal genetic diagnostic

Which factors would lead a couple to schedule a prenatal genetic consultation?

In LabGenetics we act as consultant to all couples who request information, although situations that preferably lead to recommend an prenatal genetic research could be summarized in the following:

• Advanced maternal age (30-35 years old upwards)
• Advanced paternal age (50 years old upwards)
• Positive chromosome-pathologies Biochemistry research (risk higher than 1/270)
• Previous child with Down Syndrome or other chromosomal aberrations.
• Chromosomical alterations in one member of the couple
• Family history of mental impairment, chromosomal aberrations or malformations.
• Antecedents of hereditary diseases
• Sterility problems or recurrent miscarriages
• Suspicious echograph results with chromosomal aberrations or malformations.
• Exposure to several harmful agents: contraceptives, medicines, radiation, etc
• Several obstetrical situations: absence or excess of amniotic liquid in the fetus, fetal growth delay, anomalies in fetus cardiac rhythm, etc.

After which week of gestation can a prenatal genetic diagnosis be done? Which methods are used to obtain fetus cells?

An prenatal genetic diagnosis can be done at different periods of gestation, depending on the method used to obtain fetus cells:

1. chorionic biopsy: This involves obtaining the chorionic villus from the vagina (transcervical) or from the abdomen (transabdominal). It is usually done between the 10th and 12th week of gestation.

2. Amniocentesis: This involves the extraction of amniotic liquid using transabdominal punction. It is usually done between 14th and 16th week of gestation.

3. Funiculocentesis or cordocentesis: It consists in extracting fetus blood using a direct umbilical cord puncture. It is usually done after 18th weeks of gestation.

Is a previous culture cell necessary in order to carry out a prenatal genetic diagnosis?

No. In LabGenetics we use the most advanced methodology to offer prenatal genetic diagnosis without the need for a previous culture cell of amniocyte. This allows us to give the test results in a short period of time: 24 hours to detect aneuploidies via the QF-PCR and less than 1 week for the rest of genetic diseases. Nonetheless, for cytogenetics research a previous culture cell is necessary to obtain the complete cariotype.

Is it possible to diagnose Down syndrome in the fetus within just 24 hours?

Yes. Using the QF-PCR technique, LabGenetics can detect, within just 24 hours, the most common numerical chromosomical disorders or aneuploidies which are the cause of syndromes such as Down, Patau, Turner, Klinefelter, etc. This diagnosis detects approximately 70 to 80% of the chromosomal aberrations that are the cause of congenital defects during pregnancy, even if this percentage is higher (99%) in low risk pregnancy.