-LOW RISK of the chromosomal disease

The risk of the fetus having Down, Edwards, Patau, Turner, or DiGeorge syndrome is very low. Abnormalities in other chromosomes were also not detected. Since NIPTIFY is not a diagnostic test, false-negative or false-positive results are still possible. The NIPTIFY test cannot detect chromosomal mosaicism or rare monogenic diseases. In addition, a low chromosomal risk score does not indicate other abnormalities in fetal development detected by ultrasound (for example, brain or heart malformations, spinal malformations, or developmental disorders).

-HIGH RISK of the chromosomal disease

The fetus has a high risk for Down, Edwards, Patau, Turner, DiGeorge, or other incidental findings. An incidental finding can be a microdeletion or an incorrect copy number of any other chromosome, including sex chromosomes. As the NIPTIFY is a screening test, the pregnancy should not be terminated based on this result only. An invasive diagnostic test such as amniocentesis should be considered to confirm the high risk of chromosomal disease. In case of a high-risk incidental finding, the doctor or a medical geneticist will decide the necessity for follow-up analysis.

-FETAL SEX

NIPTIFY detects fetal chromosomal sex based on DNA. If a Y-chromosome is detected in the maternal blood, there is a boy. If there are no signs of a Y-chromosome, there is a girl. In rare cases (<0.2%), the fetal chromosomal sex can not be reliably determined. The reason for such cases can be a vanishing twin, where a girl fetus is in good shape, but the deceased boy’s fetal Y-chromosome traces are still detectable in the mother's blood.

-The risk of chromosomal disease cannot be determined

The chromosomal disease risk assessment failed. The result does not mean any elevated risks. A technical failure in blood sample transportation or laboratory processes may cause the failure. In case of a non-informative result, the NIPTIFY laboratory provides a retest for the patient. One retest is free for the patient.

Incidental findings

Incidental findings can significantly affect maternal or fetal health and the functioning of the placenta until the end of pregnancy. Every incidental finding requires an individual approach and counseling. In rare cases, NIPTIFY can detect maternal chromosomal anomalies, which can indicate an existence of a tumor.

There is a high probability that the reported incidental finding occurs only in the placenta, and the fetus is healthy. In those cases, it only affects the course of pregnancy. For example, placental trisomy 16 can be accompanied by a developmental disorder of the placenta, which can lead to fetal growth restriction. Such pregnancies must be monitored more thoroughly to minimize the health risks for the mother and the fetus. If trisomy 16 is confirmed by a diagnostic test (amniocentesis) in a fetus, the pregnancy will likely end with a miscarriage. 

If an incidental finding occurs in clinically relevant microdeletion regions, it is recommended to confirm the result by DNA-based diagnostic analysis (amniocentesis).

Why NIPTIFY fails sometimes?

In rare cases, NIPTIFY Focus Plus cannot determine the risk of chromosomal diseases. Our prognosis shows this occurs in less than 0.1% of all patients after retesting. The reason for such cases is a high standard deviation in the results or low fetal cell-free DNA fraction in maternal blood. A low fetal fraction does not indicate a higher risk of chromosomal disease.

The low fetal DNA fraction can be caused by high maternal body mass index (BMI higher than 30). Premature testing, asymptomatic viral infections, or other biological and technical factors can cause low fetal DNA fraction. Fetal cell-free DNA fraction increases as the pregnancy progress and does not depend on the volume of the blood sample. In case of a low fetal fraction, we recommend giving another blood sample (retest), which is free for the patient.