Fetoplacental discrepancies
Mosaics limited to the placenta associated with intrauterine growth disorders
Depending on when and in which stage of embryonic development faulty chromosomal division occurs, different tissues (fetal and/or extra-fetal) are affected by it.
Types of chromosomal mosaicism
Certain chromosome anomalies result in confined placental mosaicism (CPM) which can be associated with an increased risk for altered placental function, leading to intrauterine growth restriction, fetal demise and risk for uniparental disomy (UPD).
Presence of two or more chromosomally different cell lines in both the placenta and the fetus.
Presence of two or more chromosomally different cell lines in the placenta, but not the fetus.
Presence of two or more chromosomally different cell lines in the fetus, but not in the placenta.
• Normal cells
• Cells with abnormal chromosomes
Wegner and Stumm report that in 1 – 2% of chorionic villi examined, mosaics limited to the placenta were able to be detected (Wegner und Stumm 2011). Despite a high degree of accuracy of NIPT, there will always be discordant test results.
Important for your practice: While invasive diagnostic procedures can, as a general rule, be avoided in the case of an unremarkable test result – in the context of all relevant clinical findings and after appropriate explanation provided to the pregnant woman – positive test results must be diagnostically clarified using invasive methods, according to the recommendations of professional associations.
Please note: a predictive value of 100% cannot be expected. Eurofins LifeCodexx work is state of the art in terms of science and technology. Eurofins LifeCodexx notes that a validity of 100% in the use of the PrenaTest® at the practice cannot be expected. There are risks that can never be fully excluded, no matter how meticulous the genetic analysis is. Nevertheless, all possible measures and safety precautions are undertaken to avoid these risks and other errors.