Non-invasive prenatal testing (NIPT) is likely to become a primary screening method for chromosomal abnormalities in pregnancy in the future, reducing invasive testing and the associated risks, according to a scientific impact paper published by the Royal College of Obstetricians and Gynaecologists (RCOG).
The document looks at the issues surrounding the technology, including what it is currently used for and comparisons with invasive testing.
Fetal genetic testing has, until recently, needed invasive diagnostic procedures (amniocentesis or chorionic villus sampling) which carries with it a risk of miscarriage. However, since 1997, the presence of cell-free fetal DNA (cffDNA), which comes from the placenta and can be detected from the first trimester of pregnancy onwards, has changed practice and is used for detecting certain conditions.
The document explores the use of cffDNA for chromosome testing and possible sources of error in results from the technology, looking at the difference between this technology and current practice and the advantages and disadvantages of cffDNA.
Advantages include the possibility of detecting, without risk to the pregnancy, diseases that may have potentially serious consequences and secondly it is much more accurate than any of the previous screening tests.
However, the disadvantage is that pregnant women may occasionally be informed of findings of uncertain significance, such as when there is a discrepancy between the chromosomal makeup of the cells in the placenta and the cells in the baby, known as placental mosaicism. This can result in a healthy pregnancy, however, in some pregnancies it can lead to complications.
