Genetic screening and cancer in pregnancy
Cryos International presents a case study, in which a mother’s undiscovered cancer diagnosis was detected by a NIPT (Non-Invasive Prenatal Test) screening. Unfortunately, the true cause of the positive test result wasn’t properly determined before it was too late.
The first line of tests when screening for a healthy pregnancy is kept non-invasive and stress-free for the patient, consisting mainly of blood tests and ultrasound. More investigative, but also riskier and more invasive, tests are postponed until concern is warranted based on the results of the first line of tests. However, blood tests require additional caution when interpreting their results. In several cases, screening for genetic anomalies in the fetus arise from cancer or other illnesses within the mother.
Cell exchange during pregnancy
How is it possible to detect sickness within the mother when the test is focused on the child? The blood of the mother and child is intricately connected. The placenta delivers oxygen and food to the fetus and removes waste products for the mother for her to expel, yet this is but a fraction of what is exchanged. Just two weeks after fertilization whole cells and other genetic material begin to travel between them. These cells can remain for years after birth.
Prenatal testing
The exchange of genetic material allows doctors to investigate the genetic health of a fetus by taking a blood test from the mother. Such tests usually investigate trisomy. Trisomy causes an overexpression of the genes present because of the extra chromosome, and most fetuses with trisomy do not develop beyond the first few weeks after fertilization.
However, cancer cells can also develop trisomy. Testing does not automatically distinguish between where a sick cell comes from. Instead, doctors commonly assume that mothers are healthy, and that any anomalies come from the fetus inside her. This can be dangerous for both mother and child, as a positive cancer diagnose risks being dismissed as a sick baby.
The abnormal result
What should be done after a prenatal genetic screening with an inconclusive result? As a health professional it’s important to evaluate the analysis and maybe do further analysis. This helps the healthcare professionals conclude whether they are dealing with a sick child or parent. Deciding the cause of trisomy is highly important and can potentially be lifesaving for both mother and child.