Abnormal results on noninvasive, prenatal genetic tests may uncover maternal cancers apart from the problem with the fetus.
In a recent study, 10 women had abnormal findings on a noninvasive prenatal test. A more invasive follow-up test found normal results for the fetus, but the test also revealed cancer in the mother.
"If the test comes back abnormal, the patient should not panic. It doesn't necessarily mean anything is wrong with the fetus," said study researcher Dr. Diana Bianchi, executive director of the Mother Infant Research Institute at Tufts Medical Center in Boston.
The findings point to the need to do further tests if the noninvasive blood test comes back positive. The chances of this happening are low, she said, but it's crucial to consider the possibility.
"Cancer is not that common in pregnant women. It [affects] about one in 1,000," said Bianchi.
Noninvasive prenatal testing (NIPT) is a screening test that analyzes the mother's blood, which contains fragments of both placental and maternal DNA. The test looks for certain fetal abnormalities associated with specific chromosomes that may indicate birth defects or a condition, such as Down's syndrome.
NIPT can be done as early as the 10th week of pregnancy and is typically offered to women with high-risk pregnancies, such as older mothers or those with a family history of certain birth defects.