Prenatal Blood Tests Reveal Hidden Cancer in Mothers-to-Be
A groundbreaking study has uncovered a surprising new benefit of prenatal blood tests: detecting hidden cancers in pregnant women. Research published in the New England Journal of Medicine highlights how unusual results in cell-free DNA (cfDNA) testing, commonly used to screen for fetal chromosomal abnormalities, can also reveal signs of undiagnosed maternal cancers.
How Prenatal Tests Work
Cell-free DNA testing, also known as noninvasive prenatal testing (NIPT), involves analyzing fragments of DNA circulating in a pregnant person’s bloodstream. While primarily used to identify chromosomal disorders such as Down syndrome or to determine the baby’s sex, the test occasionally picks up DNA fragments from other sources, such as cancer cells.
This type of testing has become widespread over the last decade, offering a safe and noninvasive method for early fetal screening. However, about one in 8,000 cases yield inconclusive or unusual results that don’t fit expected patterns.
Study Findings: Hidden Cancer in Nearly Half of Cases
The National Institutes of Health (NIH) conducted an analysis involving 107 pregnant women with abnormal cfDNA test results. Among them, 52 were diagnosed with cancer—48.6% of the group. The cancers included lymphoma, breast, colorectal, pancreatic, and lung cancers.
For these women, standard diagnostic methods such as symptom evaluation or physical exams were often insufficient. Whole-body magnetic resonance imaging (MRI) proved to be the most effective diagnostic tool in confirming the presence of cancer.
The findings underscore the complexity of interpreting abnormal test results, which may not always indicate fetal issues but rather point to underlying maternal health concerns.
Real-Life Cases Highlight the Dual Purpose of Testing
One case involved a 37-year-old mother whose prenatal test suggested severe fetal abnormalities, including Patau syndrome. However, further scans revealed the fetus was healthy. After giving birth, the mother experienced pelvic pain, leading to a diagnosis of metastatic small cell carcinoma. Tragically, her prenatal test had inadvertently flagged her aggressive cancer, which was later found to have genetic traits consistent with the abnormal cfDNA results.
Implications for Maternal and Fetal Care
The dual utility of cfDNA testing has significant implications for healthcare providers and patients. Dr. Diana Bianchi, senior author of the NIH study, emphasized that while these findings are rare, they should heighten awareness among obstetricians about the potential for such results to reflect maternal health issues rather than fetal abnormalities.
However, experts caution against causing undue anxiety. “We don’t want to create a lot of fear,” noted Dr. Neeta Vora, a maternal-fetal medicine specialist, “but it’s crucial for healthcare providers to recognize the possibility and act accordingly.”
Next Steps in Research
The NIH’s ongoing IDENTIFY study aims to deepen understanding of cfDNA patterns that could indicate undiagnosed cancers. Researchers are exploring ways to improve the accuracy and interpretation of test results, ensuring that anomalies are promptly and correctly investigated.
The Bottom Line
While cfDNA testing is primarily used for fetal screening, this study highlights its potential to detect hidden cancers in pregnant women. For those with unusual results, further testing can lead to early cancer diagnosis and treatment, potentially saving lives. This discovery underscores the importance of advancing technology in prenatal care—not only for the health of the baby but also for the mother.
References
- Abnormal prenatal blood test results could indicate hidden maternal cancers –NIH – (Accessed on Dec 06, 2024)
- Prenatal blood test can sometimes hint at cancer in moms-to-be – AP News – (Accessed on Dec 06, 2024)
- Unusual genetic results in prenatal tests can also flag cancers—in the mom – Science – (Accessed on Dec 06, 2024)
- Prenatal test accidentally picks up cancer in 50% of those with wonky results – ars Technica – (Accessed on Dec 06, 2024)
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