A new study suggests noninvasive prenatal screening can detect cytomegalovirus, a common cause of permanent hearing loss in newborns.
A study published in the Association for Diagnostics & Laboratory Medicine’s journal Clinical Chemistry indicates that noninvasive prenatal screening (NIPS) can detect cytomegalovirus (CMV) in pregnant women, potentially identifying pregnancies at risk for transmitting the virus to the fetus. CMV is a common infection that can cause permanent hearing loss and other developmental issues in newborns.
The findings suggest that incorporating CMV detection into routine NIPS could help clinicians identify patients who may benefit from antiviral therapy to prevent congenital CMV.
In addition to permanent hearing loss, CMV can lead to neurodevelopmental delays in up to 20% of infants born with the infection. According to the source material, congenital CMV occurs in approximately 1 in 150 live births worldwide. Current guidelines do not typically recommend prenatal screening for CMV.
The study, led by Dr Geert A Martens from Belgium, analyzed NIPS data from 22,333 pregnancies at 12–14 weeks’ gestation. Using low-pass whole genome sequencing, a cost-effective NIPS method, researchers searched for cell-free DNA from CMV in maternal blood samples.
The analysis found CMV DNA in 2.1% (462) of the pregnancies. The researchers reported that the amount of viral DNA detected via NIPS demonstrated good diagnostic accuracy for both maternal and newborn CMV infections when compared to confirmation via antibody testing and a systematic newborn screening program. The risk for congenital CMV was highest in pregnancies where the most CMV DNA was detected.
This identification is clinically relevant as research has shown the antiviral drug valacyclovir can reduce CMV transmission from mother to fetus by more than 70% when administered in the first trimester. While not formally approved by the Food and Drug Administration for this purpose, the drug is prescribed by many doctors for pregnant patients with a known CMV infection.
“Given its low cost and high throughput, [the integration of CMV DNA testing] into routine aneuploidy screening is a powerful complement to serology, poised to improve the identification of pregnancies that may benefit from antiviral therapy to prevent cCMV,” the authors wrote.
