Ultrasound Used to Determine Prenatal Brain Damage Caused by the Zika Virus

The Zika Virus made headlines in 2015 and 2016 when outbreaks spread throughout Brazil and neighboring countries, numerous Caribbean islands, parts of North America, and even several islands in the Pacific.

In February 2016, 1 month after the Zika virus was confirmed as an epidemic, it was beginning to become apparent that this virus, in addition to causing Dengue fever-like symptoms (fever, rash, joint pain), was also triggering birth defects. An article in The Lancet: Child & Adolescent Health discusses how researchers in Martinique evaluated the use of ultrasound in the identification of the brain damage connected with Zika Virus Syndrome.

Because ultrasound technology uses sound waves to generate an image, it’s safe for examining particular parts of a baby still in the womb, including the brain and hips. The Zika virus is spread by several species of the Aedes mosquito, a family of mosquito that can also carry Dengue Fever, Yellow Fever, and Chikungunya, amongst others. The Zika virus causes multiple congenital (present at birth) defects. The most obvious defect caused by Zika is Microcephaly, when a baby’s head is considerably smaller than normal. The study also set out to pinpoint other notable physical defects as well, using ultrasound.

Fourteen pregnant women who had confirmed Zika virus during their first trimester or early second trimester and had abnormal fetal findings were examined. In total, 31 ultrasound images were assessed for fetal irregularities of the brain at different time points during the pregnancy. The trend was that as the pregnancy progressed, the fetal anomalies became more numerous and severe. These included enlarged cerebral ventricles observed in 10 of the fetuses. This is also commonly known as ventriculomegaly or hydrocephalus, an ailment that can hinder proper brain development. General deterioration of the brain’s cortex, the tissue that comprises the large outer portion of the brain, was identified in 11 of the fetuses. Deposits of calcium were seen in 10 of the fetuses. Finally, defects in the corpus callosum, the large bundle of neurons that joins the 2 halves of the brain, was found in 10 of the fetuses. Of note, only 9 of the fetuses displayed microcephaly suggesting it may be more beneficial to use the other structural abnormalities to identify birth defects caused by Zika virus.

The researchers who carried out this study discovered that ultrasound is a sufficient tool to screen for Zika virus in pregnant women who have been possibly exposed. They also suggested that scanning be done at 22-26 weeks of pregnancy and should focus on the aforementioned structural defects. This study was much needed in the face of something as potentially damaging to the human population as Zika virus, and was successful in developing a competent screening strategy to recognize fetal anomalies early on. Impending research should focus on preventing the spread of Zika, as it has already proven it can spread quickly.

The full study can be found at Science Direct.

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