Roughly 10 percent of children born in the United States in 2016 were diagnosed with visible birth defects.

A report from the Centers for Disease Control and Prevention reveals that 15 percent of pregnant women who became infected with Zika virus during their first trimester gave birth to babies with visible birth defects.

Zika virus, which spreads through the bite of an infected Aedes mosquito, can be passed onto a fetus during pregnancy. It is known to cause birth defects in newborn children.

These birth defects include microcephaly and/or brain abnormalities, dysfunction of the central nervous system, eye abnormalities, and other brain deformations.

The study was published on April 4 and was a joint effort of the CDC, tribal, state, local, and territorial state health departments. The study aimed to determine the spread of Zika virus in the United States.

US Grapples With Zika Virus

To determine the consequences of Zika virus on pregnant women, the CDC established the USZPR or the U.S. Zika Pregnancy Registry in early 2016.

The USZPR was founded to monitor infants born to women with laboratory evidence of Zika virus infection while they were pregnant. The report was made after a thorough analysis of completed pregnancies registered in the USZPR from the District of Columbia and 50 other states in the country from Jan. 15 to Dec. 27, 2016.

The list of completed pregnancies includes pregnancy losses and live births, irrespective of the gestational age.

Key Findings Of The Study

It was found that in 44 states, nearly 1,300 pregnancies were reported to the USZPR with possibility of Zika virus infection. Approximately one out of 10 women infected with the Zika virus either had a fetus or a baby with Zika virus-related birth defects.

"Birth defects were reported in 15 percent of fetuses/infants of completed pregnancies with confirmed Zika virus infection in the first trimester," wrote the researchers.

It was also discovered that only 25 percent of live infants born to mothers with possible Zika virus infection underwent postnatal neuroimaging.

Zika Poses A Continuous Threat

The new estimates prove that Zika is not confined to the borders of Brazil and has substantially spread to the United States.

"Although Zika may seem like last year's problem, or an issue confined to Brazil, there have been more than 1,600 cases in pregnant women reported here in the [United States]," said Dr. Anne Schuchat, acting CDC director.

Margaret Honein, the lead author of this study, states that lack of thorough knowledge in the domain of Zika virus initially led doctors and health officials to undermine the epidemic. Doctors are still unsure when it comes to Zika virus' effects and symptoms, especially in infants.

Further research has shown that a baby infected with Zika virus from the pregnant mother can appear healthy at birth. However, the infant may develop brain abnormalities at the later stages of his or her life.

"It's really key for these babies to have a head ultrasound or CT scan to look for abnormalities that may not be apparent at birth," stressed Honein.

The study has been published in the CDC's Morbidity and Mortality Weekly Report.