157 Pregnant Women In U.S. Show 'Laboratory Evidence' Of Possible Zika, CDC Says

The Centers for Disease Control and Prevention said Friday that it is monitoring 157 pregnant women in the United States "with laboratory evidence of possible Zika virus."

Scientists are still learning about Zika, the virus that spreads through mosquito bites and sexual contact and can cause birth defects in babies of infected women.

Research has shown pregnant women may be infected without showing any symptoms, according to the CDC. In some cases, the CDC said, these women delivered babies that had birth defects related to the virus.

So the CDC is changing the way it tallies Zika cases for pregnant women.

Previously, the center was counting only the number of women who had both laboratory and symptomatic evidence.

Now, the CDC will report, "pregnant women who have any laboratory evidence of possible Zika virus infection."

In addition to the 157 of those women in the United States, 122 pregnant women fall under the new definition in U.S. territories such as Puerto Rico and the Virgin Islands.

Patch has reached out to the CDC for more information and clarity, and we'll let you know when we hear back.

This is a developing story and will be updated.