The U.S. Centers for Disease Control is now saying women diagnosed with the Zika virus should wait at least eight weeks before attempting to get pregnant.

Men should wait at least six months after symptoms of the virus first appear before having unprotected sex, the CDC also said.

The new recommendations, published Friday, were released amid “mounting evidence” supporting a link between Zika and microcephaly, a birth defect that results in an abnormally small head and incomplete brain development.

“In making these recommendations, we considered the longest known risk period for these categories. We then allowed for three times the known period of time,” the health agency wrote on their website.

They also recommend men and women who might have been exposed to the virus – either through travel or sexual contact – wait at least eight weeks before trying to get pregnant, even if there are no symptoms present.

Preventing sexual transmission

The CDC also updated its recommendations for preventing sexual transmission of the virus.

Men who have Zika or its symptoms should “consider using condoms or not having sex for at least six months after symptoms begin,” they said.

For men who have travelled in an area with active transmission without developing symptoms, condoms should still be worn for at least eight weeks.

Their recommendations for men who have been exposed to the virus and who have a pregnant partner have remained the same, the group said.

“CDC recommends that men with a pregnant partner should use condoms every time they have sex or not have sex for the duration of the pregnancy.”