The CDC is now advising couples trying to conceive to wait at least six months if the man was potentially exposed to Zika.
Previously, the CDC advised couples to wait at least eight weeks after last exposure to the mosquito-borne, sexually transmitted virus to try to conceive.
"The new time period for couples to wait to attempt conception when the man has possible Zika exposure but no symptoms are expected to minimize the risk of sexual transmission around the time of conception and prevent possible early fetal exposure to the Zika virus," a CDC statement reads.
Zika virus can be transmitted sexually, and has been found to stay in a man's semen for six months after symptom onset. If a pregnant woman contracts a Zika infection, it can put her fetus at risk for birth defects, such as microcephaly.
As of Sept. 28, 30 Zika cases in the U.S. are thought to have been transmitted sexually.