The WHO is now telling women who have been exposed to Zika to wait twice as long before getting pregnant

The World Health Organization just issued new guidelines that increase the length of time couples who have traveled to areas affected by the Zika virus should abstain from unprotected sex.

The WHO now recommends that couples, or women planning a pregnancy, wait at least eight weeks to have unprotected sex after returning from a region where the virus is present. It previously had suggested that women wait only four weeks before trying to get pregnant.

The recommendations stem from new evidence that Zika can remain present in body fluids for longer than previously thought, the Guardian reported.

The guidelines are for men and women who haven't had any symptoms of the virus, but may have potentially been exposed. However, in instances where the male partner has exhibited Zika symptoms, the WHO recommends that the couple either abstain from sex, or practice safe sex, for six months.

"The guidance is to delay or consider delaying pregnancy, certainly recognizing that this is tough for some populations," a WHO spokesman said.

Zika is known to cause a birth defect called microcephaly - in which babies are born with abnormally small heads and underdeveloped brains - and has also been linked to Guillain-Barré syndrome, which causes temporary paralysis.

The virus can be transmitted sexually from symptomatic men to his sexual partners, though it is not yet known whether the virus can be transmitted sexually from asymptomatic men or females, the guidelines said.