Health authorities in Tonga say advice for women in the kingdom to delay any planned pregnancy is indefinite at this stage.
Tonga reported 549 suspected cases and seven confirmed cases of the Zaikai virus this year and the instances of the disease in Brazil had been potentially linked to birth defects there.
Chief Medical Officer Reynold 'Ofanoa said they had encouraged all people but especially pregnant women to take precautions to avoid mosquitoes, which carry the virus.
Dr 'Ofanoa said they had also advised women to delay any plans to get pregnant.
"We haven't set a timeline because we are not really sure how the outbreak will unfold during the next few months but we gave them a general advice that they should delay until the outbreak is over or it comes under control."
The US Center for Disease Control and Prevention has advised pregnant women in American Samoa, which has four confirmed Zaikai cases, to use condoms for sexual activities or consider abstaining from sex.
This came after the CDC said the virus could also be sexually transmitted.