The World Health Organization on Wednesday advised women in areas with the Zika virus, especially during pregnancy, to cover up against mosquitoes and practice safe sex but also reassured them that most would give birth to "normal infants". Acknowledging "understandable concerns" due to the risk of babies with birth defects, the WHO issued recommendations but conceded that "many unknowns" still surround the virus sweeping across the Americas, Reuters reported. The WHO declared an international health emergency 10 days ago after a spike in cases of newborns with microcephaly in Brazil linked to the mosquito-borne Zika virus, which has now been found in more than 30 countries. On Wednesday, the United Nations agency did not recommend travel restrictions, instead suggesting that women "determine the level of risk they wish to take" and consult their doctors or authorities if travelling and on return. "Whether and when to become pregnant should be a personal decision, on the basis of full information and access to affordable, quality health services," it said. Women who are pregnant or planning to become pregnant should protect themselves against bites of the Aedes mosquito that transmits Zika, the Geneva-based U.N. agency said. It advised using insect repellent with DEET; wearing light-coloured clothes that cover the body; closing doors and windows; sleeping under mosquito nets; eliminating potential mosquito breeding sites in containers that can hold even small amounts of water, such as buckets, flower pots and tyres.