16:34 02 March 2016
Public Health England, which previously encouraged expectant mothers to reconsider travel plans to areas with Zika outbreaks, is now strongly advising pregnant women to postpone such travel plans.
In recent months, Zika has been spreading across much of the Americas and in February, the World Health Organisation has declared the situation a global public health emergency.
Prof Paul Cosford from Public Health England said: "As our knowledge of the Zika virus, and the evidence linking microcephaly to Zika infection, becomes clearer a more precautionary approach is warranted. This advice will be kept under review and updated as more information becomes available.
"We expect to see small numbers of Zika virus infections in travellers returning to the UK, but the risk to the wider population is negligible as the mosquito vector is not found in the UK."
Meanwhile, a spokesman for ABTA, the travel association, said pregnant women should seek medical advice from their GP if they plan to travel to affected countries.
"Where it is necessary to change or cancel their holiday arrangements in light of the NaTHNaC advice, they should request that their GP provides them with a medical certificate in order to assist them with any possible insurance claim.
"Travel companies will try and be as flexible as possible with pregnant customers who had already booked before the advice changed, and many are offering customers the option to amend their holiday to an alternative destination free of charge."