British couples have been advised to stop trying for a baby for up to six months if a partner has returned from one of 23 countries hit by the Zika virus.
Public Health England said all men should use condoms for 28 days after coming home from countries such as Brazil and Mexico if their partner was at risk of pregnancy, or already pregnant.
Men who had suffered an unexplained fever while travelling, or been diagnosed with the virus, should avoid unprotected sex, or trying for a child for six months. Women have already been advised to avoid travelling to infected countries if they might be pregnant or are trying for a child.
The virus has already caused nearly 4000 malformed babies in the Americas and the World Health Organisation says the disease is spreading so quickly four million people could be infected by the end of the year.