Pregnant women have been advised to avoid travelling to Brazil and 14 other countries following an outbreak of Zika virus, which has been linked to birth defects.
A Zika virus outbreak in Brazil is suspected to be related to a large increase in the number of babies born with microcephaly - a genetic abnormality that stops the foetus' brain from developing properly and causes babies to be born with an unusually small head.
"Reconsider travel to areas where Zika virus (ZIKV) outbreaks are currently reported as further evidence for a possible link between ZIKV infection and congenital malformations emerges."
Elison, 10, nurses his 2-month-old brother Jose Wesley who was born with microcephaly following an outbreak of Zika virus in Brazil.
The Foreign Office offers the same advice for women travelling to the following 14 countries where there have been confirmed cases of locally acquired Zika virus - Mexico, Guatemala, El Salvador, Honduros, Haiti, Panama, Ecuador, Colombia, Venezuela, Guyana, Suriname, French Guiana, Bolivia and Paraguay.
Dr Helen Webberley, GP for Oxford Online Pharmacy explained why it's important for pregnant women to carefully consider any plans to travel to these countries.
"In the majority of people the Zika virus causes no symptoms, although a few may have a couple of days of flu-like symptoms," she told HuffPost UK Parents.
"However, there is some concern emerging that there may be an increase in congenital abnormalities in areas where Zika infection outbreaks have occurred.
"If you are pregnant or planning to get pregnant then the current advice is to avoid travel to any areas where an active Zika virus is being reported or, if this is not possible, then to take extra special measures to avoid insect bites.
"A balance of risk needs to be taken here as this link between infection causing abnormalities has not been confirmed and more work needs to be done to prove any causation."
The Zika virus is transmitted via mosquitoes and cannot be caught from coming into contact with an infected person. However possible cases of sexual transmission have been reported.
There is currently no treatment or vaccine.
According to the NaTHNaC, the Department of Health’s travel advice branch, scientists are currently investigating whether a causal relationship exists between exposure to Zika virus in pregnancy and microcephaly.
A map illustrating the countries in the Americas where Zika virus outbreaks have been reported is available on the Pan American Health Organisation's website.
If you are planning on travelling to any of the infected countries, seek advice from a health professional if you have any questions or concerns.