If you are pregnant (or think you might be) think twice before hopping on a plane to the Caribbean or Latin America. The Centers for Disease Control and Prevention (CDC) has issued a travel health alert for Brazil and 21 other countries, including Mexico and Puerto Rico, where the Zika virus is proliferating. Transmitted by mosquitoes, the virus has been linked to a birth defect called microcephaly, which leaves children with abnormally small heads and brain damage. The number of cases of microcephaly in Brazil has risen dramatically in the last several months to nearly 4,000. If you are pregnant and have recently visited any of the countries where there is a travel advisory, the CDC recommends that you get tested for the virus. See cdc.gov/media/releases/2016/s0315-zika-virus-travel.html for a complete list of affected countries.