US president Barack Obama speaks as vice-president Joe Biden,  US Secretary of Health and Human Services Sylvia Burwell, National Institute of Allergy and Infectious Diseases director Anthony Fauci and members of the press listen after a meeting about the Zika virus in the Oval Office of the White House. Photograph: Brendan Smialowski/AFP/Getty Images

Doctors are monitoring 279 pregnant women with confirmed or suspected Zika virus infections in the US and its territories, federal health officials sa(...)