As part of the response to the Zika outbreak, CDC, in collaboration with state, local, tribal, and territorial health departments, established a pregnancy registry for comprehensive monitoring of pregnancy and infant outcomes following possible Zika virus infection. The registry is an active surveillance system of pregnant women with laboratory evidence of possible Zika virus infection in the 50 US states and DC, and in the US territories. On May 20, 2016, CDC released detailed information about the registry and will initiate weekly reporting of the number of pregnant women followed in the registry.