Definitions by Carl Sagan

ultrasounds 

U.L.T.R.A.S.O.U.N.D.S. - an acronym for Unknown Lifeform TRacking System for the Organization and Utilization of Newly Discovered Species. This device is used to track alien invasions into our universe. see babies a.k.a aliens

The ultrasounds showed the use of the mother as a knowing host for the alien invasion

ultrasounds by Carl Sagan September 27, 2004