Mirtha is a distinctive girls' name in United States, ranking #16061 in 1999 with 5 recorded births. The name reached its all-time peak in 2001 with 14 births ranking #7609. Since 1996, the popularity has decreased by 54.5%. In 1999, approximately 1 in every 354,756 girls born was named Mirtha. FALLING Recent data shows the name is currently falling.