Dr. Stephens

Dr. Stephens (first name unknown) is a character first mentioned in the first episode of The Walking Dead. He is the doctor for the Grimes family before the outbreak started.

Cynthiana, Kentucky
Before the outbreak, Dr. Stephens was a doctor in Cynthiana, Kentucky. He was likely friends with the Grimes family. When Carl Grimes was born, Dr. Stephens delivered him.

Post-Apocalypse
Since the beginning of the outbreak, Dr. Stephens' status is unknown. While Rick Grimes was on his way to Atlanta, he tells his newly found horse about the day Carl was born, and that Lambert called him and told him to meet the Grimes family at the hospital.

Trivia

 * Robert Kirkman stated that Dr. Stephens is the name of his personal doctor.