From: Rabbi Moshe Sofer
To: Rabbi Hershel
The Chasam Sofer disagrees with the Dagul MeRevavah and rules that a father may perform pidyon haben himself from a distance, relying on the majority presumption that most women bear viable children. He supports this with his own teacher R' Nasan Adler's accepted practice, and argues further that performing the mitzvah personally is superior to appointing an agent.
Source: Shu"t Chasam Sofer YD §294