From: Rabbi Moshe Sofer
To: Unknown recipient
The Chasam Sofer resolves an apparent contradiction between YD 267 (which denies kofer collection to a half-freed maidservant for lack of heirs) and EH 44 (which validates kiddushin for her) by explaining that although kiddushin takes effect, the slave-element so weakens it that her offspring lack the yichus required for inheritance. He adds that practically, if men transgress with her the master is compelled to free her, eliminating the half-kenas interest simultaneously.
Source: Shu"t Chasam Sofer EH II §151