From: Rabbi Moshe Sofer
To: Rabbi Itzik
The Chasam Sofer rules that an adult consenting woman has forfeited claims for shame and blemish; the father's obligation to pay nursing costs cannot be enforced by oath since paternity is denied and the obligation is one of tzedakah rather than debt; and regarding the alleged vow to marry, the woman may require a shevuas heses. If the man retracts his denial under threat of the oath, his retraction is valid as an amasla, since fear of a false oath — unlike fear of physical punishment — ensures that any admission is truthful.
Source: Shu"t Chasam Sofer EH II §160