From: Rabbi Moshe Sofer
To: Rabbi Aryeh Yehuda Leib Toiber
A husband who accused his wife of adultery during divorce proceedings retracted the claims and offered an amtala that he fabricated the accusations to avoid paying the kesubah. The Chasam Sofer rules the wife is clearly permitted to remain married to her husband on multiple grounds: the amtala is credible given she was demanding a get, the cherem of Rabbeinu Gershom prevents a forced self-binding prohibition, and even if the pregnancy claim stands, she may have been raped which does not forbid a Yisrael's wife. The status of the child remains an open question requiring further analysis.
Source: Shu"t Chasam Sofer EH II §111