One who prays alone behind the row: Abu Hanifah said his prayer suffices him

It is narrated from Sayyiduna Abdullah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) had a man and his wife perform li'an, and said: "It may be that this woman gives birth to a black, curly-haired child." And this woman gave birth to a black, curly-haired child.

Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that the Prophet (peace and blessings be upon him) had li'an performed on the basis of pregnancy.

It is reported from al-Sha'bi, as a fatwa concerning a man who declares himself clear of his wife's pregnancy, that such a man shall perform li'an with the woman. It is mentioned that the view of (Imam) Abu Hanifah is: He did not hold that li'an is performed on the basis of (denial of) pregnancy.