Michael Lever, 43, attacked Caroline Lever when she was pregnant with their second child and strangled her over a table.
The assault was seen by Mrs Lever's son, Patrick George, who thought his mum was going to be killed.
Lever also slapped Mr George for taking a book without permission and threw a can of beer at his daughter after an argument.
He denied the charges but a jury at Glasgow Sheriff Court found him guilt of assaulting Mrs Lever at hospital accommodation at Law Hospital, Carluke.
Sheriff Sam Cathcart deferred sentence until next month and Lever was released on bail.