C. F. Keil and Franz Delitzsch on 2 Chronicles 13:21

2Ch 13:21 Wives and children of Abijah. His death. - 2Ch 13:21. While Jeroboam was not able to recover from the defeat he had suffered, Abijah established himself in his kingdom (יתחזּק, cf. 2Ch 12:13), and took to himself fourteen wives. The taking of these wives is not to be regarded as later in time than his establishment of his rule after the victory over Jeroboam. Since Abijah reigned only three years, he must have already had the greater number of his wives and children when he ascended the throne, as we may gather also from 2Ch 11:21-23. The ו consec. with ישּׂא serves only to connect logically the information as to his wives and children with the preceding, as the great increase of his family was a sign of Abijah’s increase in strength, while Jeroboam’s dynasty was soon extirpated.