Vicitravīrya died of tuberculosis, and his wives, Ambikā and Ambālikā, had no issue. Therefore, after Vicitravīrya’s death, his mother, Satyavatī, who was also the mother of Vyāsadeva, asked Vyāsadeva to beget children through the wives of Vicitravīrya. In those days, the brother of the husband could beget children through the womb of his sister-in-law. This was known as devareṇa sutotpatti. If the husband was somehow unable to beget children, his brother could do so through the womb of his sister-in-law. This devareṇa sutotpatti and the sacrifices of aśvamedha and gomedha are forbidden in the Age of Kali.

aśvamedhaṁ gavālambhaṁ sannyāsaṁ pala-paitṛkam devareṇa sutotpattiṁ kalau pañca vivarjayet

“In this Age of Kali, five acts are forbidden: the offering of a horse in sacrifice, the offering of a cow in sacrifice, the acceptance of the order of sannyāsa, the offering of oblations of flesh to the forefathers, and a man’s begetting children in his brother’s wife.” ( Brahma-vaivarta Purāṇa ).