Michael, 52, reportedly got the news just days before his daughter declared that she is cutting all ties with him and vowed to never speak to him again, reported TMZ.
Major, 29, who is just three years older than Lindsay, had a tumultuous relationship with Michael. He was arrested on a suspicion of domestic violence in Florida in 2011 following a quarrel with Major.
Lindsay's half-brother is expected to enter the world in three months.