New York, Nov 16 Former US Vice President candidate Sarah Palin's highly anticipated memoir, Going Rogue, reportedly describes heart-wrenching anguish about her eldest daughter Bristol's pregnancy playing out before a national audience.

However, the 413-page memoir does not contain a single reference to the father of her grandson, 19-year-old Wasilla resident Levi Johnston.

Just after Senator John McCain chose Palin as his running mate in August 2008, Johnston was thrust into the national spotlight when Palin abruptly announced her unwed daughter was pregnant and the couple would marry, The Sydney Morning Herald reports.

Earlier, Palin had also said that she was not aware that Bristol was sexually active before she learned the teenager, then 17, was pregnant.

The 17-year-old gave birth to son Tripp, in December. But, Bristol and Johnston split soon after the birth. Johnston was under extensive media scrutiny after fathering a child. He has repeatedly sparred with his former mother-in-law-to-be since the couple broke.

He also continues to warn Palin that she should leave him alone, or he might dish some serious dirt that "will hurt her." (ANI)