Abstinence advocate and teenage mother Bristol Palin is pregnant again

Former US vice-presidential candidate Sarah Palin's daughter Bristol, who launched an abstinence campaign after giving birth as an unwed teenage mother, announced she was pregnant with her second child out-of-wedlock.

The disclosure came a month after the young celebrity's wedding with Medal of Honour winner Dakota Meyer was called off.

Palin, whose mother soared to fame as the 2008 Republican candidate John McCain's running mate, directed Twitter followers and Facebook friends to her blog, where she announced the pregnancy.

Her representative, David Martin, and Palin family lawyer John Tiemessen confirmed the blog post.

"I know this has been, and will be, a huge disappointment to my family, to my close friends, and to many of you," the 24-year-old Palin wrote, before asking for privacy for her and her son Tripp.

"I do not want any lectures and I do not want any sympathy," she said.