Palin's daughter gives birth to son

The daughter of former US vice presidential candidate Sarah Palin gave birth to a son, a magazine reported.

Bristol Palin, 18, gave birth to Tripp Easton Mitchell Johnston on Saturday, People magazine reported online.

He weighed 7lb 4oz. Colleen Jones, the sister of Bristol's grandmother, told the magazine that "the baby is fine and Bristol is doing well".

The Alaska governor's office said it would not release information because it considers the baby's birth a private, family matter.

The father is Levi Johnston, a former ice hockey player at Alaska's Wasilla High School.

Mrs Palin announced on 1 September, the first day of the Republican National Convention, that her unwed daughter was pregnant. The campaign issued a statement saying Bristol "and the young man" would get married.

Levi Johnston's mother eventually disclosed that her 18-year-old son was the father.

The following week, the young man attended the convention in St Paul, Minnesota, when Mrs Palin accepted the vice presidential nomination.

The announcement that the unmarried Bristol Palin, 17 at the time, was pregnant immediately drew concerns that it could damage Mrs Palin's credibility as a religious conservative.

But many observers noted the pregnancy served to humanise the Palins and showcase the candidate's rejection of abortion.

Sherry Johnston, Levi's mother, said in October that Bristol and her son were considering a summer wedding.

Sarah Palin and her husband, Todd, have five children ranging in age from Trig, 7 months, to Track, 19. In between are Willow, 14; Piper, 7; and Bristol.