Jessica Alba has given friends leather bracelets and told them not to take them off until after she gives birth.

The 'Fantastic Four' actress, who is expecting her first child with fiance Cash Warren in May, had a baby shower in Los Angeles at the Ever After Tea Shop, where guests including Kim Kardashian and Rashida Jones were asked to take part in the bizarre ritual.

An onlooker said: "Jessica made sure everyone was wearing a leather bracelet before they all launched into a 'life, love, health' prayer. She then told them they aren't allowed to take off the bracelets until the baby is born."

Guests at the shower, which was held earlier this month, were treated to skewers of tiger shrimp and chicken, mini doughnuts and strawberries dipped in white and dark chocolate, washed down with drinks such as white wine, lemonade, iced coffee and milkshakes.

While most of the gifts Jessica received were in yellow or green, the 26-year-old actress reportedly told guests she is expecting a baby girl.

Jessica and Cash are rumored to be naming their daughter Honor Warren.