Sex and the City star Sarah Jessica Parker and her husband Matthew Broderick have reportedly chosen a bisexual woman to act as a surrogate mother.

Michelle Ross, 26, is thought to be carrying twin girls for the couple.

She has previously acted as a surrogate for a gay couple in New York.

Her ex-husband Joseph Erker told Star magazine that she became a surrogate to help others.

He added she had told him she was bisexual, showing him a tattoo of a pink and blue triangle overlapping.

Parker and her husband already have one son, six-year-old James.