Judge Leonard Gerber, who sentenced Darren Ely, 31, to nine months, told his wife Sharon, 24, that she would have received the same sentence had she not been pregnant.
The couple, who live in Overton Court in North Lincolnshire, pleaded guilty at the Old Bailey to violent disorder.
The court heard that the couple had travelled to London in June for the riot that was attended by about 10,000 people and caused an estimated pounds 2m damage to the capital's financial heartland. The judge viewed a video of rioters throwing objects in which Mrs Ely hurled flattened drinks cans and a bottle and Mr Ely, drunk and bare-chested, threw stones at police officers.
Judge Gerber told the couple: "You took active parts in this riot and were throwing articles at police, acting with great vigour. This court has a duty not only to you but to the public. It has to be clear that such behaviour can not and will not be tolerated. Those who participate in violent disorder have to go to prison."
Mr John Lloyd-Jones said for the defence that medical opinion was divided on Mrs Ely's pregnancy, with doctors saying the baby was due on dates ranging from December 24, to February, but it was now agreed that she was seven-and-a-half months' pregnant.
Mrs Ely, who had complained of pains before the hearing and was allowed to sit while being sentenced, was led out of the dock by a guard.
The couple could be released from prison after serving half their sentences.Reuse content