As every new parent knows, keeping up with the Joneses can be an expensive and morale-sapping exercise where baby gear is concerned, as point-scoring dads compare off-road buggies and mums indulge in stealth boasting about the thread count of their organic cotton babygrows.

But with a royal baby due next month, keeping up with the Cambridges is going to require a different level of competitiveness altogether.

And, according to new figures from the Centre for Retail Research (CRR) it will have a considerable knock-on effect for retailers.

As parents upgrade their prams and pushchairs to copy the one Kate Middleton will soon be pushing around the Buckingham Palace gardens, the CRR expects to see a 13% increase in sales of such baby transport.

It should boost total spend by £33 million to £288 million. Early indications are that the royal preference is for a light blue Bugaboo, which costs around £800.

Factor in the champagne that will be bought to wet the baby's head and the collectable souvenirs and memorabilia that will soon go on sale, and the royal birth will boost the UK economy by an estimated £243 million between July 1 and August 31.

"One of the biggest factors will be the unintentional royal brand endorsement," said Professor Joshua Bamfield, CRR director.

"The carriage of choice for the royal arrival will no doubt become this year's best-selling pram for new and existing parents.

"The 'Kate effect' has already taken the fashion world by storm with each of her choices flying off the shelves within moments of her leaving the house.

"This trend will follow for the infant's baby grows, rattles, first bike and so on."