Announcing the findings at the Mumstock event in London, run by the Mumsnet website, Oliver Newton, brand and agency advocate at Twitter, said 67% of mums felt this way and most preferred information rather than humorous posts.
Twitter established who the mums on the platform were based on how and what they tweeted.
"A lot of brands fall into the trap of thinking you have to be a real comedy account on Twitter, it's all about the Mega Lolz. It really isn't," said Newton, in remarks reported by The Drum.
"The study shows that the type of content people most value from brands is information," he continued. "If you can provide that with humour then game on, if you can't, don't worry about it. But don't feel like you have to be a comedian on Twitter."
He further revealed that the average number of brands followed by mothers on Twitter was 32 and that they were most interested in competitions, promotions, and information on the best time for buying products.
Four out of five mothers (82%) also followed a celebrity and many were now using Twitter to get celebrity gossip rather than reading magazines.
Family and friends were much less important reasons for being on the site, with only 43% saying it enabled them to be closer.
Newton also said that 77% of mothers were accessing Twitter via a mobile device, a broadly similar proportion to the rest of the population.
Several of these strands came together in Procter & Gamble's award-winning Proud Sponsors of Moms campaign, which it ran during the 2012 Olympic Games and which sought to honour the role mother played in helping their children reach their full potential.
As part of this exercise, P&G used Twitter to contribute to real-time conversations surrounding Olympic athletes and mothers.
Data sourced from The Drum; additional content by Warc staff