The pair recently joined forces to publish Your Best You, which advises Irish women on how to make the most of their assets.
And Brendan explained how the book has spawned a separate project for the presenters, which will see them dishing out some more pearls of wisdom on the tricky job of maternity dressing.
"We had a chapter in the new book on how to look good pregnant and I was in England talking about it and two women said to me, 'There's a book in that'," he said.
"So we've done a YouTube video which we're going to post soon.
"It's all about how to find clothes when you're pregnant, because it is really hard and also having babies is kind of pandemic in Ireland at the moment. Maybe it's just our age that all our friends are having babies and starting families," he said.
A number of famous names are expecting babies in 2013.
Author and actress Amy Huberman is due her first with hubbie Brian O'Driscoll in about eight weeks.
Model Pippa O'Connor and Brian Ormond will hear the pitter-patter of tiny feet in April, as will TV3 star Anna Daly.