From more discussions with Eoin, keeping in mind Durer’s Young Furleger:

> When you saw dresses with pregnancy pleats, what was the skirt like?

I’m almost sure I’ve seen more than one example, but the one that comesimmediately to mind is the Shinrone Gown as explained by Kass McGann of Reconstructing History. It’s online, so you can examine and make your own conclusions. IIRC, the skirt was separate from the bodice (made of trapezoidal gores with some weird welting), and gathered or pleated to it; and the pregnancy pleats on there were diagonal, more horizontal than vertical, making the front of the gown shorter/longer as much as narrower/wider. Which makes sense; one needs more length of fabric to cover a larger girth without the hem pulling up.

I think another example was earlier (shinrone gown is late 1500s IIRC), like 13-1400, on the gored geometric shift pattern, and may have been n the Museum of London book.