I've written a near-future SF story that includes, as part of its worldbuilding, full artificial gestation technologies. I've been digging into some detail about the sorts of problems that would need to be solved, and while I've found good information, there's one big question I can't answer:

What's the benefit of maternal movement, particularly in the first 6-8 weeks?

I found a bunch of stuff about (chicken) egg turners, suggesting motion affects vascular development (affecting nutrient uptake and oxygen absorption). This makes sense, but I haven't been able to find similar research on humans. Everything I've found on maternal movement involves exercise and the benefits of certain hormones, which (in a SF setting, at least!) could be provided artificially. And most of this research covers later development rather than the more fragile early weeks.

I'm not talking about exercise per se, but average day-to-day movement: standing, sitting, rolling over at night. The effects of gravity. Does it even matter in a situation where birth position isn't going to be a consideration? I suspect it does - but do we know (or suspect) why?

This being SF, I can "solve" whatever problems I want, but I'd like to be able to toss at least a little lip service to science, especially since I'm not casting forward more than a hundred years or so.

Anybody have links, or even better terms I can use to search? Throw science at me! I can take it.

TIA to all!