I am for the first time trying to use custom pregnancy outfits in my game and managed to make it work for th most part, but still running into one small issue with pregnant sims always showing up in Maxis maternity wear on community lots.

So first of all I need to mention what mods I use for this purpose:
- BO's PlanMaternityOutfit
- Squinge's PregnancyWearAnyOutfit (EP8 latest update)
- Several custom outfits with pregnancy morphs, made available in the maternity category by editing their property sets (either by me or the original creator)
- The clothing tool which is not pregnancy-related but helpful to easily buy/change outfits

So whenever a sim is pregnant with a bump, I will direct them to plan their pregnancy wear using a normal dresser and chose a maternity-compatible outfit from their wardrobe. They will wear it immediately, however they might revert back to the Maxis default outfit after showering or when directed to "change into" maternity wear. To fix that issue I then resorted to setting the custom maternity wear as their everyday outfit as well, and make them change into everyday.
This works for the most part but there is one problem that I didn't manage to fix: whenever I am playing another family in the rotation, and visiting a community lot, pregnant sims from other families will always show up in their default Maxis maternity wear no matter what I do. (Funnily enough, they wear the intended custom outfit when visiting other playable lots though)

I know that using defaults would at least get the Maxis fulgly maternity wear out of sight, and I intend to do that eventually, but it would still not fix the issue with Sims wearing the default outfit that was randomly picked by the game instead of the one I chose to fit their personal style and the current season.
This is of course not a big issue and in no way game-breaking, but still bothering me and I wonder if I am not using these mods in the right way. I guess some people here have much more experience with custom maternity wear?

The PregnancyWearAnyOutfit mod seems to work best if you use it with the other outfits and not the maternity category. I've not had any issues with sims reverting to other clothing types on residential lots if they're wearing regular casual or other clothing types (I generally don't use the maternity category with this mod, since any outfit with a pregmorph is available as other categories, and if there isn't a morph I'll just change their clothes). Community lots could have other issues, though.

BO's mod seems to have a known "conflict" with Squinge's mod, but will work with it as long as BO's mod loads last. There's more info in the comments on page 2+3 in the download topic: http://www.leefish.nl/mybb/showthre...?tid=911&page=3
It's entirely possible the issues you're having are related too this.

Thanks for pointing that out! I must admit, I read the description of the mod but not the comment thread, good to know that there is a known conflict. I renamed BO's mod so that it loads after PregnancyWearAnyOutfit and I will see if it improves the situation

Initially I wanted to use the maternity category so that I can flag only the outfits with a pregnancy morph in there, and have only these show up when I plan the pregancy outfit instead of the whole catalog. Also my Sims can have a specific outfit decidated to pregnancy which I think is neat. But of course changing everyday outfits is not that big of a deal.

I've recategorized outfits as maternity (plus casual), but find it's not the most useful category, especially with Squinge's mod. It seems to counteract the sims changing into maternity, as opposed to using casual. In my game, it's as if the maternity clothes don't exist (can't even remember if I've got defaults for them).

I also have pregmorph defaults for EAxis meshes, which makes them more useful (I have various recolors, plus texture defaults for some of them). That way, most outfits can be maternity outfits (or they can just continue using whatever they were wearing, if I'm being lazy), so I have a lot more options.