I've been playing Sims 4 for a bit now. I've had babies disappear and women go into labor for weeks on end, never having the child. So only procreation glitches so far.
I don't play the game, just build and I had half my house just vanish when I loaded, doors and windows also it's rather annoying, lol.
I'm lazy. I use the premade rooms. Report the glitch on their forums. They read them and if it's a common enough problem, they can focus on fixing it.
It's to do with the 'bb.moveobjects' cheat, it happens mainly with the boxes of somethings clashing and then they just vanish, it's odd and it's been around since the game was released but it even happens without the cheat ;_;
I had that too. Maybe it's a widespread issue? I was making a family, when the mother gave birth, it took about a sim week and then when the parents were elders the baby (only a day or two old) disappeared and their oldest (a teen) burnt to death. So far, sims 4 is a really sunshine, lollipops, and rainbows everywhere kind of game for me. Anyways, I can probably do this.