Sim 2 Pregnancy Mod Idea
Let's have a look. The idea is a nice one, I must grant you that. However, let me tell you something about sim births, so you'll understand why it can not be.
When a sim is pregnant, the new-to-be-born baby doesn't actually exist yet. And it keeps not existing until the time of birth. You know when that screen comes up about the new arrival, and the stork untying some extra strongly tied knots? THAT is the moment at which the new sim is actually being created. And the routine for that is a primitive that nobody can mod or alter in any way... The big problem is that this coin toss you're mentioning, is included INSIDE this primitive that nobody can even look at. So we can't influence it in any way, nor can we even predict the gender of what's going to come. That gender is only known once that window dissappears again.
So, an NPC doctor coming by and examining the mother, all nice and well IF someone would be willing to invent a way to add a new NPC type to the game (which is yet another BIG hurdle), but this doctor revealing the sex of a non-existing sim? I hope you see how impossible that would be...
And this really is a pity, because I've been thinking about such things, too. For my Alien Experiments mod, I actually even wanted to try some in-game gender-changing (A sim gets abducted as a male, comes back as a female), which obviously never happened, either. One CAN change a sim's gender using SimPE, but not in the game itself! That's all part of the same problem, by the way.
But, to be completely honest, this is only the view of someone who has only been modding for little more than a year. Perhaps there are modders out there that would know better than me, I don't know. But now the question is out in the open, maybe someone sees it, and can tell you where to look for a more desirable answer.
I hope to learn from such people!
Thank you for asking, and I hope to be able to do more on your next request (if you have any).
Good luck in your search, and happy Simming,
Thank you for giving me greater understanding of the obstacles in the way of said mod and more of the way sim birth works. You went into more detail than others before you and I appreciate that.
Indeed, getting the NPC to appear isn't the problem. The real problem there is: there IS no NPC doctor, so one would need to be created! Not many people know how to do that, and I'm not one of the few. The beacon would be easy again: whenever a sim gets pregnant, a pregnancy controller is created on the lot. That controller could be the beacon: when a certain amount of time has elapsed since the creation of the beacon, and the pregnant sim linked to that beacon is at home, the doctor could be summoned. And predicting the gender would indeed be just a wild guess with 50% chance of success. Since we already know with 50% certainty that the child will be of either gender, who needs a doctor with such poor skill?
Any how, this is all speculation on how one could go about this and still leaves the gender guessing problem. If only we could see the sim's future...