When does the gender of the baby get decided?

I think in the 3rd trimester, I left strawberries and and pop music too late, so even though he spent the whole day dancing it was still a boy :#

My sim was pregnant and MCCC said that he (alien babies) is having 1 boy but since I wanted more children I made him eat 2 apples in the 3rd trimester. After that I checked MCCC again and it said that he was going to have 2 girls and 1 boy (which he did end up having). My guess is that it decides the gender at the beginning of the pregnancy but then you can influence it. :*

I'm so confused with this topic because how would you know if the gender has changed anyway, unless you delete a save. I think it's decided at birth :)

The baby's characteristics, gender included, are determined at birth. I stumbled upon this in a play through where the father was bitten and turned into a vampire after conception, but before birth. The child was born a vampire -- something that should have not occurred if this was not the case. And so, at the moment of birth the game randomizes characteristics from the two parents at that time, not at conception. It will evidently also take into consideration the foods eaten and music listened to in determining gender probability at that time as well. This makes sense, as it seems to utilize the three day period between conception and birth as a running counter to skew statistical probability and then does its calculating at the end.

EDIT -- Nuts. This thread is from last year. I already replied to it. Well, there it is.

"MollyJoySims;c-16249407" wrote:
I'm so confused with this topic because how would you know if the gender has changed anyway, unless you delete a save. I think it's decided at birth :)

Many people, in order to test said question, have restarted from their last save-point, and that’s how they know if the offspring has changed or not. :)

With the use of cheats and mods, it appears that the gender and amount of offspring is determined at conception, but it can all be easily manipulated to change throughout the trimesters. I haven’t personally done much testing on the subject, but I use MCCC and the only time my Sims’ pregnancies have ever changed is after they’ve done something that naturally influences them.

"OEII1001;c-16249440" wrote:
EDIT -- Nuts. This thread is from last year. I already replied to it. Well, there it is.

@OEII1001 In all fairness, "last year" was only a week ago! And I'm still around looking for answers on this, so you aren't resurrecting a dead topic. :)