I find the baby boost store description and the game guide description to be a little conflicting and would like to know what people's experience has been with multiple doses.
So, the store description says:
Multiple doses can DECREASE the effectiveness.
While the Game Guide says:
Multiple doses may cause TWINS or TRIPLETS.
Which do you think is correct? Have you given multiple doses to your little people? Have you had any increase or decrease in fertility? any increase in multiple births?
As for myself, so far, I've stuck to the store description. I give baby boost only when I have a couple of unsuccessful "tries" in a row or a doc consult says one or both of them need it. I've never given more than one dose to the same little person (I use notes in the family section to keep track.) I always have 5-6 kids per couple.