I did some testing awhile back regarding when the massage needs to happen to get multiple births - I used MCC Control to check the pregnant Sims to see how many nooboos were in there. I thought that the massage needed to happen within 24 hours before birth, but I saw conflicting information saying that it was within 24 hours of the initiation of pregnancy.
My results were:
- 1 Massage within 24 before birth - nearly always resulted in twins (rarely triplets) for as long as the massage buff was up, but when it fell off there was a high chance that the number of nooboos would go back to 1.
- 1 Massage within 24 hours of pregnancy - often, but not always, resulted in twins; rarely in triplets.
- 1 Massage within 24 hours of pregnancy + 1 massage within 24 hours of birth - Always resulted in multiple births in my test - I got triplets this way about half the time.
This wasn't a scientific test, of course, but I tested across about a dozen different Sims, so this is what I go by. My ongoing results have been consistent with what I saw in my test. Of course there have been several times when I was wanting just 1 nooboo, so I've done NOTHING to cause multiples, and got twins anyway.
This is how I've always used the On Ley Line lot trait and fertility massages as well.
I never thought to test it using MCCC because the above timing has worked for me and my sims, starting with my Mori Legacy (no MCCC).
When seeking multiple vampboos, I learned from my 100 Baby Challenge that we can simply swap the On the Ley Line lot trait with the On the Dark Ley Line lot trait.
My 100 Baby mama (spellcaster) had twin vampboos with non-occult baby daddy sims.
I vaguely recall that a Fertility massage's effect used to be shorter.
While playing my BDD last year, I remember noticing that it lasted 24 hours and wondered when/if that had changed.
It's true! I just checked Carl's guide on the Wellness skill (which hasn't been updated) and it says: "Fertility massage: +1 12h Happy Moodlet, increased likelihood of twins/triplets"
The longer window of time is really nice!
For me, even doing all the above, my sim can still give birth to a singleton if I join them at the hospital.
So, if i want multiple births (I usually do), I either opt for a home birth or "Send alone" to hospital.
Has this also been your experience?
Thanks for sharing that you tested fertility using MCCC!