I'm begging (and bribing) on my hands and broken knees to share your post about Eldar reproduction!! (and only if you want to too ofc!) I'm struggling to write about the whole reproducing stages about my own Dark Eldar ocs, and your insight would be helpful and greatly appreciated 🙏💚
Oh god thank you and have a kiss on your forehead. I love giving my Aeldari blorbos little babies so I've thought about this too much.
While the previous post about more general biology wrt writing smut was based on some actual source material, we are going to less charted territory.
Red trying to piece together Aeldari reproduction based on vague hints and prophetic visions
As far as material we have this in xenology:
And several mentions in passing that:
The process is long (several human years) (too many mentions here and there)
It's crippling for the female (as Marazhai says: she's at her most vulnerable and useless on a raid)
The birth is not fun for the mother (Da Big Dakka)
Twins are a thing (Path of the Eldar) but they're rare. Can't recall a mention of triplets but there might be.
They don't seem to care much about short flings at all and there's even sort of "dedicated" spaces for that on the Alaitoc Craftworld in Path of the Eldar
Outside of pregnancy there doesn't seem to be a big sexual dimorphism between males and females ie they have the same physical strength as a rule
They have boobs (cfr female models) that aren't excused in lore as being something else than milk glands, they're aware of what milk is (Marazhai insulting craftworlders as "milk-blooded" ie weak)
Babies stay with their parent(s) for a while and for Craftworlders, they are psychic at birth and highly attuned / melted with their mother. They progressively separate and become their own person, alone inside their head (Asurmen)
Kids need to learn to speak and use psychic powers and a bunch of other things, they're not born fully capable like a baby giraffe that can walk in an hour or so. (Asurmen)
They inherit traits from their parents
And then there is the Drukhari insistance that being born from a Real Vagina(tm) is a feat and difficult to achieve in Commoragh.
This is honestly what we have and it's not that much.
We are now moving into headcanon space
Pregnancy
I don't think fertility is the biggest throttle on new Aeldari babies, I think it's soulstones for the Exodites / Craftworlders and Commoraghan culture for the Drukhari. As in, they can have children when they put their minds to it, it's more that given the circumstances it's a Huge Thing to do.
You have to consider that Aeldari were created as weapons of war. Not having a constantly running "reproduction" program running in the background frees up energy. So, I don't think they have spontaneous ovulation cycles either. I don't think they menstruate either, not only because of that but menstruation as a whole is rare in the animal kingdom.
All in all, I think it is only in specific instances that the body will expend energy on making new babies. Which is why they can be so casual about ONS and flings.
In my headcanon, the body shifts into baby-making mode with repeated exposure to psychic waves or hormones or whatever that the male (or both) would secrete at stage zero. It's not such a crazy idea since human sperm also contains prostaglandins and other signalling molecules that can get absorbed through the vagina but granted not a lot of people know that.
For example, what could be part of the whole process of getting the Eldar body ready for pregnancy would be dissolving the cartilage plates that they have on their stomach, so it can expand around the growing baby and not jab it in the eye. Sort of like in humans we secrete relaxin, that allows ligaments to expand so hips get a bit bigger (and your feet). Or we start making extra blood. The placenta does a lot of this work in humans but the director of the process could be the interplay of the male and female body for Eldar.
In the same way the male Eldar body then also adapts and starts delivering other things (the multiple organs mentioned in xenology or progressive gamete thing). Then we move onto a different stage of reproduction and the feedback loop of each affecting the other keeps the pregnancy running along smoothly.
In that sense then both of them have to keep going at it for a long time, with the man and woman needing to stick around each other. That ties down two of your designer race soldiers but I think that was the point. The Old Ones created two species to fight the Necrons, the Aeldari which were more rare but more refined and and the Krorks (later Orks) that were canon fodder and reproduce mushroom-like, so much quicker. But for Aeldari, when they fight they won't be encumbered by something like pregnancy on the battlefield, but they can reproduce, it just takes time and stability.
Veering into even more speculation, but imo unequal gender roles are a result of unequal force between sexes and the fact that one sex has 99% of the burden of reproduction - so I just like making it so that both Eldar men and women have to chip in continuously and it erases that imbalance. Plus it ties into the "progressive gamete delivery" shtick.
With all that being said, I do think that if for example the male disappears, the pregnancy just stops. It doesn't need to be bloody and tragic either. They cristallise, supposedly, so you could just HC that the unborn foetus dissolves back.
Birth
As for birth itself I touch upon it a little in the other post about anatomy but Xenology mentions that their bones can bend. Human women have hips that are different and wider to allow a babies' head to come through. Aeldari men wear banshee armour and the women wear the Striking Scorpions kit so let's assume they're less visually different. Aeldari aren't marsupials so children come out probably more or less fully cooked, so it's still a whole thing to get out. It's mentioned as a bloody, painful thing. I HC (pure HC) that they might come out a little smaller but that the hip bones simply bend under the pressure for birth. Not fun.
