I am guessing that when Skyfire and Starscream lived on Cybertron before the war, they had a hard time trying to have sparklings? Especially hard for Starscream?
EXTREMELY DIFFICULT! Theoretically. The particular AU where my Earthspark Skystar family stuff happens follows my Fanfic Series pretty closely, where the two weren't actually Conjunxed until after Skyfire defrosts.
This wouldn't normally change things, but since Conjunxing involves merging sparks, and I've headcanoned that to be an essential part of making babies, it'd make sense for them to have a more "we aren't actively trying yet but if it happen thats great"
However, they knew they would be in for a difficult time.
While the already low fertility of cybertronians in general would be the first hurdle, and the riskiness of carriage in general being the second... Skyfire and Starscream are different frame types. They're both fliers, but that's not close enough for functionism
On a functionist Cybertron, combining of different frame types would be extremely frowned upon, introducing variables outside the bounds of the defined 'functions'. This would lead any information on mixed-frame creations to suggest they have a higher mortality and miscarriage rate (in reality, i think they'd have the same chance of death as same-frame parented sparklings, but the data is skewed by the lack of medical care provided to these carriages AND the encouragement away from carrying in general)
This also means mixed frame type relationships were looked down upon, though not terribly, since through Vector Sigma they could have A Shuttle or Some Seekers... except those in charge of guarding the hotspots for those things might have enough opinions for them to be pushed down the priority list.
In Summary: Sparklings was one of the many seemingly unattainable goals of Skyfire and Starscream in the face of functionism
Which they achieve!
like. in multiple ways. caring for the terrans fulfills some of the bonecrushing hopeless out of reach feeling but then they actually went and made their own too













