This is another question that seeks to provide assistance in the design of ''Eosi Humans'' an alternate human species which makes up the population of my fantasy world ''Diggoran'' ( Pronounced Die-Ah-Ran ).
At a few points in Diggoran's complex lore, certain women have experienced pregnancies in which the fetus undergoes accelerated aging and grows into a teenager in the womb within a 9-14 months' time ( The gestational period for Eosi humans is 9-17 months ). The weight of a teenaged fetus at roughly 121 pounds combined with the greater amniotic fluid should equate to roughly 149.45 to 150 pounds of maternal weight gained during these rare pregnancies.
While this impossibly ridiculous in accordance with real-world humans, Eosi humans are capable of undergoing such pregnancies as 149.45 pounds of pregnancy weight feels like 40 pounds to them. This means that the more common pregnancies should weigh even less according to their physical perspectives. Eosi humans are also capable of carrying up to 11 children in a single pregnancy and birthing them vaginally in under 1 hour with little to no pain. ( I was previously recommended to design their pelvis like snake jaws along with other unmentioned details so that they are capable of achieving this )
Eosi humans maintain their pre-pregnancy agility during pregnancy, even in its lattermost stages. At any time during a single to octuplet pregnancy. Eosi humans should be capable of performing advanced gymnastics, athletics, heavy lifting and minimal amounts of basic self-defense. They don't ''waddle'' during pregnancy and remain largely comfortable during the entire ordeal.
Also, Eosi humans are capable of bi-gendered reproduction which means that both males and females can get pregnant but that's a whole other can of worms. Eosi Humans can do the questionable things they do because they evolved to be ''creative survivalists''. Their homeworld of ''Eos'' is a very hostile planet where all the wildlife can and may do unspeakable things to you.
Eosi humans used to be at constant risk of extinction up until 5,000 years ago when they managed to gain some level of dominance over their hostile planet.
I have been looking for a scientific way to explain the many obscure features of Eosi humans although I am the type of writer who is fully willing to say ''fuck it, let's do pure unscientific fantasy'' if the science doesn't allow for things to go my way.
I asked a previous version of this question on Reddit about a year ago and the only answer I got was ''just make them taller''. Eosi humans already stand at average heights of 6'5'' to 6'6'' and I really don't want to make them taller.
Are there any biological design techniques that I can use to make these features functional in Eosi humans? Perhaps some redesigns to their bone and muscle structures?
Any help would be greatly appreciated.
Thank you in Advance.