Been having a massive need for fics I haven’t read with massive infants that are either too big or nearly too big from being overdue. Honestly, anything with the infants being bigger and larger than normal and the woman struggling to birth them is good for me! I just need some good story suggestions! Please and thank you! 

Have you read anything by BoB-Baby-on-Board on Devianart? Highly recommend Birth of a Big Baby, it's exactly what you asked for and probably the holy grail in this "genre"

https://www.deviantart.com/bob-babyonboard

There's also a few good series that follow the growth of women who become overdue with multiples and end in births, I'll link the first chapters of those stories but feel free to skip to the end if you're only interested in the birth aspect:

https://www.deviantart.com/moo9731/art/P...-887785041

https://www.deviantart.com/komperaklause...-873687873

https://www.deviantart.com/hyperpregnanc...-842079245

Basically all of these are some of my favorite stories ever, so if you know of more of the same type please do share.