From my research, this is not as common in "breeder" stock as it is in...think "puppy mills" of the chicken world. I have a 20% chance of saving my favorite RIR who hit 2yrs old this past month. She was on deaths door literally, on my shoulder and could barely breath from the fluid buildup in...
Had this same issue with my one year old Americana last week. Brought her in the house and sat her down on a towel in my lap to relax. Maybe 30 minutes go by and she plopped out egg without the hard shell. Still had the softer membrane shell that contained the yolk/white. Thought we were good to...