Minor confusing issue that Bernie still does not know that Superman and Clark are one in the same. Lois is right at her 3rd Trimester (knowing the sex of the baby) and he has not been brought into the loop yet.
You can find out the sex of a baby as early as 16 weeks by ultrasound. That's early in the second trimester. I was also a bit surprised that they hadn't been seeing Bernie, but maybe they decided that they'd only go to him if the ultrasound or other tests showed abnormalities.
Waiting on how you get Clark a transplant as the only way would be to expose him for a period of time to Kryptonite and that would greatly elevate his BP and heart rate (at least it has every other time he has been exposed) and how would his severely damaged heart handle that.
I don't think it was used in the show, and is therefore never (or rarely?) brought up in L&C fics, but red sun spectrum lights will take away Clark's powers without hurting him. He just reverts to what's normal on Krypton. I imagine that Clark wouldn't figure that out until Zara & co. show up and comment on the different color sun, but we're way past that point now. But I expect that if they knew about red sunlight's effects in the story, they would have used it when Bernie took Superman's blood.
I haven't decided whether Clark's going to die or whether DC's pulling a bait-and-switch on us. Maybe Clark ends up fine and Lois dies in childbirth? Or they lose the baby? Lois is accidentally exposed to the kryptonite that they're using to make Clark vulnerable enough to operate on?
