Turn in I-485 application now or 3 months later?Please advise!

Hi,

EB2 LC just approved. I can not get complete medical exam because of pregnancy until about 3 months later (late October). We have two ways to choose:
1.file 140 and 485 concurrently now with complete family member's document, but just part of my medical exam, turn in my complete exam later, or wait for REF.
2. File i-140 now, and I-485 3 months later.

Sombody said documents may get lost if not ted together.

Can anybody have any suggestion on which should I choose?

Thanks!