B12 level during pg

Just wondering what everyone's b12 levels did during pg? I know the last time it was checked (March I think) it was in the 600's. It was only 302 on the labs they drew a few weeks ago. Frankly ladies, that scares me. Why has it dropped so significantly? What does it mean for the baby? Just wondering what everyone else's experience was with B12 during pregnancy??

I'm sure that the numbers can be different - they can't be counted the same way??? We have different numbers and both Dr approved/ recommended - so strange. I wish we had a way of knowing or standardizing so we can compare more easily.
My hematologist wants my b-12 to be above a 250 - we have been fighting with it for a year. When I had IUI it was at a 240, that was 6 months ago - now I'm at a 160. That drop is with me 6 months pregnant taking sublingual 2 x's a day and a shot once a week - we just increased my shot to; 1 one week, 2 the next, 1 the next, etc. and we'll check again in Oct to see what that has done -- but both my b-12 and my iron took a huge hit by 5 months.

~Kim