Do you have to have an amnio if you have a c/s before 38 weeks?

gapgirl972001

I have had 2 c/s already.  My first was at 35 weeks due to pre-E and a failed induction.  She had no problems and never spent a second in the NICU she was only 4lbs 13oz. 

My 2nd was done at 39 weeks and again no problems but a failed VBAC/induction.  

The dr is taking this baby by 38 weeks the latest probably 37 weeks due to a thin uterus when I had my 2nd.  Someone told me I would need to have an amnio before getting it done to see if the lungs are developed.  I never heard this before and will ask the dr at my next appointment but figured I would ask here as well.