Is it for a c-section pre op? If so I would imagine they will do a medical history and have a look in your mouth so grade your airway. That's from nursing experience though not from personal experience!
It may depend on who you see, I was referred for having a BMI over 30, all she was interested in was giving me healthy living leaflets. Yes I'm overweight, I was a size 16 before I was pregnant but reasonably in proportion for my height. I'm a nurse so know what to do to loose weight, doing it is another thing.
I told my midwife and she said that 'that one always does that' and then other person was more helpful.