I agree with the other consultants that the pre-op tests can include lab work as well as possibly EKGs (electrocardiogram). In my practice, a "mommy makeover" is designed to restore the parts which pregnancy stretches out, generally the breasts and tummy. Even before scheduling a case, we take a detailed history and physical exam, looking for conditions which may make the patient a "higher risk" candidate or predict a longer recovery. For example, motion sickness is sometimes a risk factor for post-op nausea. As a rule, I won't offer a tummy tuck to an active smoker, because the chances of delayed wound healing are quite high. In addition to the labs mentioned above, I inform active smokers that if their urine tests positive for nicotine, their surgery will be postponed.
If in doubt, consult with your family doctor or OB, who may be able to assist you with pre-op clearance. As exciting as it will be to reclaim your prepregnancy body, you want to have a safe passage through surgery and recovery. Good luck.