How much will sitting affect my volume at 4 weeks post op BBL?

Thank you for your question. Every surgeon will have his/her own preferences as to recovery for specific procedures. At 4 weeks the pressure caused by sitting is not sufficient to affect viability of the fat cells and so the postsurgical position depends basically on comfort and any other operations that have been performed. That said, you definitely have to choose your surgeon correctly and make sure that he/she has the training and experience to meet your goals with absolute safety.  Best is a Board Certified Plastic Surgeon with specialized expertise in this procedure.

The answer will vary depending upon the plastic surgeon who performed your BBL.  I recommend that my patients minimize sitting, even with a pillow, for the first two weeks.  If they must sit, every 30 minutes or an hour, they should get up and stand for a few seconds to take the pressure off.   This reduces the chance for fat necrosis. I usually recommend about 6 weeks before sitting without a pillow. After 6 weeks the fat has revascularized, and patients will have a very good idea of their final results. 
Kenneth Hughes, MD, Board Certified Plastic Surgeon
Los Angeles, CA