Is a Fat Transfer Worth It For A BA to Go from A-B Cup?

Fat transfer to the breasts is still a developing procedure, and generally not a good idea for most patients. The results are unreliable and the amount of improvement is questionable.

While your size goals appear most compatible with what fat injection breast augmentation can achieve (1/2 cup or so), the issue is one of reliability of the result. Fat injection breast augmentation is far from a perfected procedure and should still be viewed as a work in progress. How well the fat takes and what size can be achieved, and the cost and effort to do so, remain issues that would not be considered completely reliable. A 'traditional' breast implant is the most assured and cost effective approach to achieve your breast size increase goals.

It is my opinion that fat grafting should not be done to the breasts for purely cosmetic results, a small implant will give you a guaranteed result and you will not get excess calcifications in your breasts when you have mamography as you age.

Fat grafting or lipotransfer is becoming a more reliable technique for breast enhancement and shaping, and if you do have suitable donor areas, and wish a modest increase in breast size if may indeed be 'worth it'. We use the technique often in improving breast reconstruction, though grafting can give a one-half cup increase in the breast for those who simply wish to avoid a breast implant.

At this time, larger volume fat transfer for breast augmentation is experimental. Fat transfer today is great for smoothing out contour irregularities and providing a more aesthetic shape. The central issue is that fat removed from one location lacks blood supply when placed in another location. Its survival depends on the body's ability to quickly grow blod vessels to provide nutrition. Think long and hard before you attempt large volume breast augmentation.

Fat injections for the breast is in a state of evolution, and I personally do not recommend it for a routine breast augmentation.  Also, after your weight loss, you should be evaluated to see if there is any redundant skin that needs to be addressed.