After breast feeding there are a number of changes that take place in the breasts. Ideally breast surgery is performed in women who are not producing milk and whose breasts are no longer changing in size/shape. When breast feeding is completed there is a slow decrease in the size of the breast glands and a slower change in size and shape. Generally, one should wait at least 3 months before having anything done although waiting 6 months is better. At that time, most if not all post-pregnancy changes should be complete. By waiting until all the changes have finished, it is much easier to create a more predictable result from any sort of breast lift and/or reduction.
For the best results seek the consultation of a plastic surgeon certified by the American Board of Plastic Surgery. They have a website listing all the certified plastic surgeons. Members of the American Society of Aesthetic Plastic Surgery will all be board certified in plastic surgery and have demonstrated an interest and competence in cosmetic plastic surgery as well.