According to Cleveland Clinic: "Weight loss or gain: If you lose a lot of weight, you may have extra, looser skin. If you gain weight, you may have bigger cheeks. Both situations can accentuate nasolabial folds."
If you have gained 12 lbs. overall, the result should not be a deeper nasolabial fold than before. Are you asking if the skin lost elasticity because you gained and lost weight?