Breast fat grafting

I just found out today that there is such a thing as chest fat grafting.

I had heard of breast surgery, but I didn't know about fat grafting.

My breasts have sagged a lot after giving birth and breastfeeding.

I'm not paying much attention to aesthetics because I want to breastfeed my child, but now I feel very insecure.

Breast augmentation involves inserting implants, so I was a bit hesitant, but I'm a little curious about autologous fat transfer.

I'm curious about side effects or anything like that.