Glad you are doing well and my apologies for the slow reply.....Mardi Gras cam early this year!
Stretch marks are basically a tear in the deep layer of the skin, so, it stands to reason that the added weight exposure under the breast would leave them more prominent in that location. There is no great treatment for them unfortunately, as repair of the dermis and thickening of the skin would be necessary to make a real difference. But, technology is always advancing and if I hear of anything....creams, lasers, or otherwise, I will let you know!
Best to you and your's,