Some of my friends tried Clarins Tonic Oil and found it effective for them. You could give it a try (if you haven't).
You can also try making this DIY stretchmark cream. The author used it for both her pregnancies and did not have any stretchmarks (and she mentioned that she has had stretchmarks on her legs when she gained weight during her non pregnant period):
http://thehealthyhoneys.com/diy-stretch-mark-cream/
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