Welcome to HealthcareMagic froum,
are difficult to treat ..if they are extensive then rule out any hormonal
problem...there are 3 diff types of stretch marks -white,black and red.So if it is black then try tretinoin
cream locally ...If it is white then you can go for lasers too...Othere wise there is a new technique which lot of doctors are trying is DERMAROLLER
,which can even be tried.For prevention you can use olive oil or vit e oil locally.