I have had to do a research on those before and and therefore think I can answer it.
Stretch marks comes when there is rapid gain in weight and this is mostly common in pregnant women. It can be seen on the abdomen as the baby bump grows.
Stretch marks are sometimes genetic. It the lady's mother had stretchmarks when she was pregnant, the lady will most likely have them too.
Stretch marks aren't that bad except for the fact that some people don't like them. It's just a tear in the inner layers of the skin due to the pressure from the baby-infused weight gain.
Stretch marks will most often become less visible as time progresses although some tend to linger.
Taking in lots of vitamins especially vitamin C will help fasten the fading process and also the application of cocoa butter.
Stretch marks aren't a visible in dark-skinned people as they are in fair people. That's an added advantage for the dark-skinned people.
Pregnant women should try to ensure less rapid gain in weight and should watch their eating pattern.