Strawberry birth marks found in infants are called infantile haemangioma. Statistics reveal that one out every 20 babies can have these. Some believe that these are more common in babies born prematurely.Experts believe that the causes behind strawberry birthmarks can be either genetic or these can occur by chance also. In any case it is important to keep an eye on these as some marks go away with time but in some cases, they grow in size and also become darker with time.