Answer to this depends on type of birth mark you have. If it is flat and only as dark colour then q switched Nd YAG laser can help it lighten. And if it's elevated above skin surface then ablative laser treatment will help flatten it. Complete removal of birth marks is not always possible and they may recur even after successful treatment. Take all these factors into account and then go for treatment. Don't keep unrealistic expectations as laser treatment are little costly. Visit a qualified dermatologist for further details and stay away from quacks who have cure for anything and everything.