Meconium in your amniotic fluid is only a problem in a very small percentage of cases. It depends on it's consistency and colour as to how immediate of a problem it is. If it's just lightly stained your fluid then it just means the baby was stressed at some point in the past. In the absence of any other indicators it's not significant. Dark, thick fresh mec is more of a reason for concern.
The best way to avoid the problem of meconium stained liquor? Don't let them break your waters!! They can't stress about what they don't know about!