Does traveling cause a dip in milk supply?

A close friend of mine was at a breastfeeding support group recently and was told that many moms see a dip in their milk supplies when traveling with their babies. My friend speculated that this may be a reaction to the stress of traveling with an infant. I told her I would look into this, since I couldn't fathom why traveling would make a mom's milk supply decrease. A mom's milk supply could surely decrease when traveling WITHOUT her infant, but why WITH her infant? After some internet and article searching, I couldn't find any scientific reasons that would cause this phenomenon. But, since a few moms have seen this happen, I thought I would offer some advice on how to make sure that this doesn't happen to you.