One very effective trick (in hospitals that insist that mothers labor on "clear liquids only") is to have the mother take along a zippy bag of "labor cubes" to the hospital, storing them in her room fridge. "Labor Cubes" are ice cubes made out of very strong raspberry leaf tea (perhaps one cup herb to one quart water, simmered down to half and strained) that is heavily sweetened with honey. If the laboring mother begins to fade, energy petering out or contractions waning due to lack of nutrition, she can chomp on these satisfying slushy cubes, which usually will perk her up and kick in some great contractions in a matter of minutes.
— Beth Barbeau
Excerpted from "Tricks of the Trade: Liquids Only," Midwifery Today, Issue 81