The majority of women lose their sack of water after labor is already in full swing, but occasionally, a woman's waters will break with a gush at the beginning of labor. Amniotic fluid is usually fairly simple to clean up and doesn't leave a stain.
Removing the Stain
The first step in removing the stain is blotting up any excess amniotic fluid, if it hasn't already dried. Apply a small amount of gentle liquid laundry detergent diluted in cold water to the stain with a cloth. Blot the mattress gently, but don't rub it. Amniotic fluid is a protein stain, so treat it as you would blood or urine.
Amniotic fluid is generally colorless and odorless, unless meconium, which is the infant's stool, was present. If an odor persists, try baking soda or an enzymatic cleaner that breaks down stains and odors. Products designed to remove pet stains are usually enzymatic cleaners.
Take the mattress outside, if possible, to air out on a clear, sunny day. Otherwise, open the windows or run a fan to increase ventilation.