It could be vomit or any other thing, but your sofa will surely feel the presence of a new baby. See Tips for cleaning vomit off the sofa:
1. Absorb excess liquid: As soon as the solids are gone, make use of paper towels or clean rags to soak up the liquids that is left.
2. Spray or spritz some soda water: Spray carbonated water on the affected area.
3. Blot again: Blot once more to absorb the new moisture.
4. Sprinkle baking soda: Sprinkle it on the affected area and allow the baking soda to absorb what it can.
5. Scrape or vacuum: A vacuum can now be involved. It will prevent permanent stains and funny smells.