A congratulations card for a new baby should include a personal note expressing well wishes for the family and the baby. The note does not need to be long. One or two lines is enough to let the family members know you are thinking of them and wish them well.
The relationship with the new parents influences the type of message appropriate for the congratulations card. General well wishes work for acquaintances who are not personally close. Well wishes for a close friend or family member often have a more personal message. This might include an inside joke, favorite memory or other shared knowledge.
Simple wording creates a personalized message for the family. Including the baby's name or gender if the name is known shows thought. An example is, "Congratulations on the birth of your healthy baby girl!" If the family posted pictures, or you've visited the baby already, one option is to reference the baby's appearance, such as "Your beautiful baby boy looks so much like his mommy!"
Another option is to include a little humor in the baby well wishes. New parents are often busy and tired. A funny note is a simple way to bring smiles to their faces. Ideas include referencing all the dirty diapers or late nights.