The purpose of a message written in baby shower card is to provide a greeting to the new baby, but also to provide the parents with a congratulations message that will increase their joy, and be something that can be kept long-term as a remembrance of the occasion. Some ideas of what to write in a baby shower card include messages that relate to the baby shower itself, or that depict a simple happiness or welcome for the baby that will soon arrive.
Hallmark gives some additional ideas, such as messages that relate to the baby being a boy or a girl, or possibly multiple babies, and also messages about the baby being the first baby in the family, or whether the baby is an addition to a family that already has children.
A card could show your excitement about the new baby. For instance, the message could say “Can’t wait to see that sweet little smile.” Hallmark also offers ideas for writing messages if the situation is an adoption. For example, the card's message could say “This precious little boy was meant for you and you for him. Warmest congratulations to your beautiful family.” The message could be humorous. For example, a message could say "Hello, cutie-pie! Bye-bye sleep!"