About the program:
These messages are timed to your due date or your baby’s birth date. If you are pregnant and your due date changes, text UPDATE to 511411 to enter your new due date. Once you have your baby, be sure to text in UPDATE with your baby’s birthday so you keep getting messages through baby’s first year.
If you want to stop receiving messages from text4baby, text STOP to 511411. To start receiving the messages again, you will have to enroll again by sending BABY to 511411 (BEBE to 511411 for Spanish messages). Source text4baby.org