Umbilical Cord Care Basics
Keep your baby's umbilical cord area as clean and dry as possible. Folding down the top of the diaper to leave the cord exposed is a good idea and will prevent urine from soaking the cord area. You can also buy special diapers with an indented top seam.
It is important to avoid binding the mid-abdominal area with a bandage or cloth, as is common in some cultures. This keeps moisture in and promotes the growth of germs. Very tight clothing can potentially do this as well, so be sure to dress your baby in loose clothes that won't rub against the cord and potentially irritate the stump while it heals (onesies are fine as long as they are loosely worn.)
As the umbilical stump decays in preparation for detachment, the tissue begins to look yellow and may smell. This is OK. But, what isn't OK and may signal an impending infection (which can get very serious very quickly) are the following signs: frank pus at the cord site, reddening of the skin around the insertion site, or obvious tenderness when the area is touched. Any of these signs demands an immediate call to the pediatrician.
After the cord stump detaches (be sure to let it fall off on its own; pulling it off is not advised), the remaining tissue will still appear moist for a few more days. Alcohol wipes should be used until the area becomes completely dry.
On occasion, a small, wet, reddish mass persists after the cord falls off, which may or may not ooze a yellowish material. This is most likely a granuloma, which requires an application of a chemical called silver nitrate at the doctor's office, but which almost always shrinks with this treatment.
Once the cord is off and the umbilical area looks dry and well-healed, special attention is no longer required. Now your baby can safely get into his infant tub for his first immersion bath and you can gently wash that cute little belly button.