Size may not matter, but how you clean your baby's penis does. There are very different methods for cleaning a circumcised penis versus an uncircumcised one.
How to: If your baby boy is circumcised, submerging him in bathwater before the wound heals could subject him to infection, warns Dr. Dull, so clean with care. After he's circumcised, his penis will be wrapped in gauze -- wait for the gauze to fall off on its own before you clean him up.
Wipe the penis very gently with a soft, wet, soapy cloth, and don't forget to lift the scrotum and clean the base. Then, coat the wound with triple antibiotic ointment, which keeps it clean, helps it heal, and prevents it from sticking to the diaper. Use the ointment until the skin's tone is even with the rest of the penis.
Uncircumcised babies can take baths as soon as the umbilical cord falls off, but don't pull the foreskin down, advises Dr. Dull. The membrane attaching it to the penis will tear and bleed if it's tugged too hard. It takes four months to a year before you can clean inside, she says. "When you can gently and easily pull it back, it's time to clean inside." Until then, clean the outside of the penis with a soft cloth, soap, and water.
This is probably the easiest part about raising girls -- your baby's vagina is virtually self-cleaning. "Unless you're dealing with feces in the labia, it requires only a superficial cleaning, without a lot of pressure or rubbing," says Bruce Eisenberg, MD, a pediatrician and homeopath in private practice in Miami. "The vagina secretes out most of what doesn't belong inside."
How to: Cover your finger with a clean, wet washcloth and gently pat along the creases and folds. "You don't want a lot of soap in there because it will irritate," says Dr. Eisenberg. "And there's no need to spread the labia apart." After you wash, pat your child dry.