Some do it in the womb, some do it right after birth, some never do it at all. Whichever the case, babies clearly start life with a natural urge to suck. Almost all babies plop a thumb, fist, finger, or pacifier in their mouth at some point during the first year. In fact, a recent study on the use of sleep aids from the University of California, Davis, found that almost all infants used something to help them at bedtime. Three-month-olds preferred thumbs, fingers, or hands, whereas 6-month-olds went for soft objects such as pacifiers. Experts say there are benefits from this "nonnutritive sucking", including the following:
- It satisfies a baby's normal sucking reflex.
- Sucking creates a soothing effect, which helps lull a child to sleep, or calms her when she's upset.
- Using their mouths is the primary way infants learn about the world.
When it comes to a pacifier versus a thumb, it seems pediatricians are divided on which is better for your child. Some say pacifiers are less likely to lead to dental problems since pacifiers are more flexible, exerting less pressure on the mouth, and their use can often be stopped earlier. Meanwhile, some studies suggest that babies who use pacifiers are more likely to get ear infections, but that association appears to be negligible if the pacifier is restricted to bedtime. Other research links pacifier use in the first few months to decreased long-term breastfeeding. Also, some babies may develop nipple confusion if a pacifier is introduced before breastfeeding is established.
As for thumbs, experts say babies who use thumb or fingers may be more independent because digits won't ever get lost or fall out of the crib.
Whichever your infant prefers, if he's still sucking at age 2 you might want to begin to break him of the habit, or at least limit how often he does it. For years doctors have touted thumb or pacifier habits as fine until around age 5, but a new study in the December issue of The Journal of the American Dental Association suggests that if the practice continues beyond age 2, a child's bite may be affected, causing misalignment of the teeth. Dr. Mary J. Hayes, a pediatric dentist in Chicago points out that nonnutritive sucking can also lead to speech problems like lisping. Whether or not your child is affected depends largely on the frequency or intensity of her habit. "Some kids just occasionally place the thumb or pacifier in their mouth, but others suck more often or more intensely," she says, and those are the ones to watch. A pediatric dentist can help you determine if your child's sucking is causing problems.