The Ins and Outs of Thumb-Sucking
Studies show that 50 percent to 70 percent of children have a thumb-sucking habit during their first year. Thumb-sucking often begins as early as the 29th week of gestation, and most children spontaneously stop the habit by age 4 or 5.

Here's what you should know about thumb-sucking:

• It is a reflexive response to any nipple-shaped object brushing the cheek or lips.

• It satisfies the child’s need for oral stimulation, and it is a natural, normal way that children soothe themselves.

• Infants explore their world primarily through the mouth.

• Prior to age 5, thumb-sucking is acceptable if the habit stops before the permanent teeth emerge. Thumb-sucking rarely affects speech.

To Pacify or Not to Pacify?
Pacifiers are similar to thumbs in providing the comfort of sucking. Children generally stop using a pacifier by age 3, so it rarely causes dental problems. There are, however, several disadvantages to pacifier usage:

• It can affect speech development, because children who use pacifiers often try to speak with the pacifier in their mouths.

• Children drop pacifiers frequently, potentially transporting infectious germs to themselves.

If you’re breastfeeding your baby, do not introduce a pacifier until lactation is well established. Also, don’t introduce it to a baby who isn’t gaining weight adequately or who is nursing poorly – she may lose interest in breastfeeding.

For more about the Pacifier vs. the Thumb, check out:

Pacifiers: Why, When, Where and How
All Thumbs