The Startle (Moro) Reflex
As newborns develop, they exhibit a behavior called the Moro reflex, also called the startle reflex. Although this normal behavior signals a healthy nervous system, it’s called the startle reflex for a reason. It’s often seen when babies are placed on their backs to sleep. Although this is the correct position, it causes them to feel like they’re falling, and their response is to startle in alarm.
When a baby startles from the Moro reflex, arms and legs flail dramatically and they cry, waking them from sound sleep. To keep babies from startling and help them get the rest they need, doctors, midwives, doulas, and other professionals recommend swaddling.
How Swaddling Helps
Swaddling has many benefits. It inhibits the startle reflex by keeping an infant’s limbs snugly close to the body with gentle pressure. When babies are swaddled, they feel more secure, flail less, and sleep better. Babies are typically swaddled from the time they’re newborns until they’re four to six months of age.
Many healthcare professionals and sleep consultants recommend swaddles that hold babies’ arms folded to the chest. There are three specific benefits to keeping an infant’s arms in this comfortable, fetal-like position.
Promotes a Feeling of Security
The swaddle replicates the conditions felt by a baby in the womb. Warm, gentle pressure and the semi-fetal position work to calm infants and help them relax.
Bringing the hands to the body’s midline supports the brain in making the connection between right and left.
Stimulates the Sense of Touch
Skin is the largest organ in our body, and fingertips are one of the most sensitive areas. There are as many as 100 pressure receptors in one cubic centimeter of skin in the fingertips. Swaddling the arms to the midline of the body allows for finger play, and this stimulates those touch receptors.