PHYSICAL DEVELOPMENT IN INFANTS Infants grow rapidly during the first two years of life. During the first year, much time is spent coordinating motor skills. At the end of the first year, an infant will have tripled its birth weight and added 10” to its height.

From 0 – 12 months… What does that kind of growth mean? An infant that weighed 7 ½ lbs and was 20 inches long (an ‘average’ baby) will weigh 22 lbs and be 30 inches long at the end of year. This one of the most accelerated growth stages. The only other time a child will grow and develop that quickly is during adolescence!

Reflexes At birth, the infant’s physical abilities are limited to reflexes—an automatic body response to a stimulus. Doctors use reflexes to assess brain and nerve development. Some reflexes are needed for survival, others are just a sign that all systems are functioning!

Rooting Reflex When something brushes an infant’s cheek, this reflex causes them to turn their heads and suck. This reflex insures the baby’s survival—by insuring the baby will eat. This is the first reflex to disappear.

Moro Reflex This reflex is also referred to as the “startle” reflex. It occurs when a newborn is startled by a noise or sudden movement. The infant reacts by flinging his arms and legs outward and extending his head, then drawing his arms together and crying. This usually disappears after the first two months.

Palmar Grasp Reflex When an infant’s palms are touched, his hands will grip tightly. The grip is strong enough to lift them with, but DON’T! This reflex disappears after 3 or 4 months.

Babinski Reflex This reflex is present at birth for full term infants. To test for this reflex, stroke the sole of an infant’s foot from heel to toe. The toes will fan out and curl. This reflex usually lasts for the first year after birth.

Stepping or Walking Reflex This reflex can be observed in full-term babies. When an infant is held so its feet are flat on a surface, the infant will lift one foot after the other in a stepping motion. This reflex disappears after about the 2nd month, but will recur as learned behavior toward the end of the first year.