In contrast to the rapid growth that occurs during infancy, a child’s growth rate slows down during early childhood development. Physical growth does not increase steadily during this stage. Instead, it typically occurs in spurts.

Babies usually gain between 3 and 5 pounds (1.4 and 2.3 kilograms) during the second year of life. Most 2-year-olds are about 34 inches (86 centimeters) tall and weigh about 27 to 28 pounds (12.3 to 12.7 kilograms). Boys tend to weigh slightly more than girls.

From ages 2 to 4 years, most children gain about 4 to 5 pounds (1.8 to 2.3 kilograms) in weight and 2 to 3 inches (5 to 8 centimeters) in height each year. Head size increases only by about 1 inch (2.5 centimeters) in circumference during early childhood.

Appetite typically decreases during this stage, and a child’s weight may remain the same for weeks at a time. As body fat steadily decreases during early childhood, children gain muscle tone and have a leaner, more muscular body appearance by age 4.

Toddlers usually have protruding abdomens when standing, and an inward curvature of the lower spine called lumbar lordosis. Increases in height during early childhood result primarily from growth of the lower extremities and, to a lesser extent, elongation of the trunk. Growth of a child’s lower extremities often is accompanied by a bowing of the legs. Parents should not be concerned by either lumbar lordosis or their child’s bowed-legged appearance because they typically correct themselves by a child’s third birthday. Throughout childhood, a pediatrician will continue to monitor a child’s growth in weight and height, and check for any abnormalities or growth delays.

Growth during early childhood also may be accompanied by growing pains. This is a normal occurrence that may affect children ages 3 to 5 years. Pain often affects the muscles of both legs, and may vary in intensity and duration. Children usually experience growing pains at night, and symptoms generally go away by morning.

By age 2, vision is fully developed. Most healthy children have 20/20 vision and can see details as well as all colors. A child’s hand preference is also well established at this time.

All primary teeth typically have emerged by age 3. The American Dental Association (ADA) recommends that beginning at age 3, children use toothpaste that contains fluoride to support healthy teeth and gums. In addition to routinely brushing teeth with fluoridated toothpaste, children can decrease risk of cavities by drinking water with fluoride.

Most 3-year-olds, especially girls, have control over their bowel and bladder functions during the day. Nighttime control usually occurs slightly later. Parents and other caregivers may start toilet training their toddlers as early as age 2, although some may wait until a child’s third birthday. Bedwetting is normal up to age 4 in girls and 5 years in boys.