Your Baby’s Physical Development
Your baby’s physical development happens in three main areas: muscles, senses, and perception.
Your baby’s movements involve various muscle groups working together, reflexively at first, and then more consciously as she discovers she has the power to move herself. Movements fall into three main categories:
Reflexes are automatic, involuntary responses to a stimulus. Some reflexes occur only in infancy. The following reflexes indicate normal brain and nerve development in your baby.
- Rooting and Sucking Reflex: When an object brushes your baby’s face or lips, she begins sucking. This survival reflex helps her find food at birth. It disappears after three weeks.
- Palmar Grasp Reflex: When a finger or toy comes into contact with your baby’s palm, she grips the object tightly. This reflex disappears after three or four months.
- Stepping or Walking Reflex: When you hold your infant so her feet are flat on a surface, she puts one foot in front of the other in a stepping motion. This reflex disappears after two months and reappears at the end of her first year as she begins to walk.
- Moro (Startle) Reflex: When your baby hears a loud noise, sees a sudden movement, or suddenly feels unsupported, her head falls back and her arms and legs curve upward. She may also cry. This reflex disappears after about two months.
- Babinski Reflex: When you stroke the sole of your baby’s foot from her heel to her big toe, her toes fan out and curl, and her foot twists inward. This reflex disappears after one year.
These skills involve control of the large muscles in your baby’s legs, arms, back, and shoulders. Gross-motor activities include rolling over, sitting, creeping, standing, walking, running, jumping, and climbing.
These skills come as your baby masters the small muscles in her fingers and hands. Fine-motor activities include reaching, grasping, holding, releasing, cutting, drawing, and dressing.
As your baby takes command of her muscles, she is also sharpening her senses. Beginning before your baby was born, senses (touch, taste, smell, hearing, and vision) have been her avenues for taking in information. In utero, she could hear her mother’s heartbeat, voice, and grumbling stomach; taste and smell amniotic fluid; and use her hands and feet to touch and feel in the womb.
A baby’s eyes typically open at about seven months in utero, and ultrasounds have documented that babies open and close their eyes more often as they approach birth. At birth, your baby’s vision is blurry, and her near vision is better than her far vision. She focuses on objects that are 8 to 15 inches in front of her face. She also shows preferences for patterned objects over solids, bold colors over pastels, faces over objects, and smiling faces over faces with other expressions. Her vision develops rapidly, and by three months she can see nearby objects clearly. At about four months, her eyes are working together and can focus equally on objects; she attains binocular vision, three-dimensional vision, depth perception, and the ability to track objects. Within another few months, she can see as well as an adult.
As your baby’s sense of sight improves, so does her hearing. Starting at birth, she turns her head toward sounds and reacts to loud noises. She recognizes her mother’s voice and finds it soothing. Songs and rhythmic sounds calm her and help her fall sleep. As her hearing matures during her first six months of life, she can hear soft sounds, as well as loud ones, and nearby sounds, as well as distant ones. At one year old, her hearing is comparable to an adult’s.
In addition to hearing her mother’s voice before birth, a baby tastes and smells her mother’s food choices in utero. Fetuses drink several ounces of amniotic fluid a day, and this fluid smells and tastes like the food the mother has consumed. According to studies by Julie Mennella and Gary Beauchamp of the Monell Chemical Senses Center, the foods that a mother eats while pregnant and nursing help form her child’s future flavor preferences. So, while you are pregnant and your baby is breast-feeding, you can expose her to a variety of flavors and expand her palate and flavor preferences.
Perception develops as your baby begins using all her senses to recognize and discriminate among objects, sounds, people, and events. She receives information through her senses from her internal and external environment, and then she filters that information. Her perception improves as her senses sharpen and as she becomes capable of paying attention and focusing enough to distinguish one object or sound from another. In her first year, she develops her visual, depth, and auditory perception, as well as her sound differentiation.