1-4 months
1–4 months
Physical
Physical
- Head and chest circumference are nearly equal to the part of the abdomen.
- Head circumference increases approximately 2 cm per month until two months, then increases 1.5 cm per month until four months.
- Increases are an important indication of continued brain growth.
- Continues to breathe using abdominal muscles.
- Posterior fontanelle.
- Anterior fontanelle.
- Skin remains sensitive and easily irritated.
- Legs.
- Cries with tears.
- Gums are red.
- Eyes begin moving together in unison (binocular vision).
- Rooting and sucking reflexes are well developed.
- Swallowing reflex and tongue movements are immature;inability to move food to the back of the mouth.
- Grasp reflex.
- Landau reflex appears near the middle of this period; when baby is held in a prone (face down) position, the head is held upright and legs are fully extended.
- Grasps with entire hand; strength insufficient to hold items. Holds hands in an open or semi-open position.
- Movements are large and jerky.
- Raises head and upper body on arms when in a prone position.
- Turns head side to side when in a supine (face up) position;can not hold head up and line with the body.
- Upper body parts are more active: clasps hands above face, waves arms about, reaches for objects.