A neonate is a newborn in the first 28 days of life, a period of swift adaptation to the world outside the womb. During this time, the infant undergoes numerous changes, adjusting its bodily systems to new ways of breathing, eating, and regulating temperature. It is a phase of rapid development where the foundations for future growth are established.
Physical Characteristics of a Newborn
A newborn’s appearance is distinct. Many are covered in a waxy, cheese-like substance called vernix caseosa, which protected their skin from amniotic fluid in the womb. This coating also provides a barrier against infection after delivery and gradually absorbs into the skin.
Another common feature is lanugo, a coat of fine, downy hair that may cover the shoulders, back, and forehead. This hair helped regulate the baby’s temperature in the uterus and sheds within the first few weeks of life. The presence and amount of both vernix and lanugo can vary, with premature babies often having more than full-term infants.
A newborn’s head may appear elongated or cone-shaped, a result of molding, where the skull bones shift to navigate the birth canal. This is possible because of fontanelles, the soft spots on the head where the skull bones have not yet fused. These flexible areas allow for the rapid brain growth that occurs during infancy. The stump of the umbilical cord remains attached, which dries up and falls off on its own within one to three weeks.
Innate Reflexes and Behaviors
Newborns are equipped with involuntary reflexes, which are automatic responses to stimuli that help them survive. These primitive reflexes are indicators of a healthy nervous system. For example, the rooting reflex is triggered when a baby’s cheek is stroked; they will turn their head toward the touch and open their mouth, a behavior that helps them find a food source.
Closely related is the sucking reflex, which prompts the baby to suck when the roof of their mouth is touched. This reflex begins to develop around the 32nd week of pregnancy. Another is the Moro reflex, or startle reflex, where a loud noise or sudden movement causes the baby to throw back their head, extend their arms and legs, and then pull them back in.
The palmar grasp is another reflex, where stroking a baby’s palm causes them to close their fingers and grip tightly. Neonatal behaviors are also characterized by disorganized sleep-wake cycles spread throughout the day and night. Crying is their primary form of communication, with different cries signaling needs such as hunger, discomfort, or fatigue.
Sensory Development and Perception
A neonate’s senses are functional at birth. Hearing is one of the most developed senses; newborns have been hearing sounds in the womb for months and can recognize and show a preference for their mother’s voice shortly after birth. Their sense of smell is also acute, enabling them to identify their mother’s unique scent, which can be a source of comfort.
Vision, however, is the least developed sense at birth. A newborn’s sight is blurry, with their clearest focus limited to objects about 8 to 12 inches away—roughly the distance to a caregiver’s face during feeding. They are most responsive to high-contrast patterns, such as black and white images, and are naturally drawn to look at human faces.
The senses of touch and taste are also mature at birth. Newborns are highly responsive to touch and can feel changes in temperature and texture. Their preference for sweet tastes is well-established, which is why they readily accept breast milk or formula.
Initial Health and Wellness Checks
After birth, newborns undergo health assessments to ensure they are transitioning well, the first of which is the APGAR score. This quick evaluation is performed at one and five minutes after delivery and assesses five indicators: appearance (skin color), pulse (heart rate), grimace (reflex irritability), activity (muscle tone), and respiration (breathing effort). The total score provides a snapshot of the baby’s overall condition.
To prevent a rare but serious bleeding disorder, nearly all newborns receive a vitamin K injection. Infants are born with low levels of vitamin K, which is necessary for blood clotting, and this shot provides protection until their bodies can produce it. Another preventative measure is the application of antibiotic eye ointment to protect against infections contracted during passage through the birth canal.
Before leaving the hospital, two screenings are performed. A hearing screening checks for potential hearing loss, allowing for early intervention if needed. The newborn metabolic screening, often called the “heel prick test,” involves taking a small blood sample from the baby’s heel to test for dozens of rare but serious conditions that may not be apparent at birth.