Lifespan Development. Tara L. Kuther

current birthing practices?

      The Newborn

      The average newborn is about 20 inches long and weighs about 7½ pounds. Boys tend to be slightly longer and heavier than girls. Newborns have distinctive features, including a large head (about ¼ of body length) that is often long and misshapen from passing through the birth canal. The newborn’s skull bones are not yet fused—and will not be until about 18 months of ag—permitting the bones to move and the head to mold to the birth canal, easing its passage. A healthy newborn is red-skinned and wrinkly at birth; skin that is bluish in color indicates that the newborn has experienced oxygen deprivation. Some babies emerge covered with lanugo, the fuzzy hair that protects the skin in the womb; for other babies, the lanugo falls off prior to birth. The newborn’s body is covered with vernix caseosa, a waxy substance that protects against infection; this dries up within the first few days. Although many hospital staff wash the vernix caseosa away after birth, research suggests that it is a naturally occurring barrier to infection and should be retained at birth (Jha et al., 2015).

      Medical and Behavioral Assessment of Newborns

      After birth, newborns are routinely screened with the Apgar scale, which provides a quick and easy overall assessment of the baby’s immediate health. As shown in Table 3.1, the Apgar scale is composed of five subtests: appearance (color), pulse (heart rate), grimace (reflex irritability), activity (muscle tone), and respiration (breathing). The newborn is rated 0, 1, or 2 on each subscale for a maximum total score of 10. A score of 4 or lower means that the newborn is in serious condition and requires immediate medical attention. The rating is conducted twice, 1 minute after delivery and again 5 minutes after birth; this timing ensures that hospital staff will monitor the newborn over several minutes. Over 98% of all newborns in the United States achieve a 5-minute score of 7 to 10, indicating good health (Martin, Hamilton, Osterman, Curtin, & Mathews, 2013).

      The Brazelton Neonatal Behavioral Assessment Scale (NBAS) is an neurobehavioral assessment commonly administered to newborns, especially those who are judged to be at risk (Bartram, Barlow, & Wolke, 2015). It is administered in the first few days after birth to assess the newborn’s neurological competence as indicated by the responsiveness to the physical and social environment, perception, and motor skills such as activity level and the ability to bring a hand to the mouth (Nugent, 2013). The NBAS also assesses infants’ attention and state changes, including excitability and ability to settle down after being upset. When parents observe and participate in their baby’s NBAS screening, they learn about their newborn’s perceptual and behavioral capacities and are better able to elicit gazes, quiet fussiness, and tend to be more responsive to their infants (Benzies et al., 2013).

      The Newborn’s Perceptual Capacities

      Until recent decades, it was widely believed that the newborn was perceptually immatur—blind and deaf at birth. Developmental researchers now know that the newborn is more perceptually competent than ever imagined. For example, both taste and smell are well developed at birth. Taste appears to function well before birth because research has shown that fetuses swallow sweetened amniotic fluid more quickly than bitter fluid (Ventura & Worobey, 2013). Newborns can discriminate smells and calm in response to the scent of amniotic fluid and other familiar smells (Neshat et al., 2016; Rotstein et al., 2015) The visual capacities of the newborn are more limited and focused primarily on the near environment. Newborn vision is blurry and best at about 18 inches away—the typical distance to a parent’s face when holding the infant.

      The most remarkable newborn capacities for perception and learning are auditory in nature. Pregnant women often report that they notice fetal movements in response to a loud sound like a car horn or a door slamming. The fetus responds to auditory stimulation as early as 23 to 25 weeks after conception (Hepper, 2015). By 32 to 34 weeks, the fetus responds to the mother’s voice as indicated by a change in heart rate (Kisilevsky & Hains, 2011). Prior to birth, the fetus can discriminate voices and speech sounds (Granier-Deferre, Ribeiro, Jacquet, & Bassereau, 2011). At birth, newborns show preferences for speech sounds, their mother’s voice, their native language, and even stories and music heard prenatally (Moon, Cooper, & Fifer, 1993). Moreover, from birth, the newborn is an active listener, paying attention to sounds and naturally taking advantage of opportunities to learn (Vouloumanos, Hauser, Werker, & Martin, 2010).

      Table 3.1

      Source: Apgar (1953).

      Newborn States of Arousal

      Newborns display regular cycles of eating, elimination, and states of arousal or degrees of wakefulness. In a typical day, newborns move in and out of six infant states or levels of arousal, as shown in Table 3.2. Most newborns spend about 70% of their time sleeping and wake every 2 to 3 hours. These short stretches of sleep alternate with shorter periods of wakefulness that are primarily devoted to feeding. During the first month, infants often move rapidly from one state to another, dozing off during feeding, for example. Naps are punctuated by periods of drowsiness, alert and inalert activity, and crying.

      Newborn sleep cycles are brief, lasting from 45 minutes to 2 to 3 hours, but similar to those of adults in that they consist of both REM sleep, or rapid eye movement (REM) sleep, and non-REM sleep (Korotchikova, Stevenson, Livingstone, Ryan, & Boylan, 2016). When a person is in REM sleep, the brain wave activity is remarkably similar to that of the waking state. The eyes move back and forth beneath closed lids; heart rate, blood pressure, and breathing are uneven; and there are slight body movements. It is sleep. Newborns spend about half of their sleep time in REM, but by ages 3 to 5, children spend about 15% to 20% of their sleep in REM, similar to adults (Grigg-Damberger & Wolfe, 2017; Kobayashi, Good, Mamiya, Skinner, & Garcia-Rill, 2004).

      Why do newborns spend so much time in REM sleep? REM sleep is associated with dreaming in both children and adults. Neonates spend about 18 hours sleeping each day and therefore spend little time in the active alert state in which they get stimulation from the environment. REM is a way that the brain stimulates itself, which is important for the growth of the central nervous system (Grigg-Damberger & Wolfe, 2017). This view of REM sleep as serving a self-stimulation function is supported by findings that fetuses and preterm babies, who are even less able to take advantage of external stimulation than are newborns, spend even more time in REM sleep. In addition, neonates with low REM sleep activity tend to score lower on mental tests at 6 months of age (Arditi-Babchuk, Feldman, & Eidelman, 2009).

      Low-Birthweight Infants: Preterm and Small-for-Date Babies

      About 8% of infants born in the United States each year are low birthweight (Martin et al., 2013). Low-birthweight infants may be preterm, or premature (born before their due date), or small for date, who are full term but have experienced slow growth and are smaller than expected for their gestational age. Infants are classified as low birthweight when they weigh less than 2,500 grams (5.5 pounds) at birth; very low birthweight refers to a weight less than 1,500 grams (3.5 pounds), and extremely low birthweight refers to a weight less than 750 grams (1 lb., 10 oz.). Infants who are born with low birthweight are at risk for a variety of developmental difficulties. Indeed, their very survival is far from certain; the Centers for Disease Control and Prevention lists prematurity and low birthweight among the leading causes of infant mortality, accounting for 35% of mortality cases in infancy (Mathews & MacDorman, 2013). Infants most at risk for developmental challenges, handicaps, and difficulty surviving are those with extremely low birthweight. As shown in Figure 3.10, women of color are disproportionately likely to give birth to low-birthweight infants. The socioeconomic inequalities that influence women’s ability to seek early prenatal care also influence birth outcomes. Unfortunately, poor access to health care can prevent low-birthweight infants from getting the help that they need to overcome the formidable challenges ahead of them.