DEve.pdf

# Developmental Psychology Notes ## The newborn baby - **Neonatal period** - first four weeks of life, a time of transition from intrauterine dependency to independent existence. - In their first few days, neonates lose as much as 10 percent of their body weight, primarily because of a loss of flu...

# Developmental Psychology Notes ## The newborn baby - **Neonatal period** - first four weeks of life, a time of transition from intrauterine dependency to independent existence. - In their first few days, neonates lose as much as 10 percent of their body weight, primarily because of a loss of fluids. - They begin to gain weight again at about the fifth day and are generally back to birth weight by the tenth to the fourteenth day. - New babies have distinctive features, including a large head (one-fourth the body length) and a receding chin (which makes it easier to nurse). - At first, a neonate's head may be long and misshapen because of the molding that eased its passage through the mother's pelvis. This temporary molding occurs because an infant's skull bones are not yet fused; they will not be completely joined for 18 months. - The places on the head where the bones have not yet grown together - the fontanels, or soft spots - are covered by a tough membrane. ## Body Systems - Before birth, blood circulation, respiration, nourishment, elimination of waste, and temperature regulation are accomplished through the mother's body. - After birth, all of the baby's systems and functions must operate on their own. Most of the work of this transition occurs during the first four to six hours after delivery. - The fetus and mother have separate circulatory systems and separate heartbeats; the fetus's blood is cleansed through the umbilical cord, which carries used blood to the placenta and returns a fresh supply. - A neonate's blood circulates wholly within the baby's body. The heartbeat at first is fast and irregular, and blood pressure does not stabilize until about ten days after birth. - The fetus gets oxygen through the umbilical cord, which also carries away carbon dioxide. - A newborn needs much more oxygen than before and now must get it alone. Most babies start to breathe as soon as they are exposed to air. If breathing has not begun within about five minutes, the baby may suffer permanent brain injury caused by anoxia, lack of oxygen, or hypoxia, a reduced oxygen supply. - Because infants' lungs have only one-tenth as many air sacs as adults' do, infants (especially those born prematurely) are susceptible to respiratory problems. - Anoxia or hypoxia may occur during delivery (though rarely so) as a result of repeated compression of the placenta and umbilical cord with each contraction. This form of birth trauma can leave permanent brain damage, causing mental retardation, behavior problems, or even death. - In the uterus, the fetus relies on the umbilical cord to bring food from the mother and to carry fetal body wastes away. - At birth, babies instinctively suck to take in milk, and their own gastrointestinal secretions digest it. - During the first few days infants secrete meconium, a stringy, greenish-black waste matter formed in the fetal intestinal tract. - When the bowels and bladder are full, the sphincter muscles open automatically; a baby will not be able to control these muscles for many months. ## Medical and Behavioral Assessment - **Apgar Scale** - Standard measurement of a newborn's condition; it assesses appearances, pulse, grimace, activity, and respiration. - One minute after delivery, and then again five minutes after birth. - The newborn is rated 0, 1, or 2 on each measure, for a maximum score of 10. - A score below 7 means the baby needs help to establish breathing; a score below 4 means the baby needs immediate lifesaving treatment. - **Brazelton Neonatal Behavioral Assessment Scale (NBAS)** - Neurological and behavioral test to measure neonate's responses to the environment. - Health care providers, and researchers assess neonates' responsiveness to their physical and social environment, to identify strengths and possible vulnerabilities in neurological functioning, and to predict future development. - It assesses motor organization, as shown by such behaviors as activity level and the ability to bring a hand to the mouth; reflexes; state changes, such as irritability, excitability, and ability to quiet down after being upset; attention and interactive capacities, as shown by general alertness and response to visual and auditory stimuli; and indications of central nervous system instability, such as tremors and changes in skin color. - The NBAS takes about 30 minutes, and scores are based on a baby's best performance. ## State of Arousal - An infant's physiological and behavioral status at a given moment in the periodic daily cycle of wakefulness, sleep, and activity. - Babies have an internal clock that regulates their daily cycles of eating, sleeping, and elimination and perhaps even their moods. - Most new babies sleep about 75 percent of their time - up to 18 hours a day - but wake up every 3 to 4 hours, day and night, for feeding (Ferber & Makhoul, 2004; Hoban, 2004). - Newborns' sleep alternates between quiet (regular) and active (irregular) sleep. - Active sleep is probably the equivalent of rapid eye movement (REM) sleep, which in adults is associated with dreaming. Active sleep appears rhythmically in cycles of about 1 hour and accounts for up to 50 percent of a newborn's total sleep time. - The amount of REM sleep declines to less than 30 percent of daily sleep time by age 3 and continues to decrease steadily throughout life. ## Complications of Childbirth ### Low birth weight - **Preterm** - infants born before completing 37th week of gestation. - **Small-for-date infants** - infants whose birth weight is less than that of 90 percent of babies of the same gestational age, as a result of slow fetal growth. - Weight of less than 5½ pounds (2,500 grams) at birth because of prematurity or being small for date. - Who is likely to have a low-birth-weight baby? ## Immediate treatment and outcomes - The most pressing fear regarding very small babies is that they will die in infancy. Because their immune systems are not fully developed, they are especially vulnerable to infection, which has been linked to slowed growth and developmental delays (Stoll et al., 2004). - Also, these infants' nervous systems may be too immature for them to perform functions basic to survival, such as sucking, so they may need to be fed intravenously (through the veins). Feeding them breast milk can help prevent infection (AAP Section on Breastfeeding, 2005; Furman, Taylor, Minich, & Hack, 2003). - Because they do not have enough fat to insulate them and to generate heat, it is hard for them to stay warm. - Low Apgar scores in a preterm newborn are a strong indication of the need for intensive care (Weinberger et al., 2000). - **Kangaroo care** - method of skin-to-skin contact which a newborn is laid face down between the mother's breasts for an hour or so at a time after birth. ## Postmaturity - Referring to a fetus not yet born as of 2 weeks after the due date or 42 weeks after the mother's last menstrual period. ## Stillbirth - Death of a fetus at or after the 20th week of gestation. ## Can a Supportive Environment Overcome Effects of Birth Complications? - From an evolutionary standpoint, people - like other organisms - thrive, reproduce, and survive in environments suitable to their needs and expectations. - Thus, appropriate environmental characteristics can help an infant develop optimally. Furthermore, human beings are adaptable, especially during the early years. - A major longitudinal study suggests that, given a supportive environment, resilience can occur even in the face of a difficult start in life. ## Protective factors - Influences that reduce the impact of potentially negative influences and tend to predict positive outcomes. 1. Individual attributes. 2. Affectionate ties with at least one supportive family member. 3. Rewards at places that provide a sense of meaning and control over one's life. ## Early physical development 1. **Cephalocaudal principle** - Principle that development proceeds in a head-to-tail direction, that is, that upper parts of the body develop before lower parts of the trunk. - Infants learn to use the upper parts of the body before the lower parts.