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. - Neonates lose as much as 10 percent of their body weight in the first few days, primarily because of a loss of fluids...

# Developmental Psychology Notes ## The Newborn Baby - **Neonatal period** - First four weeks of life, a time of transition from intrauterine dependency to independent existence. - Neonates lose as much as 10 percent of their body weight in the first few days, 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. - A neonate's head may be long and misshapen at first 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; 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. ## The layers of fat that develop during the last two months of fetal life enable healthy full-term infants to keep their body temperature constant after birth despite changes in air temperature. ## 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. - 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? ## 1. Demographic and socioeconomic factors ## 2. Medical factors predating the pregnancy ## 3. Prenatal behavioral and environmental factors ## 4. Medical conditions associated with the pregnancy ## 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. - 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. - 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. - **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.