Exam 1 Chapter 2 Prenatal development & the newborn
Apply knowledge about the risks of being low-birth-weight, and research on the factors that improve outcomes, to cases of individual infants.
-Infants who weigh less than 5½ pounds (2500 grams) at birth are considered to be of low birth weight (LBW). -As a group, LBW newborns have a heightened level of medical complications, as well as higher rates of neurosensory deficits, more frequent illness, lower IQ scores, and lower educational achievement. what happens when all of these qualities are not present? -The bad news is that, as a group, children who were LBW infants have a higher incidence of developmental problems: the lower their birth weight, the more likely they are to have persistent difficulties (e.g., Muraskas, Hasson, & Besinger, 2004). They suffer from somewhat higher levels of hearing, language, and cognitive impairments. In preschool and elementary school, they are more likely to be distractible and hyperactive and to have learning disabilities. This group is also more likely to experience a variety of social problems, including poor peer and parent-child relations (Landry et al., 1990). Finally, adolescents who were LBW babies are less likely than their siblings to complete high school (Conley & Bennett, 2002). This result holds even within twin pairs; the twin with higher birth weight is more likely to complete high school than is his or her smaller co-twin (Black et al., 2007). -The good news is that the majority of LBW children turn out quite well. The negative effects of their birth status gradually diminish, with children who were slightly to moderately underweight as newborns generally ending up within the normal range on most developmental measures -A variety of intervention programs for LBW newborns offer a prime example of our theme about the role of research in improving the welfare of children. In many of them, parents are active participants, -To compensate for this lack of everyday touching experience, Field and her colleagues (Field, 2001; Field, Hernandez-Reif, & Freedman, 2004) developed a special therapy that involves massaging LBW babies and flexing their arms and legs (Figure 2.24). LBW babies who receive this therapy are more active and alert and gain weight faster than those who are not massaged. As a consequence, they get to go home earlier. Recent results also suggest that having parents sing to their LBW newborns during their stay in the hospital similarly improves the newborns' health, while also calming parents' fears -how the child plays an active role in their own development. interested in what can help lbw infants and low ses families. -zeskind & ramey (1979) -infants from low income families -half VLBW (very low birth weight) and half were typical -intervention programs for infants 1/2 of vlbw and half of other went into intervention, other was control. -One step that can be helpful to parents of an LBW or preterm infant is learning more about infant development. One intervention program trained mothers—in the hospital and after returning home—to interpret their preterm babies' signals (Achenbach et al., 1990). When tested at age 7 years, their children showed significantly better cognitive skills than those of a comparison group of LBW children whose parents did not receive training. -social support - -measured DQ (developmental quotient)/IQ (intelligence quotient) should be about 100 and maternal responsiveness
Describe the prenatal effects of various maternal factors and teratogens, and how the effects depend on other factors, especially timing of exposure.
-The most common teratogens in the United States are cigarette smoking, alcohol consumption, and environmental pollution. Maternal factors (malnutrition, illness, stress, and so forth) can also cause problems for the developing fetus and child. -cigs - When a pregnant woman smokes a cigarette, she gets less oxygen, and so does her fetus. Indeed, the fetus makes fewer breathing movements while its mother is smoking. In addition, the fetuses of smokers metabolize some of the cancer-causing agents contained in tobacco. And because the mother-to-be inhales cigarette gases when someone else is smoking nearby, secondhand smoke has an indirect effect on fetal oxygen. -fetal alcohol spectrum disorder (FASD) the harmful effects of maternal alcohol consumption on a developing fetus. Fetal alcohol syndrome (FAS) involves a range of effects, including facial deformities, mental retardation, attention problems, hyperactivity, and other defects. Fetal alcohol effects (FAE) is a term used for individuals who show some, but not all, of the standard effects of FAS. -Timing is crucial for exposure to many teratogens; the severity of effects is also related to the amount and length of exposure, as well as to the number of different negative factors with which a fetus has to contend -Many teratogens cause damage only if they are present during a sensitive period in prenatal development. The major organ systems are most vulnerable to damage at the time when their basic structures are being formed. Because the timing is different for each system, the sensitive periods are different for each system. -The most sensitive or critical period of prenatal development is the embryonic period. During the first 2 weeks, before implantation in the uterus, the zygote is generally not susceptible to environmental factors. Every major organ system of the body undergoes all or a major part of its development between the 3rd and the 9th week. -maternal factors: -age:Infants born to girls 15 years or younger are three to four times more likely to die before their first birthday than are those born to mothers who are between 23 and 29 -nutrition: general malnutrition affects the growth of the fetal brain: newborns who received inadequate nutrients while in the womb tend to have smaller brains containing fewer brain cells than do well-nourished newborns. -maternal emotional state: maternal anxiety and depression during pregnancy were assessed. The higher the level of distress the pregnant women reported, the higher the incidence of behavior problems in their children at 4 years of age—including hyperactivity and inattention in boys, conduct problems in girls, and emotional problems in both boys and girls
Understand and explain the basic progression of prenatal development - the 3 major periods and the types of structural changes that occur during each.
1. germinal- Conception to 2 weeks- Begins with conception and lasts until the zygote becomes implanted in the uterine wall. Rapid cell division takes place. 2. embryonic- 3rd to 8th week. Following implantation, major development occurs in all the organs and systems of the body. Development takes place through the processes of cell division, cell migration, cell differentiation, and cell death, as well as hormonal influences. 3. fetal- 9th week to birth. Continued development of physical structures and rapid growth of the body. Increasing levels of behavior, sensory experience, and learning.
Present and interpret evidence for the "Fetal Experience"- the motor, sensory, and learning abilities of fetuses, and the ways in which the fetus's behavior contributes to its own development, including research methods (habituation and preference methods) used to illustrate these. Be able to apply these research methods to new questions or situations.
motor, sensory, and learning abilities - -sight and touch - , experience tactile stimulation as a result of its own activity. In the course of moving around, its hands come into contact with other parts of its body: fetuses have been observed not only grasping their umbilical cords but also rubbing their face and sucking their thumb. -Taste: A physician named DeSnoo devised an ingenious treatment for women with excessive amounts of amniotic fluid. He injected saccharin into their amniotic fluid, hoping that the fetus would help the mother out by ingesting increased amounts of the sweetened fluid, thereby diminishing the excess. And, in fact, tests of the mothers' urine showed that the fetuses ingested more amniotic fluid when it had been sweetened, demonstrating that taste sensitivity and flavor preferences exist before birth. smell:Smells can be transmitted through liquid, and amniotic fluid comes into contact with the fetus's odor receptors through fetal breathing, providing fetuses with the opportunity for olfactory experience. (from what mothers have eaten, like curry or coffee.) -hearing: research has demonstrated that external sounds that are audible to the fetus include the voices of people talking to the woman. In addition, the prenatal environment includes many maternal sounds—the mother's heartbeat, blood pumping through her vascular system, her breathing, her swallowing, and various rude noises made by her digestive system. learning - Direct evidence for human fetal learning comes from studies of habituation, one of the simplest forms of learning. -Half of the fetuses listened to a recording of their mother reading a poem, played through speakers placed on their mother's abdomen. The other half listened to recordings of the same poem read by another woman. The researchers found that fetal heart rate increased in response to the mother's voice, and decreased in response to the other woman's voice. These findings suggest that the fetuses recognized (and were aroused by) the sound of their own mother's voice relative to a stranger's voice. For this to be the case, fetuses must be learning and remembering the sound of their mother's voice. how does the fetus contribute to its own development? - swallowing amniotic fluid and making breathing motions. -One benefit of this activity is that the tongue movements associated with drinking and swallowing promote the normal development of the palate (Walker & Quarles, 1976). In addition, the passage of amniotic fluid through the digestive system helps it to mature properly. Thus, swallowing amniotic fluid prepares the fetus for survival outside the womb. -breathing: Beginning as early as 10 weeks after conception, the fetus promotes its respiratory readiness by exercising its lungs through "fetal breathing," moving its chest wall in and out what research methods support this? -habituation and preference methods -With the two pads located on either side of their head, the infants revealed a preference for the scent of their own amniotic fluid by keeping their head oriented longer toward that scent -they prefer their mothers voice, the language they heard in the womb. -DeCasper and Spence (1986) asked pregnant women to read aloud twice a day from The Cat in the Hat (or another Dr. Seuss book) during the last 6 weeks of their pregnancy. Thus, the women's fetuses were repeatedly exposed to the same highly rhythmical pattern of speech sounds. The question was whether they would recognize the familiar story after birth. To find out, the researchers tested them as newborns. The infants were fitted with miniature headphones and given a special pacifier to suck on (see Figure 2.15). When the infants sucked in one particular pattern, they heard the familiar story through the headphones, but when they sucked in a different pattern, they heard an unfamiliar story. The babies quickly increased their sucking in the pattern that enabled them to hear the familiar story. Thus, these newborns apparently recognized and preferred the rhythmic patterns from the story they had heard in the womb.
Explain the principle of the "organized newborn," by describing the basic abilities, characteristics, and states of newborn infants, and how they help newborns adapt to their environments.
sleeping- Why do infants spend so much time in REM sleep? Some researchers believe that it helps develop the infant's visual system. -learning: In one study that investigated this possibility, infants were exposed to recordings of Finnish vowel sounds while they slumbered in the newborn nursery. When tested in the morning, their brain activity revealed that they recognized the sounds they had heard while asleep. crying - Infants cry for many reasons—including illness, pain, and hunger—that require the attention of caregivers. Parents are likely to attempt to quiet their crying infant by taking care of the infant's needs, thereby promoting the infant's survival. This fact has led some researchers to suggest that in times of hardship, such as famine, cranky babies are more likely to survive than are placid ones, possibly because their distress elicits adult attention and they consequently get more than their share of scarce food resources
