Prenatal Development And Birth PDF

CHAPTER FIVE: PRENATAL DEVELOPMENT AND BIRTH After completing Chapter Five students will be able to: Discuss the evolutionary perspective on development Describe how genes impact human development Describe important reproductive challenges and choices Character...

CHAPTER FIVE: PRENATAL DEVELOPMENT AND BIRTH After completing Chapter Five students will be able to: Discuss the evolutionary perspective on development Describe how genes impact human development Describe important reproductive challenges and choices Characterize how heredity and environment interact to produce individual changes in development Describe the three periods of prenatal development Describe potential hazards during prenatal development Discuss the stages, transitions and decisions involved in birth Characterize the development of low-birth-weight infants Describe three measures of neonatal health and responsiveness Explain the physical and psychological aspects of the postpartum period Chapter Five: Prenatal Development and Birth | 91 92 | Chapter Five: Prenatal Development and Birth The Role of Genetics Jim Springer and Jim Lewis were identical twins separated at 4 weeks of age. CBS NEWS: Twin brothers separated at birth reveal striking genetic similarities When they were reunited at the age of 39, they discovered that they possessed striking similarities. Both worked as deputy sheriffs, suffered from tension headaches, vacationed in Florida, were prone to nail biting, smoked Salem cigarettes, drove Chevrolets, had dogs named Toy and married and divorced women named Betty. One twin named his son James Allan, and the other named his son James Alan. Both preferred math over spelling and enjoyed carpentry and mechanical drawing. The study of the “Jim twins” brings up the debate of nature vs. nurture and which has a greater impact on a child’s Image: Ripley’s Believe It or Not! development-their environment or their genetics. Jim Springer and Jim Lewis were part of a landmark study, The Minnesota Twin Family Study, conducted from 1979 to 1999, which followed identical and fraternal twins who were separated at an early age. Researchers at the University of Minnesota, led by Thomas Bouchard, launched the landmark study. Over the course of 20 years, they studied 137 pairs of twins: 81 pairs of identical twins (twins who developed from one egg that split in two), and 56 pairs of fraternal twins (twins who developed from two eggs fertilized by two different sperm). The study set out to determine the impact of nature (genes) vs. nurture (environment) on a child’s development. This topic has also come up in a 2018 film entitled “Three Identical Strangers.” The film follows triplets separated at birth and grapples with the question of whether nature or nurture had a greater impact on their long-term development. In this case, the triplets born in 1961 were studied extensively, not knowing that they had each other until adulthood. The case is tragic in many ways. Many siblings separated by the Louise Wise Adoption Services have since found each other. The intricacies of the research that was done remains in closed files (Wardle et al; 2018). When genetically identical twins separated as infants show such striking similarities, can we conclude that their genes caused these similarities? The Minnesota study of identical twins points to both the importance of the genetic basis of human development and the need for further research on genetic and environmental factors (Bouchard, Lykken et. al. 1990). Certainly, genes play a crucial role in the way a child develops. In this chapter, we will discuss the impact genes have on a child’s development. Natural selection is the evolutionary process that favors individuals best adapted to survive and reproduce. Evolutionary psychology emphasizes adaptation, reproduction, and “survival of the fittest” in shaping behavior. Just as evolution shapes our physical features, it also influences how we make decisions, how aggressive we are, and our mating patterns. For example, if our ancestors were hunters and gatherers and the men did most of the hunting and the women gathered seeds and plants for food, the men would have to possess certain physical traits to travel long distances and hunt and kill animals. Those born with these traits would be more likely to gather more food, attract stronger mates and reproduce. Evolutionary developmental psychologists believe in the importance of childhood. They believe that an extended “juvenile” period for learning information is crucial. What is learned in childhood prepares children for adulthood. It is important to understand how conception takes place to better understand genetic and chromosomal abnormalities that might impact a child’s development. Reproduction occurs when the female gamete (ovum) is fertilized by the male gamete (sperm). They join to form the first cell of life (the zygote). This cell contains 23 pairs of chromosomes. The Role of Genetics | 93  The zygote is the first cell of human life. Life begins as a single cell with a nucleus. Each nucleus has 23 pairs of chromosomes, one member of each pair coming from each parent. DNA is a complex molecule that contains genetic information. Genes are the units of hereditary information composed of DNA. Cells divide in two different ways. Mitosis is cellular reproduction in which the cell’s nucleus duplicates itself with two new cells being formed. Each new cell contains the same DNA as the parent cell, with the same 23 pairs of chromosomes. Meiosis is a specialized form of cell division that occurs to form eggs and sperm (or gametes) (Santrock, 2013), Genotype is the actual genetic material. Phenotype is the way an individual’s genotype is expressed in measurable or observable characteristics (Berk, 2017). Males have X and Y chromosomes. Females have two X chromosomes. In some cases, one gene of a pair always exerts its effects; it is dominant, overriding the potential influence of the other gene, called the recessive gene. A recessive gene exerts its influence only if the two genes of a pair are both recessive. If you inherit a recessive gene from both of your parents, you will inherit that recessive gene. If you inherit a recessive gene from just one of your parents, you may never know you carry the gene. Brown hair, farsightedness, and dimples rule over blond hair, nearsightedness, and freckles in the world of dominant-recessive genes. However, most characteristics are not caused by only one gene. Most are determined by the interaction of several genes. This is called polygenic inheritance. This is a picture of the dominant-recessive genes principle. 94 | The Role of Genetics  If a parent passes along a dominant gene for brown hair, their child will be born with brown hair. The only way they will have a blond-haired child is if both parents pass on a recessive gene for blond hair. Page URLs: https://www.cbsnews.com/news/twin-brothers-separated-at-birth-reveal-striking-genetic-similarities/ https://www.businessinsider.com/three-identical-strangers-twin-studies-nature-vs-nurture-2018-7 Media Attributions Jim and Jim twins © Ripley's Believe It or Not! is licensed under a All Rights Reserved license Autosomal Dominant and Recessive © Wikimedia is licensed under a CC BY-SA (Attribution ShareAlike) license The Role of Genetics | 95 Concerns in Conception Once you have a basic understanding of what a typical cell includes (23 pairs of chromosomes), it is easier to understand how chromosomal abnormalities occur. A chromosomal abnormality occurs when a gamete does not have a normal set of 23 chromosomes. Down Syndrome is the most common chromosomal abnormality. It occurs when an extra chromosome causes mild to severe cognitive and physical delays. Advanced maternal age appears to have an impact on the likelihood of a woman giving birth to a child with Down Syndrome. If a mother is age 20, this syndrome occurs in 1 in 1,900 births. If a mother is 35, it occurs in 1 out of 300 births. If a mother is age 45, it occurs in 1 out of 30 births (National Institute of Health, 2018). Down Syndrome is interesting when considering the nature vs. nurture debate. Although the condition cannot be reversed, early intervention can lead to much more positive outcomes. Children with Down Syndrome can grow up to be adults who live independent, healthy, productive lives. Some other common chromosomal conditions that may be encountered when working with young children: Klinefelter Syndrome occurs when an extra X chromosome causes physical abnormalities. It occurs in one out of six hundred male births. Hormone therapy can be effective. Fragile X Syndrome is an abnormality in the X chromosome that can cause cognitive delays, learning disabilities and a short attention span. It is more common in males than females. Turner Syndrome, which occurs in one out of two thousand five hundred live births, develops when a female is missing an X chromosome. It causes cognitive delays and sexual underdevelopment. Hormone therapy in childhood and puberty can be beneficial. XYY Syndrome occurs when an extra Y chromosome is present. It can cause above average height (Santrock, 2013). Gene-Linked Abnormalities Gene-linked abnormalities can be caused by harmful genes. Here are some examples of gene-linked abnormalities: Phenylketonuria, or PKU occurs when an individual cannot properly metabolize an amino acid; a special diet can result in average intelligence and a normal life span. If left untreated, it causes mental retardation. This is an excellent example of how nurture (the environment) can positively impact nature (the results of genetic inheritance). If this condition is treated, a child goes on to live a perfectly normal, healthy life. Sickle-cell anemia occurs mainly in the African American population. It is caused by a recessive gene. It is a blood disorder that limits the body’s oxygen supply. It can cause heart and kidney failure, as well as joint swelling. There is no cure for sickle cell anemia. Prenatal Testing for Genetic Abnormalities There are several tests that can be performed prenatally to give women information about how the fetus is developing. An ultrasound is the most common prenatal test. High frequency sound waves are directed into the pregnant woman’s abdomen. The echo from the sounds creates a picture. Ultrasounds can detect many abnormalities in the fetus, including microencephaly, a condition caused by an abnormally small brain. Ultrasounds can also determine the number of fetuses and give clues to the baby’s sex. The ultrasound 96 | Concerns in Conception procedure is non-invasive, meaning it is done outside the body. There is no risk to the mother or the fetus when this test is administered (Berk, 2017). Between the 10th and 12th weeks of pregnancy, chorionic villi sampling may be performed. In this procedure, a sample of the placenta is taken to test for chromosomal or genetic abnormalities. There is a small risk of limb deformity, and this test can cause false positives if a woman does not know the exact date of conception. Amniocentesis is another test that is administered to many women during pregnancy. During an amniocentesis, a sample of amniotic fluid is taken to test for chromosomal and metabolic disorders. This is an invasive procedure because the medical professional is going into the amniotic sac to take a sample of fluid. Amniocentesis provides a small risk of miscarriage but provides a great deal of accurate information regarding chromosomal and genetic conditions (Berk, 2017; Santrock, 2013). Maternal blood screening (sometimes called the AFP test) identifies pregnancies that have an elevated risk for birth defects such as spina bifida. Triple screen measures three substances in the mother’s blood. It is noninvasive because the doctor is not going into the amniotic sac. After an abnormal triple screen, the next step is usually an ultrasound. If an ultrasound does not explain the abnormal triple screen, amniocentesis is typically used. All these prenatal tests give women important information about their developing fetus (Berk, 2017). Other Concerns For some women, conceiving a child can be extremely difficult. Infertility is an inability to conceive after 12 months of regular intercourse (Santrock, 2013). As women have chosen to have children later in life, the rates of infertility have risen, due in some part to advanced maternal age. There are several strategies to deal with infertility: in vitro fertilization (IVF), gamete intrafallopian transfer (GITF) and zygote intrafallopian transfer (ZIFT). IVF has a 31% success rate. GITF has a 24.5% success rate and ZIFT has a 29.2% success rate (Zarinara, 2021). People who continue to struggle with infertility often consider adoption. Concerns in Conception | 97 The Germinal Period Now that we understand the process of conception, let’s explore what happens once the egg is fertilized and the zygote is created. The Germinal Period is the first two weeks after conception. The zygote is created and cells continue to divide. At approximately 10 days after conception, the zygote attaches to the uterine wall. This is called implantation. Even at this early date, the differentiation of cells has begun. The blastocyst (blastocoel) is an inner layer of cells that later develops into the embryo. The trophoblast is the outer layer of cells that provides nutrition and support for the embryo. The embryonic period occurs two to eight weeks after conception. Organogenesis, or organ formation, begins and the support systems for cells form. The embryo has three layers of cells. The endoderm is the inner layer of cells which becomes the digestive and respiratory systems. The ectoderm is the outer layer of cells which forms the nervous system, sensory receptors and skin. The mesoderm is the middle layer of cells which forms the circulatory, excretory and reproductive systems as well as bones and muscles. The embryo has a complex life support system. The placenta provides nutrition for the embryo. The umbilical cord connects the baby to the placenta. The amnion, or amniotic sac, is an envelope in which the baby floats. It is temperature controlled, humidity controlled and virtually shock proof (Santrock, 2013). 98 | The Germinal Period  The fetal period occurs two months after conception and lasts for approximately seven months until the baby is born. The largest prenatal weight gains occur during this period. Fingers, toes, skin, lungs and reflexes all develop as the baby prepares for birth. The three trimesters are different from the three prenatal periods. In fact, the embryonic period, the germinal period and the beginning of the fetal period all occur during the first trimester! The Germinal Period | 99 Media Attributions The Germinal Period © OpenStax College via. Wikimedia Commons is licensed under a CC BY-SA (Attribution ShareAlike) license Pregnancy side diagram © Bruce Blaus via. Wikimedia Commons is licensed under a CC BY-SA (Attribution ShareAlike) license Three Trimesters of Fetal Development © Mhuerth01 via. Wikimedia Commons is licensed under a CC BY- SA (Attribution ShareAlike) license 100 | The Germinal Period Pregnancy Concerns How long does a typical pregnancy last? People generally answer nine months, but that is not exactly true. Fetal life begins with ovum fertilization. Pregnancy is calculated from the first day of the woman’s last menstrual period and generally lasts about 40 weeks, which is closer to ten months! Some early signs and symptoms of pregnancy are missed menstrual period, breast changes, aching in lower abdomen, fatigue, nausea and frequent urination. During the first trimester women feel extreme fatigue, nausea and emotional changes. During the second trimester they begin to feel less nauseous, and the uterus expands into the abdominal cavity. During the third trimester, women anticipate the end of pregnancy and the uterus expands to the point below the breastbone. From the first sign of pregnancy a woman needs to be careful about what she eats, drinks, and how she takes care of her body. Many factors can have an impact on the health and well-being of the embryo/fetus. Risk Factors Teratogen A teratogen is anything that causes a birth defect. The severity of the defect is determined by the dose, whether a child is genetically susceptible, and when they were exposed to the teratogen. Antibiotics, some antidepressants, certain hormones, diet pills, aspirin and too much caffeine can all affect the fetus. Pregnancy Concerns | 101  Psychoactive drugs act on the nervous system. They change moods and modify perceptions. Alcohol can be extremely dangerous if it is abused when a woman is pregnant. Fetal Alcohol Syndrome (FAS) causes cognitive and physical delays which can be extremely severe. FAS refers to a range of disorders caused by drinking alcohol during pregnancy. Fetal alcohol syndrome can cause abnormal facial features, growth deficiency, and problems with the central nervous system. Children with fetal alcohol syndrome may also have learning disabilities, attention span disorders, and other physical disabilities, including vision and hearing problems. The only way to prevent Fetal Alcohol Syndrome is to refrain from drinking during pregnancy. Smoking during pregnancy can lead to low birth-weight infants who often struggle with lung development. Cocaine, marijuana, methamphetamine and heroin are all teratogens that pose a great risk to the fetus. Cocaine: Babies born to women who used cocaine often have smaller heads and a lower IQ. They struggle with cognitive performance, information processing, and attention to tasks. Marijuana: Babies born to mothers who smoke marijuana have a lower birth weight and underdeveloped lungs. Methamphetamine: Women who use methamphetamines are more likely to miscarry or give birth to low birth-weight infants. Infants experience irritability, feeding issues and failure to thrive. Heroin: Babies born to women who used heroin often experience serious withdrawal symptoms and are extremely irritable. Long term they can experience cognitive delays and attention issues. Environmental Hazards Environmental hazards also pose a great risk to the fetus. Fathers’ exposure to lead and radiation, certain pesticides, petrochemicals, toxic waste, and manufactured chemicals are all cause for concern. Medical Conditions There are also many medical conditions that can pose a risk to the fetus. (CDC) Rubella is very dangerous for a woman and her developing baby. Most Americans are now vaccinated against rubella (MMR vaccine) but if a woman contracts rubella during pregnancy, it can have an extremely negative impact on her infant including: Deafness Heart Defect Cataracts Intellectual Disabilities Liver and Spleen Damage Low Birth-weight Skin Rash Syphilis is a sexually transmitted disease. It is especially important that women share their sexual history with their OB/GYN to help protect their unborn baby. If a woman has syphilis, she can give birth to a baby that has cognitive delays. Genital Herpes is also a sexually transmitted disease. If a baby is born vaginally, the baby can be born blind or can tragically die during the birth process. If a baby is born by c-section, they will be absolutely fine. AIDS is a sexually transmitted disease that can be passed from mother to child through blood, breast milk 102 | Pregnancy Concerns and the birth canal. If a mother is being treated for AIDS, chooses to deliver by c- section and bottle feeds, the child’s likelihood of contracting AIDS decreases dramatically (Santrock, 2013). Other Concerns Other parental factors that can affect a fetus are obesity, maternal nutrition, maternal age, paternal age, emotional states and stress and maternal hormone treatments. On average, a woman gains 25 to 35 pounds during pregnancy. Pregnant women need to drink lots of water and increase protein, iron, vitamin D, calcium, phosphorous and magnesium. Women should be careful about how much weight they gain. Maternal obesity can increase hypertension, diabetes, respiratory complications and infections. It is fine to exercise during pregnancy. Women should exercise for shorter intervals and decrease intensity as pregnancy progresses. Avoiding teratogens, eating healthy food, decreasing stress and participating in a frequent, low impact exercise routine can help ensure a healthy baby and an easier birth process. One or more interactive elements has been excluded from this version of the text. You can view them online here: https://rotel.pressbooks.pub/whole-child/?p=778#oembed-1 Media Attributions Teratogens chart © Martha Lally and Suzanne Valentine-French. Provided by: College of Lake County Foundation is licensed under a CC BY-SA (Attribution ShareAlike) license Pregnancy Concerns | 103 Birth The experience of birth is a life changing event, especially for parents who are experiencing it for the first time. As a woman prepares for the baby’s birth, Braxton Hicks contractions increase, the cervix becomes thinner, and there is a strong desire for the pregnancy to end. Braxton Hicks contractions are a tightening in the abdomen that comes and goes. They are contractions of your uterus in preparation for giving birth. They tone the muscles in your uterus and may also help prepare the cervix for birth. Women may also begin nesting and experience bursts of energy as their due date approaches. There are three stages of birth. The first lasts about 12 to 24 hours. Contractions begin about 15-20 minutes apart. They occur closer together as birth nears. The cervix dilates to about 4 inches. This allows the baby to move from the uterus to the birth canal. The second stage lasts approximately 45 minutes to an hour. The baby moves through the cervix and the birth canal. Contractions come almost every minute. The baby is born! The third stage lasts only minutes. The placenta, umbilical cord, and other membranes are detached and expelled. Women can use medicine, birthing strategies, and people to help provide support during the birthing process. Doulas are professionals trained in childbirth who assist a woman before, during, and after her pregnancy. Mothers experience less pain, anxiety, and depression when provided with this support. Midwives are medically trained professionals who assist the mother prenatally and throughout the entire birthing process. As midwives have gained popularity, many women choose to deliver in a birthing center with a midwife attending rather than in a sterile hospital room under a doctor’s care. There are three types of medications commonly used during the birthing process. Analgesics alleviate pain. Anesthesia blocks pain. Oxytocics are synthetic hormones used to stimulate contractions and speed up labor. Natural childbirth tends to reduce a mother’s pain by decreasing her fear. Prepared childbirth is like natural childbirth, but a special breathing technique is used in the final stage of labor. The Lamaze method is the most well-known method. Women are educated to understand what is happening with their bodies and to use breathing/relaxation techniques to help manage the pain. Nearly one in four U.S. births are c-sections. The baby is removed from the uterus through an incision in the abdomen. C-sections are procedures that are performed when the baby is breech (feet first), the head is too large, vaginal bleeding has occurred, the baby is in distress, the mother is in distress, the mother has an STD, the mother has had a prior c section, or in the case of multiple births. In today’s world, many fathers are trained to coach the mother during labor and siblings are given information prior to the birth to help address the child’s emotions and behaviors in an age-appropriate way. The most common method that places the father in the role of labor coach is the Bradley Method (Berk, 2017; Crain, 2011). 104 | Birth After Birth A low birth weight infant weighs less than 5.5 pounds. An extremely low birth weight infant weighs less than 2 pounds. A preterm baby is born at least three weeks early. Both preterm and low birth weight infants struggle with lung development. Low-birth weight infants have more health and developmental problems and are more likely to have a learning disability, ADD or ADD and breathing problems. It is important to nurture preterm infants carefully. Massage has led to greater weight gain, improved skills, and better academic performance. Kangaroo care is extremely important for preterm infants. This skin-to-skin contact leads to better sleeping, more weight gain, less crying and longer periods of alertness. The Apgar Scale is widely used to assess health at 1 and 5 minutes after birth. This is usually administered by the nurse and is one way to identify high-risk infants. The Apgar Scale tests skin color, pulse rate, reflexes, activity, and respiratory effort. The Brazelton Neonatal Behavioral Assessment Scale is performed within 24 to 36 hours after birth. It tests neurological development, reflexes and reactions to people. The Postpartum Period lasts approximately six weeks. It is the period after childbirth when the mother is adjusting physically and psychologically. Involution is the time when the uterus returns to pre-pregnancy size. During the postpartum period, women experience emotional and psychological changes including anxiety, depression and coping difficulties. Postpartum depression is characterized by strong feelings of sadness, anxiety or despair in new mothers including depression, changes in appetite, crying spells and an inability to sleep. After giving birth, a mother has a difficult decision to make–whether to stay at home or go back to work. Societal, career and financial pressures affect mothers’ options. Fathers can have difficult adjustments as well. The father may feel the baby always comes first in the mother’s mind. However, the postpartum reaction is improved if the father attended childbirth classes and was active in the delivery. It is important that both parents are committed to caring for the newborn. Both parents need to be aware of the young infant’s developmental needs, including physical, psychological and emotional needs. This helps them to bond with their child. Bonding is a close physical bond between the infant and caregiver. Rooming in is one way to create a closer bond. Rooming in is the alternative parents take to have the newborn stay in the hospital room with them rather than the nursery to encourage closer bonding (Crain, 2011; Santrock, 2013). Cross Cultural Childbirth Practices Around the World The following are cross-cultural childbirth practices around the world. As you read about these practices, please consider the following questions: Were you familiar with any of the following birth practices? How do they differ from typical birth practices in the United States? Which did you find most interesting and why? Would you consider giving birth in the United States a natural occurrence or a medical occurrence? After Birth | 105  West Africa: Women are expected to give birth without making any sounds; girls who cry out are called cowards and are expected to have longer labor. Latin American peasants: Massaging to direct the baby down and using long pieces of cloth bound across the upper abdomen are used in the belief that babies might otherwise travel upward instead of descending into the vagina. East Africa: Women experiencing long labor have their vaginas packed with cow dung to encourage the baby to want to be born (i.e., the baby will believe it is being born into a wealthy family). Cuna Indians of Panama: The shaman sings the baby out of the woman’s body. Zuñi Indians: Birth takes place on a hot sand bed 20 inches across and 5 inches high covered by a sheepskin. The sand bed is symbolic of Mother Earth. The Zia of New Mexico: The father dips eagle feathers in ashes and throws the ashes in the four directions. Then he draws the ashy feather down the pregnant woman’s sides and center of the body while praying. The father’s sister places an ear of corn near the pregnant woman’s head and blows on it during the next contraction to aid the father’s prayer. India: A budded flower is placed near the pregnant woman, and her cervix is encouraged to dilate as the flower’s petals open. Manus of New Guinea: The parents confess any hidden anger toward each other so that the childbirth process can go ahead normally. A hot coconut soup is used to comfort the mother. Dominican Republic: Parents put a small bracelet of beads on the child’s ankle or wrist to ward off evil and to bring prosperity. Puerto Rico: Puerto Ricans give their new babies a mano negra de azabache, like the tradition in Israel. It looks like a red-knotted bracelet to wear and ward off evil spirits. (Gross-Loh, 2017; Montgomery, 2013). 106 | After Birth