Prenatal Development PDF

Prenatal Development A HEALTHY START IS CENTRAL TO THE HUMAN LIFE COURSE, WITH BIRTH HOLDING THE HIGHEST RISK OF DEATH, DISABILITY AND LOSS OF DEVELOPMENT POTENTIAL, LEADING TO MAJOR SOCIETAL EFFECTS.” Normal Development “Average or on on-time growth based on the attainment of specific physical, co...

Prenatal Development A HEALTHY START IS CENTRAL TO THE HUMAN LIFE COURSE, WITH BIRTH HOLDING THE HIGHEST RISK OF DEATH, DISABILITY AND LOSS OF DEVELOPMENT POTENTIAL, LEADING TO MAJOR SOCIETAL EFFECTS.” Normal Development “Average or on on-time growth based on the attainment of specific physical, cognitive, linguistic, social-emotional, and behavioral milestones across specific stages” Every area of psychology can be looked at from this perspective biological development, social development, cognitive/perceptual development, personality development. Is IQ inherited or determined early environment? Is there a ‘criminal’ gene? Is sexual orientation a choice or genetically determined? Nature is your genes. The physical and personality traits determined by your genes stay the same irrespective of where you were born and raised. Nurture refers to all the environmental variables that impact who we are, including our early childhood experiences, how we were raised, our social relationships, and our surrounding culture. Heredity, Patterns of Genetic Inheritance Autosomes first 22 pairs of chromosomes 23rd pair of chromosomes; these determine the sex of the child--When the 23rd pair consists of an X and a Y chromosome, the result is a boy; two X chromosomes produce a girl. Each group of compounds that provides a specific set of biochemical instructions is a gene. The complete set of genes makes up a person’s heredity and is known as the person’s genotype. Genetic instructions, in conjunction with environmental influences, produce a phenotype, an individual’s physical, behavioral, and psychological features Conti… Genes are inherited in pairs on the chromosomes, we may receive either the same version of a gene from our mother and father, that is, be homozygous for that characteristic the gene influences. If we receive a different version of the gene from each parent, that is referred to as heterozygous. Dominant-recessive inheritance: a form of genetic inheritance in which phenotype reflects only the dominant alleles of heterogenous pair Some dominant traits include having facial dimples, curly hair, normal vision, and dark hair. Some recessive traits include red hair, being nearsighted, and straight hair. Polygenic, meaning they are the result of several genes—height, intelligence, temperament, certain form of cancer Sometimes the dominant gene does not completely suppress the recessive gene; this is called incomplete dominance. Genetic Disorders Genetics can derail development in two ways: First, some disorders are inherited--Most of the known genetic disorders are dominant gene-linked; however, the vast majority of dominant gene linked disorders are not serious or debilitating. Second, sometimes eggs or sperm do not include the usual 23 chromosomes but have more or fewer chromosomes instead Chromosomal Disorders Sometimes individuals do not receive the normal complement of 46 chromosomes. If they are born with extra, missing, or damaged chromosomes, development is always disturbed. Behavioral Genetics The scientific study of the interplay between the genetic and environmental contributions to behavior. Research has shown how the environment and genotype interact in several ways. Genotype-Environment Correlations refer to the processes by which genetic factors contribute to variations in the environment. Passive genotype-environment correlation occurs when children passively inherit the genes and the environments their family provides. For example, Certain behavioral characteristics, such as being athletically inclined, may run in families. The children have inherited both the genes that would enable success at these activities, and given the environmental encouragement to engage in these actions. Conti… Evocative genotype-environment correlation refers to how the social environment reacts to individuals based on their inherited characteristics. For example, whether one has a more outgoing or shy temperament will affect how he or she is treated by others. Active genotype-environment correlation occurs when individuals seek out environments that support their genetic tendencies. This is also referred to as niche picking. For example, children who are musically inclined seek out music instruction and opportunities that facilitate their natural musical ability. PRE-NATAL DEVELOPMENT As with all life stages, the rate of prenatal development varies slightly from one person to another. The foundation for lifelong development starts at conception. The most rapid period of human physical development occurs in the womb. Factors that contribute to prenatal development: mother’s nutrition, age, mental health, level of exercise, amount of sleep, intake of vitamins and minerals mother’s use of tobacco, alcohol, and other drugs genetic or inherited conditions Stages of Prenatal Development ▪Conception The union of a sperm cell and female egg cell to form a new organism. ▪Germinal happens 2 weeks after fertilization includes, ▪Creation of the zygote, continued cell division, and the attachment of the zygote to the uterine wall. ▪Embryonic happens 2 to 8 weeks after conception, and zygote becomes Embryo, organs appear, the single fertilized cell is now 10,000 times largen than the times of conception ▪Fetal 2-7 months after conception growth and development continue dramatically, through out the pregnancy the genitals can now be identify by male or female. Trimesters 1st Trimester: Weeks 1 – 12 2nd Trimester: Weeks 13 – 27 3rd Trimester: Weeks 28 – 40 Brain Development Prenatal brain development begins in the third gestational week with the differentiation of stem cells, which are capable of producing all the different cells that make up the brain (Stiles & Jernigan, 2010). The location of these stem cells in the embryo is referred to as the neural plate. By the end of the embryonic period, or week eight, the neural tube has further differentiated into the forebrain, midbrain, and hindbrain. during the fetal period involves neuron production, migration, and differentiation. From the early fetal period until midgestation, most of the 85 billion neurons have been generated and many have already migrated to their brain positions. Neurogenesis, or the formation of neurons, is largely completed after five months of gestation. One exception is in the hippocampus, which continues to develop neurons throughout life. Teratogens The study of factors that contribute to birth defects is called teratology. Teratogens are environmental factors that can contribute to birth defects, and include some maternal diseases, pollutants, drugs and alcohol.  Some Teratogens (to a Fetus or Newborn) Drugs: Maternal Diseases ◦ Alcohol ◦ AIDS ◦ Birth Control Pills ◦ Chicken Pox ◦ Caffeine ◦ Chlamydia (STD) ◦ Cytomegalovirus (CMV) ◦ Cocaine ◦ Gonorrhea (bacterial infection) ◦ Heroin ◦ Genital Herpes ◦ Marijuana ◦ Influenza ◦ Methadone ◦ Mumps ◦ Nicotine ◦ Rubella (German Measles) Environmental Pollutants ◦ Syphilis ◦ Lead (chemical element) ◦ Toxoplasmosis ◦ Mercury ◦ PCBs (highly toxic industrial compounds) FACTORS INFLUENCING PRENATAL RISKS The timing of the exposure: Structures in the body are vulnerable to the most severe damage when they are forming. For example, the ears and arms reach their critical periods at about 6 weeks after conception. If a mother exposes the embryo to certain substances during this period, the arms and ears may be malformed. The amount of exposure: Some substances are not harmful unless the amounts reach a certain level. The critical level depends in part on the metabolism of the mother. The number of teratogens: Fetuses exposed to multiple teratogens typically have more problems than those exposed to only one. Genetics: Genetic make-up also plays a role on the impact a particular teratogen might have on the child. The genetic make-up of the mother can also have an effect; some mothers may be more resistant to teratogenic effects than others. Being male or female: Males are more likely to experience damage due to teratogens than are females. It is believed that the Y chromosome, which contains fewer genes than the X, may have an impact. Alcohol Alcohol consumption during pregnancy can lead to fetal death, but also can result in Fetal Alcohol Spectrum Disorders (FASD), umbrella term for the range of effects that can occur due to alcohol consumption during pregnancy. The most severe form of FASD is Fetal Alcohol Syndrome (FAS). Children with FAS share certain physical features such as flattened noses, small eye holes, and small heads. Cognitively, these children have poor judgment, poor impulse control, higher rates of ADHD, learning issues, and lower IQ scores. These developmental problems and delays persist into adulthood (Streissguth, Barr, Kogan, & Bookstein, 1996) and can include criminal behavior, psychiatric problems, and unemployment. Conti… Tobacco: Another widely used teratogen is tobacco as more than 7% of pregnant women smoked in 2016 (Someji & Beltran-Sanchez, 2019). Tobacco use during pregnancy has been associated with low birth weight, preterm delivery, stillbirth, fetal growth restriction, sudden infant death syndrome (SIDS), birth defects, learning disabilities, and early puberty in girls (Center for Disease Control, 2015). A woman being exposed to secondhand smoke during pregnancy has also been linked to low-birth weight infants. Exposure to thirdhand smoke, or toxins from tobacco smoke that linger on clothing, furniture, and in locations where smoking has occurred, results in a negative impact on infants’ lung development. Rehan, Sakurai, and Torday (2011) found that prenatal exposure to thirdhand smoke played a greater role in altered lung functioning in children than exposure postnatally. Conti… Prescription/Over-the-counter Drugs: About 70% of pregnant women take at least one prescription drug (March of Dimes, 2016). For example, the pain reliever ibuprofen can cause serious blood flow problems to the fetus during the last three months. Illicit Drugs: Common illicit drugs include cocaine, ecstasy and other club drugs, heroin, marijuana, and prescription drugs that are abused. The use of cocaine is also connected with low birth weight (in some cases), stillbirths and spontaneous abortion. Heavy marijuana use is associated with problems in brain development (March of Dimes, 2016c). If a baby’s mother used an addictive drug during pregnancy that baby can get addicted to the drug before birth and go through drug withdrawal after birth, also known as Neonatal abstinence syndrome Other complications of illicit drug use include premature birth, smaller than normal head size, birth defects, heart defects, and infections. Babies born to mothers who use drugs may have problems later in life, including learning and behavior difficulties, slower than normal growth, and die from sudden infant death syndrome Conti… Pollutants: There are more than 83,000 chemicals used in the United States with little information on the effects of them during pregnancy, e.g. Lead (An environmental pollutant), Bisphenol, Radiation, Mercury High blood pressure, low birth weight, prematurity, miscarriage, and slowed neurological development, slow the baby’s growth, cause birth defects, affect brain development, cause cancer, and result in a miscarriage, hearing and vision Toxoplasmosis: cause premature birth, stillbirth, and can result in birth defects to the eyes and brain, ten percent may experience eye infections, enlarged liver and spleen, jaundice, and pneumonia. To avoid being infected, women should avoid eating undercooked or raw meat and unwashed fruits and vegetables, touching cooking utensils that touched raw meat or unwashed fruits and vegetables, and touching cat feces, soil or sand. Conti… German measles (or rubella):If the mother contracts the disease during the first three months of pregnancy, damage can occur in the eyes, ears, heart or brain of the unborn child. Deafness is almost certain if the mother has German measles before the 11th week of prenatal development and can also cause brain damage. Maternal Factors Mothers over 35: Most women over 35 who become pregnant are in good health and have healthy pregnancies. However, according to the March of Dimes (2016d), women over age 35 are more likely to have an increased risk of: Fertility problems High blood pressure Diabetes Miscarriages Placenta Previa (baby's placenta partially or totally covers the mother's cervix) Cesarean section Premature birth Stillbirth A baby with a genetic disorder or other birth defects Teenage Pregnancy: A teenage mother is at a greater risk for having pregnancy complications including anemia, and high blood pressure. These risks are even greater for those under age 15. Premature and low birthweight babies may have organs that are not fully developed which can result in breathing problems, bleeding in the brain, vision loss, and serious intestinal problems They may engage in negative behaviors including eating unhealthy food, smoking, drinking alcohol, and taking drugs. Additional concerns for teenagers are repeat births Gestational Diabetes: cause premature birth, stillbirth, the baby having breathing problems at birth, jaundice, or low blood sugar. High Blood Pressure (Hypertension):High blood pressure during pregnancy can cause premature birth and low birth weight (under five and a half pounds), placental abruption, and mothers can develop preeclampsia (high blood pressure and signs that the liver and kidneys may not be working properly). Rh Disease: Rh is a protein found in the blood--at risk of having a baby with a form of anemia called Rh disease--jaundice, anemia, heart failure, brain damage and death. Weight Gain during Pregnancy: Women who gain too little may have a baby who is low-birth weight, while those who gain too much are likely to have a premature or large baby. Stress: Feeling stressed is common during pregnancy, but high levels of stress can cause complications including having a premature baby or a low-birthweight baby, baby’s brain development and immune system functioning, as well as childhood problems such as trouble paying attention and being afraid Depression: Consequences of depression include the baby being born premature, having a low birthweight, being more irritable, less active, less attentive, and having fewer facial expressions. Paternal Impact: offspring of men over 40 face an increased risk of miscarriages, autism, birth defects, bone growth disorder and schizophrenia. Thank you