Toxoplasmosis
Toxoplasmosis is a parasitic infection that, when contracted by a pregnant woman, can pose a serious risk to her unborn baby. Up to one in 1,000 babies in this country are born infected with toxoplasmosis. A pregnant woman who contracts toxoplasmosis for the first time during pregnancy has about a 40% chance of passing the infection on to her fetus. Babies whose mothers had toxoplasmosis in the first trimester usually have the most severe infections. Up to 90% of infected babies appear normal at birth. Yet, 80 to 90% will develop sight-threatening eye infections months to years after birth. Some will also develop hearing loss, hydrocephalus, mental retardation, learning disabilities or seizures. Toxoplasmosis during pregnancy also can result in miscarriage or stillbirth. About one in 10 infected babies has a severe Toxoplasma infection that is evident at birth. These newborns have severe eye infections and other complications. Toxoplasmosis is caused by a parasite. It is most often picked up through exposure to cat feces or by eating raw or undercooked meat that is contaminated with the parasite. Other sources of infection may include raw goat’s milk, raw eggs, and insects such as flies and cockroaches that may have been in contact with cat feces. Toxoplasmosis is one of the most common infections in the world. Most cases go undiagnosed. Symptoms tend to resemble the flu. About 60 to 85% of American women of childbearing age have never had toxoplasmosis and are susceptible to it during pregnancy. If it is suspected that a pregnant woman has an active case, a blood test that detects antibodies can be done. If the woman has an active infection, the fetus is tested also. Studies show that prenatal tests including amniocentesis and ultrasound can usually tell if the fetus is infected. Infected babies should be treated as soon as possible after birth with drugs which can help prevent or reduce the disabilities associated with toxoplasmosis.
Alcohol
Each year approximately 5,000 babies , one in every 750, are born with fetal alcohol syndrome (FAS), a combination of physical and mental birth defects. In addition, almost 50,000 babies are born each year with fetal alcohol effects (FAE), a condition characterized by some, but not all, of the birth defects associated with FAS. Among the known causes of mental retardation, FAS is one of the most common and is the only cause that is entirely preventable. Babies with FAS are abnormally small at birth and usually do not catch up as they get older. Most of them have small eyes, a short upturned nose and small, flat cheeks. Their organs, especially the heart, may not form properly. Most babies
with FAS also have a small brain and some degree of mental retardation. Many have poor coordination, a short attention span, and exhibit behavioral problems. The effects of FAS last a lifetime. No level of drinking has been proven safe. Even moderate amounts of alcohol may damage the fetus. The fetal brain and other organs begin developing around the third week of pregnancy and are vulnerable to damage in those early weeks. Because no amount of alcohol is proven safe, women should stop drinking immediately if they suspect that they might be pregnant. This refers to all types of alcohol, including wine, wine coolers, beer and mixed drinks. Consuming alcohol during pregnancy increases the risk of miscarriage, stillbirth, and death in early infancy. Because there currently is no way to predict which babies will be damaged by alcohol, the safest course is to not drink during pregnancy.
Smoking
Smoking during pregnancy is associated with low birth weight, high rates of SIDS (sudden infant death syndrome), behavior problems, and learning difficulties. It is believed that smoking reduces the flow of oxygen and nutrients to the fetus. There is an increased risk of miscarriages and stillbirths in women who smoke while pregnant. Babies and children who are around smokers have more colds, ear infections, and flu. Children whose parents smoke are more likely to grow up to be smokers.
Cocaine T
his is among the most dangerous drugs to unborn babies. It is estimated that more than 100,000 cocaine-exposed babies are born each year in the United States and that there may be as many as four million cocaine-exposed children by the year 2000. Cocaine use during early pregnancy can cause miscarriage. When the drug is used late in pregnancy, it may trigger labor. It can also cause a stroke or death to the unborn baby. Studies show that women who use cocaine during pregnancy are three times more likely to have a premature baby. Cocaine cuts the flow of nutrients and oxygen to the baby. Cocaine-exposed babies tend to have smaller heads, which may indicate a smaller brain. Cocaine use can also cause the placenta to pull away from the wall of the uterus before labor begins. This condition can be fatal for both mother and baby. Many exposed babies are born too soon or too small. Some studies suggest that cocaine-exposed babies are at increased risk of birth defects. It has been reported that mothers who used cocaine early in pregnancy were five times as likely to have a baby with a malformation of the urinary tract. Babies whose mothers used cocaine during pregnancy often score poorly on tests given at birth. Babies exposed to cocaine before birth also may have respiratory and neurological problems, including seizures,during the newborn period. Beginning at birth, these babies go through withdrawal from the drug. Many are very jittery and irritable. Bonding between mother and baby is often difficult. Babies born to mothers who use drugs during pregnancy are at increased risk for child abuse and neglect.
Rubella
This is a mild, infectious disease caused by a virus. The problem with rubella is the damage it can cause an unborn baby whose mother has it during pregnancy. The first three months are the most dangerous, but the fetus can still be affected by rubella after that time. The earlier in pregnancy that the mother has rubella, the more serious the birth defects usually are. Some of these babies die before or shortly after birth. More common are the lifetime defects that a baby may be left with. Among these are hearing loss or deafness, eye defects, heart defects, mental retardation, and behavior problems. There is a blood test to find out if a person has rubella or has had it at some time. If the test shows rubella antibodies are present, then the person has had the disease and can’t get it again. This test is important for females of childbearing age. There is a vaccination against rubella which makes people immune to the disease. Rubella vaccine is recommended for all children, most teenagers, and many adults. Vaccinating girls as soon as they reach childbearing age protects their future babies. Women of childbearing age should be vaccinated only if they are sure they are not pregnant and don’t expect to be for the next three months.
STD
Sexually transmitted diseases are infections which are caused by engaging in sex with someone who has one of the diseases. It is estimated that 12,000,000 people contract STDs each year. The deadliest STD is AIDS. Other common STDs are syphilis, gonorrhea, chlamydia, genital herpes, and genital warts. All STDs pose a risk to a pregnant woman and her unborn child. If the woman is infected with AIDS the fetus can contract the virus from the mother during pregnancy or delivery. A baby can catch chlamydia during a vaginal birth, causing ear and eye infections, and possible pneumonia. Genital herpes in newborns can cause severe skin infections, nervous system damage, blindness mental retardation or death. Gonorrhea in a baby can cause serious eye infections and blindness. Syphilis can be passed on to the fetus, causing damage to the heart, blood vessels and nervous system, blindness, and death. Genital warts may be contracted by a baby during birth, causing wart growth inside the voicebox and blocking the windpipe.
Stress
Stress can result from the physical and emotional changes of pregnancy. It causes changes in the body, including increased muscle tension, faster breathing, quicker heartbeat and increased blood pressure. How a pregnant woman deals with stress can make a difference in her physical and emotional well-being. It may even affect her unborn baby. Shifts in hormone levels also influence a woman’s psychological state. There is evidence that high levels of stress can adversely affect pregnancy. Some studies suggest a possible relationship between stress and premature labor and low birthweight. Stress also appears to play a role in pregnancies complicated by high blood pressure or diabetes, conditions that also increase the risk of premature labor. Women with a combination of high stress levels and medical risk factors have a risk of premature labor. Not all studies have found a link between stress and low birthweight. Factors that affect an individual’s ability to handle stress include personality, physical and mental health, living conditions, economic status, maturity and support. Stress management techniques such as meditation and other self-awareness programs can help alleviate stress. Walking and a regular exercise program are good options . One of the best ways to help prevent stress is to obtain early, comprehensive and continuous prenatal care.
Low Birthweight
Low birthweight affects one in every 15 babies born each year in the United States. It is related to approximately 60% of infant deaths. These babies may face serious health problems, and are at increased risk of long term disabilities. Low birthweight is a weight of 5 pounds, 8 ounces or less at birth. Very low birthweight is a weight of 3 pounds, 5 ounces or less. Preterm births occur before the 38th week of pregnancy. Most low-birthweight babies are preterm. Small-for-date babies may be full-term but are underweight. The mother’s medical problems influence birthweight, especially if she has high blood pressure, diabetes, certain infections or heart, kidney or lung problems. Smokers have smaller babies than nonsmokers. Drug and alcohol use limits fetal growth. Women under 17 years old or over 35 are at increased risk of having low- birthweight babies. A premature baby may have breathing problems. Up to 75% of babies born before the 30th week suffer from respiratory distress syndrome, a leading cause of death and disability among premature babies. Some low-birthweight babies have salt or water imbalances or low blood sugar which can cause brain damage. A premature baby may be anemic. Infants born too soon may not have had enough time to store iron. Low-birthweight babies may not have enough fat to maintain a healthy body temperature. Bleeding in the brain, which can be one of the most severe results of low birthweights, happens in 40 to 45% of very low-birthweight infants. The bleeding may result in brain damage or death. Premature babies often have a potentially dangerous heart problem. Lifesaving equipment in intensive care nurseries helps sustain low-birthweight babies who otherwise might not survive. The most important prevention is early and regular prenatal care. Women who receive this care can learn good health habits and ways to reduce the risk of having a low-birthweight baby.
Diabetes
This is a disorder in which the body does not produce enough insulin or does not utilize insulin properly. Without treatment, high levels of sugar can accumulate in the blood and damage organs, including blood vessels, eyes, and kidneys. About one in 1,000 pregnant women has had diabetes before pregnancy. Another 3 to 12% develop diabetes for the first time during pregnancy. This is called gestational diabetes and is one of the most common complications of pregnancy. Babies of all diabetic women are at increased risk of health problems arising during the newborn period, including respiratory distress, low blood sugar and calcium levels, and jaundice. Early and regular prenatal care can reduce these risks. The American Diabetes Association recommends that all pregnant woman be screened for gestational diabetes. The screening test is usually done between the 24th and 28th week of pregnancy. All pregnant women with diabetes should follow a special diet and exercise, according to their doctor’s recommendations.
Chicken Pox and Fifth Disease
These diseases can sometimes pose a risk to the fetus if the mother contracts them during pregnancy. If she has been exposed to either of these illnesses, it is important that she inform her doctor. A blood test can usually determine if a person is susceptible to chicken pox. Although most women are immune because they have had the disease, one to five women in 10,000 will come down with chicken pox during pregnancy. This may cause a pattern of birth defects in the fetus in a small number of cases. Chicken pox also may increase the risk of miscarriage and premature labor. When maternal infection occurs around the time of birth, infection in the newborn can often be prevented or lessened if the baby is treated promptly with special medication. Fifth disease in pregnancy has not been proven to cause birth defects. It can, however, disrupt the fetus’s ability to produce red blood cells. Sometimes this leads to a dangerous form of anemia, heart failure, abnormal pooling of fluid, and fetal death. Fewer than one-third of infected mothers pass this infection on to their babies. There is no vaccine to prevent fifth disease or to cure it. A pregnant woman who has been exposed to fifth disease should consult her doctor promptly.
Teaching The Unit
Goal
Students will demonstrate academic progress and developmental growth in scientific knowledge.
Objectives
Students will expand their knowledge in the specific areas of:
1. Genetics
2. Birth disorders
3. Pregnancy
Methodology
Students will gain an understanding of the unit topics in a variety of ways, according to their individual learning styles and ability levels. Materials will be presented in the following manner:
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1. Individual student reading of written, factual information relating to the unit
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2. Group reading of information on topics of specific interest to the group
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3. Teacher lecture and demonstration to inform and clarify unit topics
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4. Whole class, and small group discussions of particular portions of the unit
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5. Experiential, hands-on projects, such as building a cell model, involving all class members, either individually or in small groups
Evaluation
Knowledge and understanding, of the topic units, gained by the students will be evaluated by using the following criteria:
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1. Teacher corrected worksheets
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2. Graded tests
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3. Completed assignments
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4. Teacher observation of group project participation, interaction and results
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5. Teacher observation of individual involvement and contribution to group discussions
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6. Teacher observation of student interest and effort maintained in completing individual projects
Sample Activity
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Unit Topic, Genetics
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This worksheet to be used following study of the unit topic:
Background/Mendel.
Directions
: Choose the best answer from the box. Write that answer in the blank.
recessive
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pea plants
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Gregor
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Mendeltall
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two
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female
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male
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genes
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1. _____ is often called the father of genetics.
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2. He worked in a garden and experimented with _____ .
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3. He observed that the _____ gene is dominant in pea plants and the short gene is _____ .
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4. Today Mendel’s factors are called _____ .
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5. One gene comes from the _____ reproductive cell and the second one comes from the _____ cell.
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6. Organisms receive _____ genes for each trait.
Sample Project
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Unit Topic, Genetics
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To be completed following study of the unit topics:
Cells, Chromosomes, Genes, and DNA.
Directions
: Students will construct individual cell models in the following manner:
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1. Air filled balloons, of various shapes and sizes, will be used as base forms.
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2. These forms will be covered with papiermache’ - torn strips of newspaper dipped in wheat paste.
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3. When dry and hard, these shapes may be painted.
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4. Using an xacto knife, they may be split in half horizontally.
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5. These models may then be filled with materials representing cell matter (the nucleus, protoplasm, chromosomes, etc.).
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6. The cell forms may be “hinged” on the inside using duct tape , enabling them to be easily opened and closed.
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7. The completed cell models might be displayed in the classroom or in an appropriate location within the school building, such as the library or a hallway display case.
Sample Project
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Unit Topic, Pregnancy
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This activity should be completed following study of the unit topic:
Prenatal Testing
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Directions
: Students, working together, will create a pregnancy timeline in the following manner:
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1. Tape or staple together nine pieces of colored paper (ex. pink, blue, yellow) alternating the three colors, to represent the three trimesters of pregnancy.
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2. Indicate week 1, 2, 3 etc. on the timeline by taping numbers across the top of the strip. (1-40)
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3. Using index cards, label and write a brief description of the following prenatal tests:
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Amniocentesis
13-15 weeks
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____
Chorionic Villi Sampling (CVS)
9-12 weeks
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Alpha-Feto Protein Screening (AFP)
15-18 weeks
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____
Ultrasound
may be used throughout, more often during midterm
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4. Tape the prenatal test cards to the timeline in the appropriate section.
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5. Display this “work-in-progress” in the classroom.
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6. Individual students may add their own prenatal testing dates, results or comments, as they feel comfortable.
Sample Test
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Unit Topic, Birth Disorders
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This test should be completed following study of the unit topic:
Birth Disorders.
Directions
: Match the disorder with the sentence. Write the correct answer on the line.
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1. Babies with this disorder cannot process a part of protein called phenylalanine _____ .
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2. This is a thyroid hormone deficiency that retards growth and brain development _____ .
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3. The major cause of this disorder is an extra chromosome 21 _____ .
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4. This is a birth defect of the backbone and sometimes the spinal cord _____.
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5. This disease occurs most frequently in descendants of Central and Eastern European Jews _____ .
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6. People affected with this disorder are often tall, slender, and loose-jointed _____ .
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7. This disease affects a protein inside the red blood cells _____ .
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8. It is a genetic disorder of bone growth that is evident at birth _____ .
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9. This muscle-wasting disorder affects boys almost exclusively _____ .
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10. The body produces large amounts of abnormally thick mucus because of this disease _____ .
muscular dystrophy PKU sickle cell disease
Down syndrome hypothyroidism Tay-Sachs spina bifida
achondroplasia Marfan syndrome cystic fibrosis