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Chapter 4.2. Problems in Prenatal Development . Losing A Baby . Expecting Mothers worry about the health of the newborn. Miscarriage: the developing baby dies prior to the 20 th week of pregnancy Fairly common: 15% of pregnancies
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Chapter 4.2 Problems in Prenatal Development
Losing A Baby • Expecting Mothers worry about the health of the newborn. • Miscarriage: the developing baby dies prior to the 20th week of pregnancy • Fairly common: 15% of pregnancies • Still Birth: when the developing baby dies after the 20th week. • 2% of pregnancy
Dealing with Grief • Very unexpected and painful for the parents. • Attachment during pregnancy • Grief similar to the loss of a child already born • Support
Birth Defects • Some babies survive pregnancy but with serious problems. • 120,000 babies are born each year in the United States with birth defects
Types and Causes of Birth Defects • Not all birth defects are obvious at birth; sometimes it may takes years for them to be discovered. • Scientists do not fully understand the causes for most birth defects; so far they have determine that there are 4 main causes • 1. Factors in the Environment • 2. Hereditary • 3. Errors in Chromosomes • 4. Combination of Environmental and Hereditary
Environmental Causes • Early development of embryo is critical • 1. Nutritional Balance • 2. Diseases or infections the mother has during pregnancy • 3. Harmful Substances • Alcohol, Tobacco, Over-the-Counter Meds, Illegal Drugs • 4. Medications • 5. Air Pollution • 6. Exposure to X-Ray or high levels of radiation
Birth Defects • Cerebral Palsy • Cleft lip/palate • Cystic Fibrosis • Down Syndrome • Muscular Dystrophy • PKU • Sickle Cell Anemia • Spina Bifida • Tay-Sachs
Hereditary Causes • Half of the genes from mother; half from father • Normal for a child to get 5-6 imperfect recessive genes • If they receive the same faulty gene from both parents this may cause the child to have a birth defect. • Recessive inheritance • Tay-Sachs and Cystic Fibrosis • Sometimes a child will inherit a defective gene that is dominant • Only needed from one parent • Dominant inheritance • Huntington's Disease (middle age) • Hemophilia-prevents blood from clotting • Color Blindness
Errors in Chromosomes • Several types of birth defects are caused by chromosomes. • An error may occur when the egg or sperm are developing. • Too many or too few chromosomes • Down Syndrome • May have some degree of mental retardation and physical problems • 1 in 800 babies • Extra copy of chromosome 21; so instead of having 2 copies- they have three. • Higher risk for mothers who have children over the age of 35
Interaction of Heredity and Environment • Combination of heredity and environmental factors • Example: • Inherit a tendency that may lead to heart defect and drug use will bring out that tendency earlier. • Cleft lip/Palate and Spina Bifida are examples • Inherited traits along with the use of certain medications, infections, illnesses, or tobacco and alcohol.
Prevention and Diagnosis • Not all causes of birth defects can be anticipated or controlled. • Several things couples can do to lessen the chances • Checkups- Evaluate their overall health before conceiving • Lifestyle Changes (Before Pregnant) • Woman unaware of being pregnant • Once pregnant • Visit physician • Prenatal care • Avoid substances
Genetic Counseling • History of birth defects • Family history • Already have a child with birth defects • Counseling can explain options and risks • Physical Exam • Blood Samples • Testing
Prenatal Tests • More than 100 kinds of birth defects can now be detected before a baby is born. • Alpha-fetoprotein (AFP) • Performed 15-20 weeks. AFP is a protein in the liver of the fetus. Abnormal levels can indicate birth defects. • Ultrasound • Is a test that uses sound waves to make a video image of the unborn baby. • Image is called a sonogram • Amniocentesis • Withdrawing amniotic fluid surrounding the baby. • Cells are taken in for testing • Involves some risk to the fetus and is performed only when necessary
Prenatal Test Continued • Chorionic Sampling • Uses a sample of the tissue from the membrane that encases the fetus to check for specific birth defects. • This is used less often because it has higher risks ; but can be done much earlier than amniocentesis • New Prenatal Diagnosis • Several methods are now in experimental stages • Someday provide more accurate information