Upload
hector-charles
View
219
Download
0
Embed Size (px)
Citation preview
Chapter 4.2Problems 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