1. Ch. 4.3 Notes Problems in Prenatal Development

2. A.) Losing a Baby
Miscarriage: death of baby prior to the 20th week of pregnancy
Stillbirth: death of baby after the 20th week of pregnancy
15-20% of pregnancies end in miscarriage-Not all causes are known
2% of pregnancies end in stillbirth
Most common causes of stillbirth:
Problems w/placenta
Abnormal chromosomes
Poor growth
infections

3. 1.) Dealing with Grief Can be very unexpected and painful
Grief like the loss of the child that is already born
Feel alone may blame themselves for the death
Most couples who suffer miscarriage/stillbirth are able to have healthy children

4. B. Types of Birth Defects
Babies that survive pregnancy but are born with serious health problems that threaten their lives
Some birth defects are so mild no one would even know child has
Approximately 150,00 babies around the world are born each year w/a birth defect

5. Types and Causes of Birth Defects
Some birth defects cause abnormality in the structure of the body (misshapen foot/extra or missing finger)
Some birth defects cause one or more systems of the body to not function properly (blindness, deafness, mental retardation)
4 Main Causes:
Environmental
Heredity
Errors in Chromosomes
Interaction of Heredity and Environment

6. Environmental Causes
Developing baby depends completely on the mother’s body for nourishment and oxygen
Early development is critical, depends on choices mother makes (possibly before she knows she is pregnant)

7. Heredity Causes
Typically there are 5-6 imperfect recessive genes passed on
Recessive inheritance: when both parents pass of the same imperfect recessive gene, causes the baby to have the birth defect (Tay-sachs, cystic fibrosis)
Dominant Inheritance: child inherits defective gene that is dominant, only necessary to be passed on by 1 parent (Huntington’s disease)
Some only affect one sex (Hemophilia only is passed from mother to her sons)

8. Errors in Chromosomes Caused by # or structure of chromosomes
Error may occur when egg/sperms is developing (too few, too many or broken/rearranged chromosomes)
Not a hereditary defect
Most common=Down syndrome (extra copy of chromosome 21)

9. Interaction of Hereditary and Environment
Caused by combination of the 2
Cleft lip, cleft palate and spina bifida
For example: a genetic predisposition for spina bifida combined with the use of medications for the treatment of diabetes and seizure disorders during pregnancy, increases the likelihood of a child having the defect

10. Prevention and Diagnosis of Birth Defects
Before trying to conceive schedule a checkup to evaluate overall health
Discuss lifestyle changes (quit smoking/drinking)
Once pregnant visit a doctor for prenatal care (doctor monitors babies growth and development)
Abstain from alcohol, illegal drugs and tobacco
Discuss over the counter prescription medications

11. 1.) Genetic Counseling
Asses the risk of having a child with a birth defect caused by a defect in the genes
May be a history of birth defects in family
Some people may already have a child with birth defect and want to learn more about the risks
Specialist will do the following:
Evaluates family history
Complete physical examination of both parents
Samples of blood and body tissue are analyzed
Can only tell the risk for certain birth defects
Be aware of extra testing that may be done during pregnancy

12. 2. )Prenatal Test
100 kinds of defects can be detected before baby is born
Can help determine treatments done before and after birth

13. a. )Alpha-fetoprotein (AFP)
Blood test performed on mother between weeks
AFP protein produced in liver of fetus
Abnormal AFP can indicate a possible birth defect
Future testing can then be done to determine if birth defect exists and what it might be

14. b. ) Ultrasound
Uses sound waves to make video image called a sonogram of unborn baby
Helps
Monitor development of the baby
Determine certain birth defects
Detect problems with baby’s skeletal structure, circulatory or nervous system
Confirm due date
Confirm if there is 1 or more fetus’s
3. Done near 20th week
4. 3D ultrasounds can provide more detailed information

15. c.) Amniocentesis
Process of withdrawing a sample of the amniotic fluid surrounding the unborn baby
Doctor uses view from ultrasound to guide needle through the mother’s abdomen into the amniotic sac
Cells from fetus are in amniotic fluids and are tested for birth defects
Used as a test for Down Syndrome when mother is over 35
Used when there are questionable results of AFP blood test and ultrasounds
Involves some risk to the fetus and is performed only when there is a medical reason

16. d.) Chorionic villi sampling
uses a sample of the tissue from the membrane that encases the fetus to check for specific birth defects
samples of the tissue are snipped or suctioned off and analyzed
tests for the same disorders as amniocentesis but is used less often because risks are much greater
one advantage can be performed much earlier than amniocentesis

17. e.) Other Methods in experimental stages
possible to view fetus directly through laparoscope
obtain fetal blood and tissue
perform surgery on unborn child
carry a lot of risks