Ch. 4.3 Notes Problems in Prenatal Development

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

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

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

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

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)

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)

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)

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

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

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

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

a. )Alpha-fetoprotein (AFP) Blood test performed on mother between 15-20 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

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

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

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

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