1. Influences on Birth Defects

2. FACTS About 150,000 babies are born each year with birth defects.
The parents of one out of every 28 babies receive the frightening news that their baby has a birth defect
There are over 4,000 known birth defects
Birth defects are the leading cause of death in the first year of life.

3. What is a Birth Defect?
An abnormality of structure, function or body metabolism (inborn error of body chemistry) present at birth that results in physical or mental disability or is fatal

4. Environmental Influences on Birth Defects
Inadequate nutrition of mother
Exposure to diseases or infections during pregnancy
Harmful substances consumed during pregnancy

5. Environmental Influences on Birth Defects
Inadequate nutrition of mother
Stunted brain development of baby
Leads to mental retardation
Increased risk of multiple birth defects and low birth weight

6. Environmental Influences on Birth Defects
Exposure to diseases or infections during pregnancy
Rubella, or German Measles, can cause blindness, deafness, heart disease, and mental retardation
Toxoplasmosis, can cause hearing loss, learning disabilities and death; found in cat litter and some raw meats
Chicken pox, scarring of babies’ skin, limb defects, eye problems, and miscarriage
STDs can be passed to unborn child and lead to serious illness, physical disabilities, or death
Most primary infections produce no symptoms. The time between exposure to the infection and symptom development is weeks. The disease can affect the brain, lung, heart, eyes, or liver.
Toxoplasmosis is found in humans worldwide, and in many species of animals and birds. Cats are the definitive host of the parasite.
Human infection may result from:
Blood transfusions or solid organ transplants
Carelessly handling cat litter
Eating contaminated soil
Eating raw or undercooked meat (lamb, pork, and beef)
Toxoplasmosis also affects people who have weakened immune systems.

7. Environmental Influences on Birth Defects
Harmful substances consumed during pregnancy
Nicotine from smoking tobacco or secondhand smoke
Smaller babies
Miscarriages and premature births
Respiratory infections or allergies

8. Environmental Influences on Birth Defects
Harmful substances consumed during pregnancy
Alcohol can cause fetal alcohol syndrome (FAS)
20% of infants die
Facial deformities, delayed physical growth, heart defects, and hyperactivity
Mental retardation or disabilities
Poor coordination
Difficulty controlling behavior

9. Environment Influences of Birth Defects
Harmful substances consumed while pregnant
Drugs
Over-the-the counter drugs
Drug addiction
Long-term learning and behavioral problems
Risk of miscarriages
Congenital heart problems
Pass on drug addiction to the baby, makes it necessary for baby to go through painful withdrawal period after birth

10. Environmental Influences on Birth Defects
Exposure to hazards during pregnancy
Chemicals-
Types of paint, pesticides, lead- based chemicals, carbon monoxide, mercury, solvents, paint thinners, and formaldehyde
X-rays
Cause cancer, miscarriages, and mental retardation
Toxoplasmosis – extreme high blood pressure

11. Environmental Influences on Birth Defects
Accidental injuries
Cerebral palsy caused by damage to brain before, during, or shortly after birth
Falls lead to a variety of complications

12. Hereditary Influences on Birth Defects
Dominant genes?
Recessive genes?
Can you explain the difference?
Dominant is stronger, the weaker gene is recessive

13. Hereditary Influences on Birth Defects
1. Defective recessive genes inherited from both parents
Cystic fibrosis- caused by inheritance of recessive genes; more likely to affect Caucasians
Tay-Sachs disease- an inherited disease most common among Eastern European families of Jewish descent
Sickle cell anemia- malformed red blood cells that deprive the body of oxygen and prevalent in African Americans
2. Defective dominant gene inherited from one parent
Hemophilia- passed on from mothers to sons only; prevents blood from clotting
Huntington’s disease- manifest in adulthood, leads to dementia
Duchenne muscular dystrophy- transmitted by female carriers, usually affects only males
Color blindness- usually affects only males
3. Errors in chromosomes- error in number
Down syndrome- associated with mental retardation, increased risk of heart defects, leukemia, poor muscle tone, and distinctive physical characteristics

14. Combined Influence of Heredity and Environment Birth Defects
Drugs + virus = heart defect
Cleft lip/cleft palate- gap in upper lip or palate
Spina Bifida – reduce risk by taking folic acid

15. What potentially causes birth defects?
A single abnormal gene can cause birth defects
Every human being has about 100,000 genes that determine traits such as eye color, hair, etc

16. Can birth defects be prevented?
While the potential causes of most birth defects are not known, there are a number of steps a woman can take to reduce her risk of having a baby with a birth defect.
Visit doctor regularly, take vitamins, avoid alcohol, smoking, prescription drugs

17. Factors that contribute to Birth Defects:
Overweight
Underweight
Jewish descent
African-American

18. Visit a health care provider for a pre-pregnancy check up, especially if a woman has health problems
When pregnant take daily multivitamins containing 400 mg of the B-vitamin folic acid
Avoid alcohol, drugs, smoking, prescription or over-the-counter medication unless approved by a health care provider

19. More factors that contribute to birth defects
Drinks alcohol
Uses prescription drugs
Has used street drugs
Takes vitamins
Drinks caffeine
Has had exposure to chemicals

20. More factors that contribute to birth defects
Lives in a home built before 1955 (lead paint)
Constant exposure to cats
Has had x-rays during pregnancy
High blood pressure
Diabetes
Sickle cell anemia

21. More factors that contribute to birth defects
Health problems
Genital herpes
Gonorrhea
Syphilis
No immunizations against rubella
Miscarriage

22. Can some birth defects be diagnosed before birth?
Yes
Ultrasound
Amnicentesis
Chronic villus sampling

23. Can birth defects be treated before birth?
Some, prenatal therapy
Prenatal surgery- urinary tract blockages, rare tumors in the lungs, spina bifida, ph disease

24. Review How do you define birth defect?
What factors contribute to birth defects?
Can some birth defects be diagnosed before birth?
Can birth defects be prevented?
Resources:

25. Group Project
Make a pamphlet that you would see in a doctors office for pregnant women to give them information about birth defects