Influences on

Birth Defects

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.

What is a Birth Defect?

Environmental Influences on

Birth Defects

� Inadequate nutrition of mother

� Exposure to diseases or infections

during pregnancy

� Harmful substances consumed during

pregnancy

Environmental Influences on

Birth Defects

Inadequate nutrition of mother

�Stunted brain development of baby

�Leads to mental retardation

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

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

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

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

Environmental Influences on

Birth Defects

Exposure to hazards during pregnancy

� Chemicals

� X-rays

� Toxoplasmosis – extreme high blood

pressure

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

Hereditary Influences on

Birth Defects

Dominant genes?

Recessive genes?

Can you explain the difference?

Hereditary Influences on

Birth Defects

1. Defective recessive genes inherited from both parents

• Cystic fibrosis

• Tay-Sachs disease

• Sickle cell anemia

2. Defective dominant gene inherited from one parent

• Hemophilia

• Huntington’s disease

• Duchenne muscular dystrophy

• Color blindness

3. Errors in chromosomes

• Down syndrome

Combined Influence of Heredity

and Environment Birth Defects

� Drugs + virus = heart defect

� Cleft lip/cleft palate

� Spina Bifida – reduce risk by taking

folic acid

What potentially causes birth

defects?

� 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.

Can birth defects be

prevented?

Factors that contribute to

Birth Defects:

• Overweight

• Underweight

• Jewish descent

• African-American

Brainstorm

� 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

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

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

More factors that contribute

to birth defects

� Health problems

� Genital herpes

� Gonorrhea

� Syphilis

� No immunizations against rubella

� Miscarriage

Can some birth defects be diagnosed before birth?

Can birth defects be treated before birth?

Preventing Birth Defects

•Avoid…

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?