Problems in Prenatal Development. Miscarriage Loss of a baby PRIOR TO the 20 th week of pregnancy.

Problems in Prenatal Development

Miscarriage

• Loss of a baby PRIOR TO the 20th week of pregnancy.

Stillbirth

Death of a baby AFTER the 20th week of pregnancy.

Birth Defects

PKU

• Inability of body to process a common protein.

Sickle Cell Anemia

• Malformed red blood cells interfere with oxygen supply.

• http://www.webmd.com/video/sickle-cell-miracle

Tay-Sachs Disease

• Lack of a certain blood chemical makes body unable to process certain fats in the brain and nerve cells.

Down Syndrome

• Extra chromosome 21 typically results in mental retardation.

• http://www.webmd.com/video/down-syndrome-test

Causes of Birth Defects

Environment

• Poor nutrition

• Diseases

• Harmful substances

• Medicines

• Exposure to hazards such as radiation

Heredity

• Inheritance of two defective recessive genes.

• Inheritance of one defective dominant gene.

Errors in Chromosomes

• Having too few or too many chromosomes, broken or rearranged chromosomes.

Interaction of Heredity and Environment

• Inherited genetic predisposition toward a defect coupled with exposure during pregnancy to certain medications, infections, or harmful substances.

What does a Genetic Counselor Do?

• Uses information from physical exams and medical history to assess a couple’s risk for having a child with certain birth defects.

Prenatal Tests

Alpha-fetoprotein (AFP)

• Mother’s blood is tested to detect abnormal levels of protein AFP

• No known risk

Ultrasound or sonogram

• Sound waves are used to make a video image of the unborn baby.

• No known risk

• http://www.muschealth.com/video/Default.aspx?videoid=10055

Mrs. Cissel’s Grandson

Baby Cohen

Amniocentesis

• A small amount of amniotic fluid is removed and tested.

• Some risk to fetus.

• http://www.muschealth.com/video/Default.aspx?videoid=10055

Chorionic Villi Sampling

• Samples of tissue from the membrane that encases the fetus are removed and tested.

• Greater risk than amniocentesis

• http://www.muschealth.com/video/Default.aspx?videoid=10055

Avoiding Dangers to the Baby

Alcohol• Fetal Alcohol Syndrome

– Incurable condition found in some children of mothers who consumed alcohol during pregnancy

– Wide range of physical and mental disabilities that last a lifetime

– Facial deformity, delayed physical growth, heart defects, & hyperactivity

• Mental retardation and severe learning problems

• Alcohol interferes with tissue growth and development

• Brain tissue is easily injured by alcohol

• Poor coordination and difficulty controlling behavior

Other Harmful Drugs• Medicines – both over-the-counter and

prescription• Caffeine – found in some foods and

beverages • Nicotine and other toxic chemicals

found in cigarettes• Illegal drugs and inhalants

X Rays

• Radiation can cause birth defects

Hazardous Chemicals and Substances

• Paint• Pesticides used to exterminate bugs• Lead (in water and paint)• Carbon monoxide• Mercury (found in fish, such as swordfish and

shark)• Solvents, paint thinners, and formaldehyde

(used in some workplaces)

Infections

• Some pose a greater risk than others

Rubella• Can cause severe birth defects

• First three months most critical– Blindness– Deafness– Heart disease– Mental retardation

Toxoplasmosis• An infection caused by a parasite• Can cause blindness, hearing loss, & learning

disabilities• Death or long-term mental disabilities• Miscarriage or stillbirth• A pregnant woman should never clean a cat’s

litter box, eat undercooked meat, and should wash hands thoroughly and immediately after touching raw meat.

Chicken Pox• If an expectant mother gets chicken pox

during the first half of her pregnancy, her baby is at slight risk of getting a condition called “congenital varicella syndrome”– Scarring of the skin, limb defects, eye

problems, and other serious abnormalities, miscarriage

Sexually Transmitted Diseases• Some can be passed on to the child

during the birth process– Syphilis, gonorrhea, hepatitis B, genital

herpes, AIDS, and Chlamydia– Newborns are treated with a solution that

will kill any gonorrhea germs that could cause blindness

AIDS• 35 to 65% risk the virus will be passed

on to the baby.

• Attacks the brain

• The infected babies often have seizures and retarded mental development.