Transcript CD ch 4-3 powerpoint - Fairfield Public Schools

Problems in Prenatal
Development
Miscarriage and Birth Defects
Losing a Baby
• Miscarriage: If the developing baby dies
before the 20th week of pregnancy.
15 to 20 percent of recognized
pregnancies end in miscarriage.
• Stillbirth: If the baby dies after the 20th week
of pregnancy
This occurs in about 2% of pregnancies
common causes: abnormal chromosomes
poor growth
infections
problems with the placenta
Dealing with Grief
• Parents go through stages of grief
– Similar to losing a child that has been born
Types of Birth Defects
• Birth Defects: babies that are born with
problems that threaten their health or
their lives.
• Hundreds of types
• Some mild - barely noticeable
• Some severe - lifelong
• Some birth defects cause an
abnormality in the structure of the body.
– Ex. Misshapen foot
Missing finger
• Others cause one or more body
systems not to function properly
– Ex. Blindness
Mental retardation
• Some birth defects are apparent at
birth
• Others are not discovered until
months or years later
Achondroplasia
Cerebral Palsy
Cleft Palate
Clubfoot
Cystic Fibrosis
Down Syndrome
Fifths Disease
Fragile X Syndrome
Gastroschisis
Hemophelia
Huntington’s Disease
Hydrocephalus
Marfan Syndrome
Muscular Dystrophy
Phenylketonuria (PKU)
Progeria
Rh Disease
Sickle Cell Disease
Spina Bifida
Tay-Sachs Disease
Causes of Birth Defects
•
Environmental Causes
**THE BABY’S ENVIRONMENT**
(womb)
- poor nutrition of mother
- diseases or infections of mother
- harmful substances taken by mother
ex: alcohol, drugs
- medicines taken by mother
- exposure to hazards
ex: X rays, chemicals
• Hereditary Causes:
– When a child inherits a defect from its parents.
• Ex: cystic fibrosis - If both parents
pass on a recessive gene for
the disease, the baby will get
the disease.
• Errors in Chromosomes:
– Due to problems in the number or structure of
chromosomes. Not hereditary, because neither
parent has the abnormal chromosome.
– Ex. Down Syndrome - an extra copy of
chromosome 21.
• Interaction of Heredity and Environment:
– Some birth defects are caused by a combination of
heredity and the environment. For example, a child
may inherit a tendency for a birth defect. If an
environmental factor exists, the baby will have the
defect.
– Ex. Cleft palate and cleft lip
Spina bifida
Prevention & Diagnosis of
Birth Defects
• Prospective parents should get regular health
checkups.
• Avoid smoking, drugs & alcohol
• Genetic Counseling:
– Genetic counselors can inform couples of their
chances of having a child with certain birth
defects. They will not be told what to do - just
what the options and risks are.
Prenatal Tests
• Alpha-fetoprotein (AFP):
– Blood test performed on mother
• It checks the levels of AFP being
produced by the fetus. Abnormal levels
can mean a birth defect.
• Ultrasound:
– Uses sound waves to make a video image
of the developing baby. Some birth
defects can be detected with an ultrasound
picture (sonogram).
• Amniocentesis:
Taking a sample of the amniotic fluid that
surrounds the developing baby. This is usually
used to test for Down Syndrome when the
mother is over 35.
• Chorionic villi sampling:
– Takes a sample of the tissue in the placenta.
Used less often, due to greater risks.
– Can be used earlier than amniocentesis.