Seminar 2

We will get started right at 7:00.

Genetics, Prenatal Development, & Birth

• Genetic Screening– What is it? • Systematic screening of one or both parents to

determine prenatal susceptibility. – Why do it?• To know in advance the chance of having a baby

born with a disorder.– How is it done?• Family history assessment and blood testing for

carriers of specific genes.

http://www.merckmanuals.com/home/sec22/ch256/ch256b.html

What is Cystic Fibrosis?

• Inherited, chronic disease that makes the body create a very thick mucus which fills the lungs and keeps the body from absorbing food.

• The result of a recessive gene.– lung problems/breathing problems– lack of growth and lack of weight– early death

What if this recessive gene is found in both parents?

• 25% chance the child will have CF• 50% chance the child will not have CF but will

carry the recessive gene• 25% chance the child will not have CF and will

not carry the recessive gene

Prenatal Testing of CF

• Amniocentesis• Chorionic Villus Biopsy

DB Topic 1Genetic disorders or abnormalities in children usually cannot be prevented, but some can be identified before birth; risk factors for these problems can also be identified before a pregnancy occurs. There are several types of genetic problems that can occur and several types of tests the parents can have to check for potential genetic problems. Consider the scenario below and then answer the questions based on the course material for this unit.

•Scenario: John and Sue are planning to have their first baby and they know they both have a history of cystic fibrosis in their families of origin. They are not pregnant yet. Their doctor advises that they undergo genetic testing and counseling to determine the risk that the baby will be born with the disease. They are unsure whether or not they want to have the testing.

What are the pros and cons of John and Sue having the testing in terms of the deciding if they should or should not get pregnant?

If they decide to have the testing and find out that one or both of them is a carrier of the disease and they decide to have a baby anyway, could they find out before the baby is born whether or not the baby has the disease? If so, what types of tests are used to answer this question and what are the risks?

Low Birth Weight Babies

Low Birth Weight Risk FactorsPremature Babies:

Had a previous premie Pregnant with multiples Have an abnormal cervix or uterus

Full-term SGA: Babies with birth defects Mother has chronic health problems Alcohol/drugs/smoking Uterine or placental infections Lack of weight gain by the mother SES

LBW Outcomes• Increased risk for cerebral palsy• Lower IQs• Increased risk of learning disabilities• Increased risk of physical/motor problems• Lower grades in school• More acting out in school• Hearing problems• Health problems

LBW Prevention

• Prenatal care– access– quality

• Healthy mother• Maternal nutrition/micronutrition• Maternal monitoring• No teratogens

LBW Developmental Interventions

• Oxygen• Nutrition • Home visits• Parental resources• Early identification and treatment of

developmental delays• Speech therapy• Occupational therapy

Low Birth Weight DB#2Low birth weight babies fall well below the optimal range of weight for a healthy baby and are usually considered premature. As such, these babies tend to have medical and other developmental problems, many of which can put them at serious risk. Several factors have been identified that can lead to low birth weight in infants. Additionally, medical treatments and other interventions have been shown to have a positive impact on improving outcomes for babies that are low birth weight.

1. Based on the course material, describe at least two risk factors for low birth weight or prematurity and one possible outcome of low birth weight on a baby’s development.

2. Give examples of two different types of interventions that would either prevent low birth weight or help the infant develop.

Teratogens

• The focus of the Unit 2 seminar is to investigate the way that teratogens are harmful to the baby during prenatal development. Teratogens are different from genetic disorders because they can be prevented most of the time. Many of these toxins can have a devastating effect on the child. To prepare for Seminar, please review the Key Concepts section in the Readings link of this unit to learn more about teratogens.

Teratogens• Genetic inheritance is transmitted to the child through

chromosomes from the mother and father in complex patterns that include dominant/recessive, polygenetic, multifactorial, and sex-linked factors.

• Problems during prenatal development can occur due to genetic abnormalities or environmental toxins called teratogens, but many of these can be prevented or identified through testing. Some examples of teratogens include: radiation, lead, PCB's and other chemicals found in paints and dyes, chemicals found in household cleansers and cosmetics, food additives, artificial sweeteners and chemicals used in cosmetics.

• Every major system is in place during prenatal development by the end of the embryonic stage and refinement of the systems takes place during the fetal stage, which is the longest.

Teratogens

• There are many choices for women to make when they give birth including the location of the birth, who is present, and whether to use different medical interventions.

• Complications during pregnancy and birth can lead to low birth weight babies who are born prematurely and present specific challenges to health care professionals and the families of these children.

And always remember ….

• I am here to support you through this course. • I want you to enjoy this course and do well.• Let me know if you have any questions or problems.