Prenatal Testing - Standard Testing

Question 1

Can every birth defect be detected with prenatal testing?

Answer 1

No, most complex genetic conditions can’t be detected with current technology. Anything that isn’t present at birth or environmental factors influence its development also can’t be detected

Question 2

What is prenatal testing?

Answer 2

Testing for the presence of certain medical conditions during pregnancy

Question 3

What are screening tests?

Answer 3

Tests that indicate a likelihood of a medical condition

Question 4

What are diagnostic tests?

Answer 4

Tests that confirm the presence or absence of a medical condition

Question 5

Are all medical conditions present at birth?

Answer 5

No, most aren’t

Question 6

Are all medical conditions due to genetic causes only?

Answer 6

No, most have environmental influences. Some are due to genetic causes though

Question 7

What are false positives?

Answer 7

When a test indicates a condition is present when it isn’t

Question 8

What are false negatives?

Answer 8

When a test indicates that everything is fine when a condition is present

Question 9

Why would a parent choose to do prenatal testing?

Answer 9

1. Information to be better prepared
2. To decide if they want to terminate the pregnancy
3. Reassurance that everything is fine

Question 10

Which medical conditions are routinely tested for during pregnancy?

Answer 10

The 3 autosomal trisomies

Question 11

What are the 3 commonly used routine screening tests?

Answer 11

1. Maternal serum tests
2. 1st trimester ultrasound
3. 2nd trimester ultrasound

Question 12

What do maternal serum tests measure?

Answer 12

Levels of certain enzymes and biochemical markers associated with certain genetic conditions. Not a genetic test

Question 13

What is the risk with maternal serum tests?

Answer 13

High rates of false positives and false negatives

Question 14

When are maternal serum tests done?

Answer 14

In the 1st and 2nd trimesters

Question 15

Are maternal serum tests screening or diagnostic tests?

Answer 15

Screening

Question 16

What does a 1st trimester ultrasound measure?

Answer 16

Certain characteristics associated with genetic characteristics

Question 17

What are the risks with a 1st trimester ultrasound?

Answer 17

High levels of false positives and false negatives

Question 18

Is 1st trimester ultrasound a screening or diagnostic test?

Answer 18

Screening

Question 19

What does a 2nd trimester ultrasound measure?

Answer 19

Does a full anatomical scan to make sure anatomy is all there, position of the placenta, twins. Looks for reduced size that may indicate a trisomy

Question 20

What are the risks for a 2nd trimester ultrasound?

Answer 20

Reasonably high levels of false positives and false negatives

Question 21

Is 2nd trimester ultrasound a screening or diagnostic test?

Answer 21

Screening

Question 22

Why are only trisomy 21, 18, and 13 screened for? Why not other trisomies?

Answer 22

21, 18, and 13 are the only trisomies that result in a viable embryo. They also happen, but result in a miscarriage due to being inviable

Question 23

What is trisomy 21? What are the symptoms? What is the life expectancy?

Answer 23

Down syndrome. Symptoms range from mild to severe intellectual disability and mild to severe medical complications. Now people with Down syndrome can live to 60 and later, but early 1900s only survived until about 10

Question 24

Why did the life expectancy for people with Down syndrome increase?

Answer 24

Inclusion. In the early 1900s, people were put in institutions and social isolation and didn’t receive the care they needed. Now progress in health care allows them to get the care they need to survive

Question 25

What is trisomy 18? What are the symptoms? What is the life expectancy?

Answer 25

Edward’s syndrome. Has much more severe intellectual disabilities and medical complications than trisomy 21. Very few survive their first year and even rarer to survive to adulthood, most people with the condition die within their first week

Question 26

What is trisomy 13? What are the symptoms? What is the life expectancy?

Answer 26

Patau syndrome. Has much more severe intellectual disabilities and medical complications than trisomy 21. Very few survive their first year and even rarer to survive to adulthood, most people with the condition die within the first 10 days