Genetics

Question 1

an anatomic or structual abnormality which is present at birth

Answer 1

Congenital malformation

Question 2

Percentage of perinatal deaths that are due to the presence of congenital malformations

Answer 2

20%

Question 3

Any substance capable of causing abnormal structure in an embryo

Answer 3

Teratogen

Question 4

Causes of congenital malformations

Answer 4

Genetic factors
Environmental factors
Multifactorial inheritance
Sensitive concept

Question 5

Certain structures are _________ to certain teratogenic agents at given times and only at given times. _______ event cannot influence the development of a structure if it occurs before or after that structure differentiates or develops

Answer 5

Sensitive,

Noxious

Question 6

The three catagories that teratogens are devided into are

Answer 6

1. Physical agents
2. Drugs and chemical agents
3. Maternal factors

Question 7

Radiation,
heat,
mechanical factors like uterine anomalies and fibroids

Answer 7

Physical agents (Teratogen)

Question 8

DES, Coumadin, alcohol, anti-thyroid drugs, methotrexate, retinoic acid/ vitamin A, valproic acid for seizures, trimethadione, thalidomide, methylmercury, and many others

Answer 8

Drugs and chemical agents (Teratogen)

Question 9

Include diseases such as diabetes and sickle cell anemia and maternal infections. There are many others

Answer 9

Maternal factors (Teratogen)

Question 10

Genetic defects that can be identified and diagnosed microscopically

Answer 10

Chromosomal abnormalities

Question 11

__________________ usually affect a large part of the fetus and Genome are associated with multiple anatomic abnormalities, mental retardation and high mortality rate

Answer 11

Major chromosome abnormalities

Question 12

Genetic diseases can be the result of:

Answer 12

• An abnormal number of chromosomes such as 13, 18, 21
• Abnormal structure of one or more chromosomes
• Single gene defects which are inherited as autosomal dominant or autosomal recessive

Question 13

First trimester testing is performed between ______ and _________weeks and involves two parts

Answer 13

11.5 and 13.5

Question 14

Types of genetic testing done during the firs trimester

Answer 14

• Nuchal translucency

* Maternal blood test of free or total beta hCG and PA PP- A (pregnancy associated plasma protein A)

Question 15

The combination of the two test done in the first trimester are done to test for

Answer 15

85% of Down syndrome (trisomy 21), & trisomy 18 (Edward’s syndrome)

Question 16

Measures the fluid filled area at the back of the neck between 11.5 and 13.5 weeks

Answer 16

Nuchal translucency screening

Question 17

In what plane is the Nuchal translucency screening done?

Answer 17

Sagittal

Question 18

How is the Nuchal translucency measured?

Answer 18

The measurement is taken inner to inner

Question 19

Nuchal translucency is normal if it is

Answer 19

less than 3mm

Question 20

The __________ which is ____________ to the fetus should not be mistaken for increased nuchal translucency

Answer 20

Amnion, adjacent

Question 21

If the Nuchal translucency is increased,

Answer 21

genetic testing of the fetus is performed

Question 22

If the fetus has a normal Karyotype

Answer 22

the fetus should be screened for cardiac abnormality in the mid-to-late trimester

Question 23

PA PP-A and beta hCG are produced by

Answer 23

trophoblastic tissue

Question 24

Low levels of PA PP-A and beta hCG may indicate

Answer 24

abnormal implantation
poor placentation
risk of trisomy 21

Question 25

An invasive test where a needle is placed within the uterine cavity via the cervix, and samples of the chorion or trophoblastic tissue, cells are obtained to evaluate for chromosomal abnormality

Answer 25

Chorionic villus sampling or CVS

Question 26

Testing done in the second trimester known as the quadruple is made up of what tests?

Answer 26

1. Maternal serum alpha-fetoprotein, MS AFP
2. Human chorionic godadotropin, hCG
3. Unconjugated estriol or E3
4. Inhibin A

Question 27

a glycoprotein which is produced primarily in the fetal liver. It crosses the placenta into the maternal serum and can easily be detected with a blood test called the maternal serum alpha-fetoprotein

Answer 27

Alphafetoprotein or AFP

Question 28

When can AFP be evaluated

Answer 28

• Incorrect dates (patient is further along in the pregnancy than she thought) *especially if AFP is decreased
• Multiple gestations
• Open neural tube defects
• Abdominal wall defects
• Sacrococcygeal teratoma in the fetus
• Maternal fetal hemorrhage
• Placental Chorioangioma

Question 29

Chromosome abnormalities

Answer 29

1. Fetal demise
2. Trisomy 21/ Down syndrome
3. Trisomy 18/ Edwards syndrome

Question 30

Increased MS AFP
Increased beta hCG
Decrease in E3
Increase in Inhibin A

Answer 30

Trisomy 21/ Down syndrome

Question 31

Decreased MS AFP
Decreased hCG
Decreased E3

Answer 31

Trisomy 18/ Edwards syndrome

Question 32

If the ultrasound evaluation fails to establish a cause for abnormal quadruple screen test, then __________ is offered to the patient to evaluate amniotic fluid levels of AFP and for fetal chromosome Karyotyping

Answer 32

Amniocentesis

Question 33

An invasive procedure whereby ultrasound is used to guide needle placement into the amniotic cavity

Answer 33

Amniocentesis

Question 34

When is an Amniocentesis performed?

Answer 34

at around 16 weeks