Obstetric 3

Question 1

pregnancy and radiography

Answer 1

• avoid plain film radiographs in 1st trimester, esp trunk or back
• abdominal lead shield gives some protection

Question 2

pregnancy and CT

Answer 2

not recommended in any trimester

Question 3

pregnancy and MRI

Answer 3

considered low risk and preferential to CT

Question 4

pregnancy and dx ultrasound

Answer 4

• commonly used, but video display may increase thermal effects
• esp in 3rd trimester

Question 5

dilutional anemia =

Answer 5

increased blood volume, even with compensatory increase in EPO and RBCs

Question 6

EPO/RBC norm for pregnancy:

Answer 6

~ 10.5 g/dL

Question 7

EPO/RBC norm for normal women:

Answer 7

~ 12-16 g/dL

Question 8

chorionic villus sampling used for

Answer 8

early detection of genetic disorders

Question 9

chorionic villus sampling risks

Answer 9

1-2% chance of miscarriage

Question 10

amniocentesis performed when

Answer 10

16-18 weeks

Question 11

amniocentesis risks

Answer 11

• most sources cite 0.5-1% chance of miscarriage

- depends on baby health, timing, high risk pregnancy

Question 12

What is done in chorionic villus sampling?

Answer 12

• sample of chorionic villi are removed from the placenta for testing
• taken through cervix or abd wall
• usu performed at 10-13 weeks

Question 13

What are chorionic villi?

Answer 13

• wispy projections of placental tissue

- share the baby’s genetic makeup

Question 14

How is an amniocentesis performed?

Answer 14

amniotic fluid removed from uterus for testing or treatment

Question 15

Why is an amniocentesis performed?

Answer 15

• genetic testing
• fetal lung testing
• dx of fetal infection
• tx

Question 16

When is amniocentesis used as tx?

Answer 16

can accumulate too much fluid and some must be drained

Question 17

precautions with pregnancy and lactation: drugs

Answer 17

• anything that can cross the placental barrier may be harmful to the baby
• restrictions during lactation

Question 18

What types of restrictions during lactation are there for drugs?

Answer 18

• if allowed, should be taken 30-60 minutes after breastfeeding AND
• 3-4 hrs before next feed

Question 19

What are the FDA categories in pregnancy?

Answer 19

Category A
Category B
Category C
Category D
Category X

Question 20

Category A pregnancy

Answer 20

controlled human studies show no fetal risks

Question 21

Category B pregnancy

Answer 21

animal studies show no fetal risks (no human studies available)

Question 22

Category C pregnancy

Answer 22

• no adequate human or animal studies

- risk cannot be ruled out

Question 23

Category D pregnancy

Answer 23

• evidence indicates fetal risk

- benefits thought to outweigh the risks

Question 24

Category X pregnancy

Answer 24

• contraindicated in human pregnancy

- risks outweigh any potential benefits