Prenatal labs

Question 1

normal values of Hb in pregnancy will reflect the ______

Answer 1

dilutional effect of greater plasma volume increase than red blood cell (RBC) mass.

Question 2

Because hemoglobin and hematocrit reflect pregnancy dilution, ________ may be the most reliable
predictor of true anemia.

Answer 2

MCV

Question 3

A low hemoglobin and low MCV (<80 mm3) most commonly suggests _________

Answer 3

iron deficiency, but may also be caused by thalassemia

Question 4

A low platelet count (<150,000/mm3) is most likely indicative of___________

Answer 4

gestational (pregnancy-induced)

thrombocytopenia

Question 5

White blood cell count in pregnancy is normally up to 16,000/mm3. Leukopenia suggests
__________

Answer 5

immune suppression or leukemia.

Question 6

The presence of rubella ________ rules out a primary infection during the pregnancy

Answer 6

antibodies

Question 7

Antibodies derived from a natural, wild infection lead to ___________ Antibodies from
a__________are not as durable.

Answer 7

lifelong immunity.

live-attenuated virus

Question 8

Rubella immunization is contraindicated in pregnancy because_________ but is recommended after
delivery.

Answer 8

it is made from a live virus

Question 9

_________are expected from a successful vaccination.

Answer 9

HBV surface antibodies

Question 10

_______ indicates high risk for vertical transmission of HBV from the mother to the fetus or neonate.

This is the only specific hepatitis test obtained routinely on the prenatal laboratory panel

Answer 10

HBV

surface antigen

Question 11

The presence of HBV ______ signifies a highly infectious state

Answer 11

E antigen

Question 12

The patient’s blood type and Rh is determined with the direct _________

Answer 12

Coombs test.

Question 13

If the patient is Rh negative, she is at risk for______

Answer 13

anti-D isoimmunization.

Question 14

The presence of atypical RBC antibodies is determined with the __________

Answer 14

indirect Coombs test.

Question 15

Screening cultures for________ and _______ will identify whether the fetus is at risk from
delivery through an infected birth canal.

Answer 15

chlamydia and gonorrhea

Question 16

Syphilis

Nonspecific screening tests _______ and ________ are performed on all pregnant women

Answer 16

veneral disease research laboratory [VDRL] or rapid plasma reagin [RPR])

Question 17

What to do for + screening tests for Syphilis

Answer 17

Positive screening tests must be followed up with treponema-specific tests (microhemagglutination assay for antibodies to T. pallidum [MHA-TP] or fluorescent treponema antibody absorption [FTA]).

Question 18

Syphilis

Treatment of syphilis in pregnancy requires ________to ensure adequate fetal treatment.

Answer 18

penicillin

Question 19

Urinalysis

Assessment of_________ is important to screen
for underlying renal disease, diabetes, and infection

Answer 19

proteinuria, ketones, glucose, leukocytes, and bacteria

Question 20

________ percent of pregnant women

have ASB.

Answer 20

Eight

Question 21

Left untreated, ______of ASB progresses to pyelonephritis, which is associated with septic shock, pulmonary edema, and adult respiratory distress syndrome

Answer 21

30%

Question 22

This screening skin test determines previous exposure to TB. A positive test is induration, not erythema

Answer 22

PPD or Tine test

Question 23

T or F

HIV screening is recommended for all pregnant women as part of the initial lab testing.

Answer 23

T

Question 24

HIV Testing

The CDC recommends ______

Answer 24

Informed Refusal (or “Opt Out,” where a patient is tested unless she refuses), rather than Informed Consent (or “Opt In,” where a patient must specifically consent).

Question 25

Rapid HIV testing in labor is recommended if the ____

Answer 25

patient’s HIV status is not known

Question 26

This screening test assesses presence of detectable HIV antibodies

Answer 26

ELISA test

Question 27

A ______ lag exists between HIV infection and a positive ELISA test

Answer 27

3-month

Question 28

T or F All babies born to HIV-positive women will be HIV antibody positive from passive maternal antibodies.

Answer 28

T

Question 29

This definitive test identifies the presence of HIV core and envelope antigens

Answer 29

Western blot test

Question 30

Triple antiviral therapy is recommended for all HIV-positive women starting at ______weeks and continuing through delivery.

Answer 30

14

Question 31

_______ can identify if the mother has cervical dysplasia or malignancy.

Answer 31

Cervical cytologic screening

Question 32

This is the major serum glycoprotein of the embryo. The concentration peaks at 12 weeks in the fetus and amniotic fluid (AF), then rises until 30 weeks in the maternal serum.

Answer 32

AFP

Question 33

__________) result in increased | spillage of AFP into the amniotic fluid and maternal serum.

Answer 33

Fetal structural defects (open neural tube defect [NTD] and ventral wall defects

Question 34

AFP changes Fetal serum Peaks at _______ Amniotic fluid Peaks at ______ Maternal serum Peaks at ______

Answer 34

12 weeks 12 weeks 30 weeks

Question 35

Other causes of high AFP

Answer 35

Other causes include twin pregnancy, placental bleeding, fetal renal disease, and sacrococcygeal teratoma

Question 36

_____is reported in multiples of the median (MoM) and is always performed as part of multiple marker screenings

Answer 36

MS-AFP

Question 37

A positive high value for MS-AFP is ______

Answer 37

>2.5 MoM

Question 38

The most common cause of an elevated MS-AFP is | ________

Answer 38

dating error.

Question 39

MS-AFP Testing In cases of dating error, what to do?

Answer 39

repeat the MS-AFP if the pregnancy is still within the 15- to 20-week window

Question 40

MS-AFP If the dates are correct and no explanation is seen on sonogram, perform ______ and _____

Answer 40

amniocentesis for AF-AFP determination and acetylcholinesterase activity.

Question 41

Elevated levels of _______ | activity are specific to open NTD

Answer 41

AF acetylcholinesterase

Question 42

With unexplained elevated MS-AFP but normal AF-AFP, the pregnancy is statistically at risk for________

Answer 42

intrauterine growth restriction (IUGR), stillbirth, and preeclampsia.

Question 43

Low MS-AFP A positive low value is _______

Answer 43

<0.85 MoM

Question 44

The sensitivity of MS-AFP alone for trisomy 21 is only | ______

Answer 44

20%.

Question 45

The most common cause of a low MS-AFP is ______

Answer 45

dating error

Question 46

MS-AFP If the dates are correct and no explanation is seen on sonogram, perform _______

Answer 46

amniocentesis for karyotype.

Question 47

The sensitivity for trisomy 21 detection can be increased to 80% by performing maternal serum screen for not only MS-AFP, but also ______, _______ and ______ The window for testing is also _______

Answer 47

hCG, estriol, and inhibin-A 15–20 weeks

Question 48

With Down syndrome, levels for MS-AFP and estriol are decreased, but ______ increased

Answer 48

hCG and inhibin-A are,

Question 49

Next step if suspected DS or Edwards

Answer 49

Perform an amniocentesis for karyotype.

Question 50

With Edward syndrome, levels for __________ are | decreased. Perform an amniocentesis for karyotype.

Answer 50

all 4 markers (MS-AFP, estriol, inhibin-A, and hCG)

Question 51

This screening test is administered to all pregnant women between 24 and 28 weeks’ gestation. No fasting state is needed. A 50-g glucose load is given, and serum glucose is measured 1 h later.

Answer 51

1-h 50-g oral glucose tolerance test (OGTT )

Question 52

1-h 50-g oral glucose tolerance test (OGTT ) A normal value is _____ If abn, _________

Answer 52

<140 mg/dL. 3-h 100-g OGTT

Question 53

This is the definitive test for glucose intolerance in pregnancy

Answer 53

3-h 100-g OGTT

Question 54

An FBS >125 mg/dL indicates ________

Answer 54

overt diabetes | mellitus, and no further testing is performed.

Question 55

If the FBS is <126 mg/dL, administer _______

Answer 55

a 100-g | glucose load, followed by glucose levels at 1, 2, and 3 h.

Question 56

What are the N values for 1 hr OGTT

Answer 56

Normal values are FBS <95 mg/dL, 1 h | <180 mg/dL, 2 h <155 mg/dL, and 3 h <140 mg/dL.

Question 57

1 hr OGTT ______ is diagnosed if ≥2 values are abnormal. _______ is diagnosed if only 1 value is abnormal.

Answer 57

Gestational diabetes Impaired glucose intolerance

Question 58

A complete blood count (CBC) should be performed between ________’ gestation in all women

Answer 58

24 and 28 weeks

Question 59

Reason for anemia in 3rd trimester

Answer 59

With the increasing diversion of iron to the fetus in the second and third trimester, iron deficiency, which was not present early in pregnancy, may develop

Question 60

Before giving prophylactic RhoGAM to an Rh-negative woman, an indirect Coombs test is performed at _____

Answer 60

28 weeks

Question 61

Reason for need to do Atypical Antibody Screen

Answer 61

This is obtained to ensure she has not become isoimmunized since her previous negative AAT earlier in pregnancy

Question 62

T or F If it is discovered that the patient already has anti-D antibodies, administration of RhoGAM is futile.

Answer 62

T