Lab Values Flashcards
TSH
1T: 0.1-4.4 (TSH production starts @ 12wk)
2T: 0.4-5.0
3T: 0.23-4.4
Term: 0.0-5.3
(TSH > ~5.3 = ABNORMAL)
*high TSH –> hypothyroidism?
Free T4
1T: 0.7-1.58 (T4 peaks at 12 wks)
2T: 0.4-1.4
3T: 0.3-1.3
Term: 0.3-1.3
*hyper vs. hypothyroidism,
subclinical hyperthyroidism
Total T4
1T: 3.6-9.0
2T: 4.0-8.9
3T: 3.6-8.6
Term: 3.9-8.3
Free T3
1T: 2.3-4.4
2T: 2.2-4.2
3T: 2.1-3.7
Term: 2.1-3.5
Total T3
1T: 71-175
2T: 84-195
3T: 97-182
Term: 84-214
Urine testing in pregnancy
Urine culture - dx & treat asymptomatic bacteuria
B-hCG normal ranges in 1st tri
- Can be detected in blood and urine 7-10 days after fertilization
- Doubles q2 days in 1T
- Peaks at 9-10 weeks
- Declines to nadir @ ~16-20 wks
1 wk: 5-50 IU/L 2 wks: 50-500 3 wks: 100-10,000 4 wks: 1,080-30,000 [discriminatory zone: ~5.5 wks, 1,500-2,000) 6-8 wks: 3,500-115,000 [9-10 wks PEAKS] 12wks: 12,000-270,000 13-16wks: up to 200,000
hCG patterns for multiples, ectopic, SAB
SAB
- hCG <1500 IU/mL + gestational sac
- Ectopic
- > 1500-2000, absent gestational sac
SAB & ectopic
Will fall or plateau, fails to reach 50% increase in 48 hrs
Abnormally high plasma hCG
- multiples
- erythroblastosis fetalis (associated with hemolytic anemia)
- gestational trophoblastic disease
- down syndrome
Screening for blood type and irregular antibodies
- Type and screen
- Indirect coombs test: mixing maternal serum w/ standard reagent that carries antigens –> +/- rxn w/ clinical significant. Unbound antibodies identified. only IgG abs are concerning, as IgM abs do not cross the placenta.
Rh-D negative management
- Rhogam (anti-D immune globulin) @ 28 weeks and 72 hrs after delivery
- Rhogam for anyone with risk of hemorrhage/bleeding
- prevents alloimmunization, which would cause increased risk of hemolytic disease to new born, hydrops.
WBC ranges
WBC 1T: 3.9-13.8 2T: 4.5-14.8 3T: 5.3-16.9 Term: 4.2-22.2
*Infection? think causes: respiratory, UTI/pyelo, VS, infectious diseases, etc.
Hgb & Platelet
PLATELET COUNTS 1T: 149-433 2T: 135-391 3T: 121-429 Term: 121-397
HgB / HCT 1T: 11.0-14.3 / 33-41 2T: 10.5-13.7 / 32-38 3T: 11.0-13.8 / 33-40 Term: 11.0-14.6 / 33-42
*Anemia – think MCVs, iron/ferritin, folate/B12 deficiencies, genetics for differentials
Iron and Ferritin normal ranges
Ferritin (ferriTEN) <10 = low
Iron <40 = low
*Iron deficiency anemia? Dx: Low hgb w/ serum ferritin <12
Folate and B12
Folate 1T: 2.3-39.3 2T: 2.6-15 3T: 1.6-40.2 Term 1.7-19.3
B12 LOW
1T <118
2T: <130
3T: <99
*folate deficiency? B12 deficiency? – also see CBC for macrocytic anemia
Albumin
Serum albumin decreases 0.5g/dL during 1st tri and by 0.75g/dL by term
1T: 3.2-4.7
2T: 2.7-4.2
3T: 2.3-4.2
Term: 2.4-3.9
Uric Acid
1T: 1.3-4.2
2T: 1.6-5.4
3T: 2.0-6.3
Term: 2.4-7.2
*High –> preeclampsia?
virtually all cases of preeclampsia correlates w/ disease severity, but not used for diagnosis
Hep B lab values
No hep B + immunity =
- negative HBsAg
- negative IgM anti-HBc
- Pos anti-HBs (developed immunity from vaccine)
Immunity from prev infection =
- positive anti-HBs
- positive anti-HBc
- negative HBsAG
Acute infection:
- positive HBsAg and anti-HBc
- anti-HBs negative
- HBsAg - surface marker on outside of Hep B virus, indicates acute or chronic infection and currently infectious. HBcAg - released within infected hepatocytes.
- HBeAg - viral replication during acute and chronic infection.
- anti-HBs - produced in response to recovery from B virus or immunity, developed in response to vaccine.
- anti-HBc - in response to Hep B infection, positive for life.
- anti-HBe - response to replicating HBe antigens, indicates clearance of virus or response to antiviral therapy.
- IgM anti-HBc - acute infection with Hep B within past 6 mo.
Hep C testing
Negative HCV: Negative HCV antibodies
Resolved HCV infection: Anti-HCV positive (confirmed), HCV RNA negative
Active HCV infection: Anti-HCV positive (confirmed), HCV RNA positive
Toxoplasmosis
Maternal
IgM & IgGs
Fetal: PCR test of amniotic fluid via amnio
Rubella
Maternal:
IgM
Fetal:
- detection virus via CVS or amniocentesis
- detect IgM via cordocentesis
HSV
Cell culture: culture of specimens from lesions of recurrent disease much less sensitive
- interpret +HSV cultures in context of clinical presentation b/c HSV may rarely be shed in chronic infection in absence of overt clinical disease
Serology: serologic testing has limited value for mgmt of acute infix; may be useful in assessing past infxn or patient’s risk for infxn
- Immunoblot IgG has sensitivity > 80% and specificity of 95%
Molecular dx-
NAAT techniques: may be used for detecting HSV DNA in tissue, CSF, and other specimen types
PCR = dx test of choice if CNS infxn suspected w/ sensitivity & specificity > 95%
Core labs-
pts w/ HSV encephalitis: CSF shows incr WBC count w/ mononuclear cell predominance; RBC count usually increased; CSF protein increase
Varicella and
Parvovirus
Serology IgG and IgM
Varicella
and
Parvovirus
Serology IgG and IgM
Initial prenatal visit labs
- CBC
- type & screen, antibodies
- Rubella
- RPR
- Hep B
- HIV
- Varicella
- UA/UC (Udip q visit)
- pap if needed
- For high risk –> GC/CT
High risk GDM:
- Hgb A1C
1st Trimester genetic screen
- CF, SMA, and other familial diseases
- NIPT / cell-free DNA: 9 wks GA to delivery (tests trisomies 21, 18, 13, and monosomy X)
- First trimester screen: 11-13.6 wks
- Serial sequential testing:
1. FTS 11-18 wks + US
2. Quad screen 15-21 wks
-For pt’s with + screening tests, amniotic fluid and chromosome analysis on chorionic villus sampling may be performed and is diagnostic.
1st Trimester genetic screen
- CF, SMA, and other familial diseases
- NIPT / cell-free DNA: 9 wks GA to delivery (tests trisomies 21, 18, 13, and monosomy X)
- First trimester screen: 11-13.6 wks
- Serial sequential testing:
1. FTS 11-18 wks + US
2. Quad screen 15-21 wks
-For pt’s with + screening tests, amniotic fluid and chromosome analysis on chorionic villus sampling may be performed and is diagnostic.
Mild Preeclampsia dx
Mild pre-eclampsia:
- BP >= 140/90 AND proteinuria
Proteinuria:
- 24-hr urine protein >= 300mg
- Protein:Creat ratio >0.3
- alternate test: >1+ by dipstick on 2 occasions >6hrs apart, but <1 week apart OR single specimen >=2+ by dipstick
In absence of proteinuria, can be HTN in association w/:
- thrombocytopenia (CBC + platelets)
- elevated ALT/AST to 2x normal concentration (LFTs)
- new renal insufficiency (Cr >1.1mg/dL or doubling of serum Cr in absence of other renal disease)
- draw HELLP labs
- uric acid almost always elevated, correlates with severity of disease
Severe Preeclampsia dx
- BP >160/110 on 2 occasions at least 6hrs apart
- Proteinuria of >5g/day
- Persistent visual or mental abnormalities, headache, RUQ pain, N/V, maybe edema
- draw HELLP labs to r/o
Mild Preeclampsia dx
Mild pre-eclampsia:
- BP >= 140/90 AND preoteinuria
- 24-hr urine protein >= 300mg
- Protein:Creat ratio >0.3
- alternate test: >1+ by dipstick on 2 occasions >6hrs apart, but <1 week apart OR single specimen >=2+ by dipstick
Severe Preeclampsia
-
gestational HTN
- Dx’d after 20 wks
- BP: 140-160 mmHg sys OR 90-110 mmHg dias AND elevated pressures on at least two occasions 4h apart but no more than 7 days apart
- no other s/s of proteinuria, cerebral sx, hemoconcentration, thrombocytopenia, hepatic dysfunction
chronic HTN
- dx’d before 20 wks
- BP: 140-160 mmHg sys OR 90-110 mmHg dias AND elevated pressures on at least two occasions 4h apart but no more than 7 days apart
- cerebral symptoms may or may not be present
- no other s/s of proteinuria, hemoconcentration, thrombocytopenia, hepatic dysfunction
GDM Screening Test
1 hr/ 50g test:
130-140 mg/dL
- -> 3 hr/ 100g test:
- FBG: 95-105
- 1hr: 180-190
- 2hr: 155-165
- 3hr: 140-145
Dx of GDM is made when any 2 values are met or exceeded in a 100-g, 3-hr test
- if pt has risk factors for DM, consider drawing HgbA1c with initial labs –> if A1c >= 5.7, then consider drawing random plasma glucose, 2 hr/ 75g OGT or fasting plasma glucose
Dx overt DM in early pregnancy
- fasting plasma glucose > 126 mg/dL
OR - HgbA1c > 6.5%
OR - 2hr OGT after 75g load (need 1+ abnormal value)
OR - random plasma glucose (>200mg/dL) in pt w/ classic symptoms
2hr/ 75g test values:
- fasting >= 92 mg/dL
- 1 hr >= 180 mg/dL
- 2 hr >= 153 mg/ dL
HELLP labs
HEmolytic anemia (CBC with peripheral smear, indirect and direct bilirubin)
Elevated Liver enzymes (ALT, AST)
Low Platelets - <100,000 (CBC w/ platelets)
Dx overt DM in Postpartum period
Dx:
- fasting plasma glucose >= 126 mg/dL
OR
- 2hr fasting plasma glucose >= 200 mg/dL
Impairment/increased risk for DM:
Impaired fasting plasma glucose: 100-125 mg/dL
Impaired glucose tolerance: 2h plasma glucose 140-199 mg/dL
