Screening & Diagnostic Testing (exam 1) Flashcards
Blood Type and Rh factor
Purpose:
- ABO typing is performed on first visit to determine the client’s blood type in the ABO antigen screen
Rh typing is done to determine the woman’s blood type in the rhesus antigen system
- Rh positive indicates the presence of the antigen
- Rh negative indicates its absence
Comments:
If the client is Rh negative and has a negative antibody screen -> receives Rh immune globulin
- After 26-28 weeks gestation
- After any invasive procedure (amniocentesis)
Antibody Screen
- Indirect Coombs for RBC antibodies on Rh negative clients
- Rubella (Immunity)
Purpose:
Previous sensitization with rh+ antigen mean antibodies are present and harmful to this baby
If the rubella titer is negative (lower that 1:10 d/L), indicating susceptibility to the rubella virus, the patient should receive the immunization postpartum.
- NEVER during pregnancy
Comments:
The client must be using effective birth control at the time of immunization
- She is counseled not to become pregnant x3 months (live vaccine)
Hemoglobin & Hematocrit
Purpose:
Both levels with decrease during gestation as a result of increased plasma volume (pseudo anemia)
Hemoglobin:
A decrease in Hgb to less than 10 g/dL -> anemia
Hematocrit:
A decrease in Hct to less than 30% -> anemia
Comments:
Pseudoanemia does not require tx
True iron-deficiency anemia is treated specifically with oral or injections of iron preparation.
- All pregnant women are encouraged to take 30 mg Iron
Sickle cell screening
Purpose:
Indicated for clients at risk for sickle cell
Comments:
Increased volume = increased pain
Tuberculin skin test
Purpose:
Positive test indicates need for chest x-ray to r/o active disease
- May be delayed until after delivery
Comments:
In pregnant client, x-ray is not performed until after 20th week
Gonorrhea and Chlamydia
Purpose:
Vaginal culture during initial examination and may be repeated in 3rd trimester for high-risk individuals
Comments:
Both infections cause ophthalmic scarring in the baby
- Neonate receives application of antibiotic in both eyes at birth
Herpes Virus
Purpose:
A culture is indicated for client with a positive hx or those with active lesions
- The test is performed to determine the route of delivery
Comments:
Cesarean delivery if active lesions present or suspected at time of delivery
- Acyclovir is NOT a cure
Syphilis
Purpose:
A culture is performed if chancre (sore) is present
- Diagnosis is dependent upon culture and serology (VDRL or RPR)
Comments:
Syphilis must be treated by 18-20 weeks gestation so that fetus does not acquire congenital syphilis
Urinalysis & Urine Culture
Purpose:
A urine specimen for glucose and protein determinations should be obtained at every prenatal visit
Comments:
Dipstick at each visit
Glucose (UA)
Purpose:
Glycosuria is a common result of decreased renal threshold that occurs during pregnancy
- If it persists, it may indicate diabetes
Comments:
All pregnant women are screened with a 1hr glucose tolerance test at ~24 weeks gestation
- At risk clients are scheduled at initial prenatal visit
- If 1hr test is failed, will require 3hr test
Protein (UA)
Purpose:
Levels of 2+ to 4+ protein in the urine may indicate infection or preeclampsia
Comments:
All infections are investigated, but UTIs are associated with PTL
Ketones (UA)
Purpose:
Ketonuria may result from insufficient food intake or vomiting (as in hyperemesis)
Comments:
All infections are investigated, but UTIs are associated with PTL
WBCs (UA)
Purpose:
WBCs in urine may indicate infection
Comments:
All infections are investigated, but UTIs are associated with PTL
Hep B Surface Antigen
Purpose:
Identifies carriers of Hep B
- Recommended for all clients because of the prevalence of the disease
- Vaccination indicated for at-risk populations
Comments:
At-risk populations may be screened again in 3rd trimester
