Pregnancy test Flashcards
test use to detect hCG
Pregnancy test
it is produces by syncytrophoblast cells ofthe placenta during pregnancy
hCG
identical to alpha-subunit of other hormones in the glycoprotein family, including LH, FSH and TSH
Alpha Subunit of hCG
determines the biological and immunological specificity of CG
Beta - subunit
what increases dramatically during the first trimester after reaching a peak at about 16 weeks gestitation
serum hCG
what subunit is present if the first trimester
beta subunit
what subunit appears in the 2nd trimester and steadily increase in last trimester
alpha subunit
what is a reliable indicator of pregnancy
elevated hCG in maternal and urine
reference interval of serum hCG
4-6mlu/ml
commonly measured by qualitative immunoassay test kuts with detection limits to approximately 20mlu/ml
urine hCG
when is can serum hCG detect the elevated hCG
4 - 6 days
when can urine hCG can be detected elevated hCG
2 - 3 days
what are the causes a false-positive result
ectopic pregnancy, germ cell tumor, gastational disease ect.
what causes a false negative result
early measurement after constipation, dilute urine, hoot effect
when a patient with early gestational vaginal bleeding or abdominal pain suggest
ectopic pregnancy or spontaneous abortion
- allows more accurate diagnosis and sound management than are obtained by clinical judgment alone
- can be use to detect intrauterine implantation
Quantitative measurement for pregnancy
what indicates abnormal pregnancy with 99% sensitivity
Increase in serum hCG of less than 53% in 2 days
what provides a greater than 80% probability of intrauterine implantation of fertilized ovum
doubling of hCG in 2 days
what could happen if there is failure to double the serum hCG
Ectopic pregnancy
best urine specimen for pregnancy
First morning specimen
