Pregnancy Test (Human Chorionic Gonadotrophin)
Type of test: Blood; urine
All pregnancy tests are based on the detection of HCG, which is secreted by the placental trophoblast after the ovum is fertilized. HCG will appear in the blood and urine of pregnant women as early as 10 days after conception. In the first few weeks of pregnancy, HCG rises markedly, and serum levels are higher than urine levels. After about a month, HCG is about the same in either specimen.
Type of test: Blood; urine
All pregnancy tests are based on the detection of HCG, which is secreted by the placental trophoblast after the ovum is fertilized. HCG will appear in the blood and urine of pregnant women as early as 10 days after conception. In the first few weeks of pregnancy, HCG rises markedly, and serum levels are higher than urine levels. After about a month, HCG is about the same in either specimen.
- Immunologic test (agglutination inhibition test (AIT) (blood and urine)
Immunologic tests are performed by using commercially prepared antibodies against the HCG molecule. With the development of monoclonal antibodies, immunoassays can identify very small levels of HCG, and pregnancy can be detected 3 to 7 days after conception. Several immunologic tests are now commercially available for testing by the public.
- Radioimmunoassay (RIA) (serum)
The RIA is a highly sensitive and reliable blood test for the detection of beta unit of HCG. This study requires a blood sample; however RIA also may be performed with a urine test. This test is so sensitive that pregnancy can be diagnosed before the first missed menstrual period.
- Radioreceptor Assay (RRA) (serum)
The RRA for serum HCG is highly sensitive and accurate. The major advantage of this study is its reliable diagnosis of early gestation in patients requesting an early termination of pregnancy and in cases in which infertile couples are anxious to confirm pregnancy.
Human Placental Lactogen (Human Chorionic Somatomammotropin)
Type of test: Blood
The human placenta produces several hormones that are homologous to hormones of the anterior pituitary. Not surprisingly, hPL demonstrates both lactogenic and growth stimulating activity. Serum levels of hPL rise very early in normal pregnancy and continue to increase until a plateau is reach at about the 35th week after conception. Assays for maternal serum levels of hPL are useful in monitoring placental function. Measurements of hPL also are used in pregnancies complicated by hypertension, proteinuria, edema or possible miscarriage.
References:
http://www.labtestsonline.org/understanding/analytes/hcg/test.html
http://www.netlib.org/benchmark/hpl/
http://www.ovulation-calculator.com/files/hcg.gif
Diagnostic and Laboratory Test Reference by Mosby's
Human Placental Lactogen (Human Chorionic Somatomammotropin)
Type of test: Blood
The human placenta produces several hormones that are homologous to hormones of the anterior pituitary. Not surprisingly, hPL demonstrates both lactogenic and growth stimulating activity. Serum levels of hPL rise very early in normal pregnancy and continue to increase until a plateau is reach at about the 35th week after conception. Assays for maternal serum levels of hPL are useful in monitoring placental function. Measurements of hPL also are used in pregnancies complicated by hypertension, proteinuria, edema or possible miscarriage.
References:
http://www.labtestsonline.org/understanding/analytes/hcg/test.html
http://www.netlib.org/benchmark/hpl/
http://www.ovulation-calculator.com/files/hcg.gif
Diagnostic and Laboratory Test Reference by Mosby's
