The pregnancy test is a test that there measures the human gonadotropinacoriónica(GCH), which is a hormone produced during the pregnancy. The gonadotropinacoriónica appears in the blood and in the urine of the pregnant women from 10 days after the conception.
A test or test of pregnancy can be realized using blood or urinates and two types of this test exist:
Qualitative: that measures if the hormone GCH is or do not present.
Quantitative: that measures how many hormone GCH is present.
The blood test is done extracting only one blood pipe and sending it to the analysis laboratory. His prosecution is realized and as it the results can be had on the following day.
The test of the human gonadotropinacoriónica in the urine (commonly called gravindex) is carried out by means of the application of a drop of urine in a band or prepared chemical strip, which generally throws the result in one or two minutes and is compared by a positive witness. If the color is equal it is considered to be a positive, and if it is not colored just as the witness is considered to be a denial.
The result can be Positivo or Negative being normal both in the qualitative skill. The pregnancy tests in urine will be only positive when the person has enough GCH in the blood. If the pregnancy scarcely begins and the GCH level is below 25-50 mlU/ml, the test will be negative and it can be pregnant, then before a clear pregnancy suspicion it is necessary to repeat spent a few days.
The GCH levels in the quantitative skill increase in rapid form during the first trimester of the pregnancy and then they diminish slightly.
WEEKS OF PREGNANCY
STATUS mIU/ml.
3 - 4
9 - 130
4 - 5
75 - 2,600
5 - 6
850 - 20,800
6 - 7
4,000 - 100,200
7 - 12
11,500 - 289,000
12 - 16
18,300 - 137,000
16 - 29
1,400 - 53,000
29 - 41
940 - 60,000
The GCH levels must rise every 48 hours up to the beginning of the pregnancy and when the above mentioned levels do not rise appropriately, this can be an indication of a problem in the pregnancy. Some problems associated at a level of GCH abnormally high include miscarriage and pregnancy ectópico(tubárico).
The extremely high GCH levels can suggest the presence of a pregnancy molar or of more than one fetus, for example, twins.
DEFINITION 
