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Every woman wants to know as early as possible whether conception has occurred. The level of development of modern medicine makes it possible to do this without going to the doctor, using an inkjet test. This device allows you to determine pregnancy in the early stages and do it at home.
The inkjet test is one of the varieties of the express pregnancy diagnostic system, which is more advanced than conventional test strips. The main difference between the inkjet device is that it can be used almost anywhere and anytime.
The principle of operation of inkjet pregnancy tests
Inside the device itself, a rod is built in, which consists of microfibers. Between these fibers there are small tubules, it is through them that urine will rise up. When it reaches the part of the device where the reagent is located, the strips are stained. If a woman’s urine contains a hormone called chorionic gonadotropin, it will attach itself to the latex parts inside the test. Staining of the desired strip will occur if the level of the hormone in the urine exceeds 10-25 mIU / ml.
It is known that the level of the hormone hCG in a non-pregnant woman is 5 mIU / ml. After the fertilized egg attaches to the wall of the uterus, the body begins to produce this hormone in large quantities. Already 4 days after the implantation of the embryo into the uterus, the hormone level rises to 10 mIU / ml, and after 14 days it reaches 25 mIU / ml. It is the latter indicator that is the lower threshold of sensitivity for most inkjet tests. However, some manufacturers claim that their systems are capable of detecting the hormone in urine even as low as 10 mIU/mL.
Types of inkjet tests
The most common inkjet tests are disposable express strips, which have a sensitivity of 10 mIU / ml or more. Also on sale there are devices that can be used several times. To do this, they are equipped with removable cassettes.
In addition, inkjet digital tests can be found. Instead of a strip with a developing indicator, the device has an electronic display. There may be two or one such windows. The final result is indicated in the first window: the inscription “pregnant” or “not pregnant” appears, and the second display is a control one. It is necessary in order to make sure that the procedure is carried out correctly.
Some inkjet digital tests are additionally equipped with a USB port. If the test is connected to a computer, you can read not only the result, but also see the expected date of birth. Also, the program automatically determines the gestational age. The most popular brands of inkjet tests are: Evitest, Duet, Home Test, Clearblue, etc.
Advantages
Inkjet tests are among the most accurate instruments. They are guaranteed to give reliable results. The error (subject to all operating conditions) is no more than 1-2%.
For many women, it is very important that you can find out the result in advance, without waiting for the first expected day of menstruation. To get this opportunity, it is necessary to choose inkjet tests with increased sensitivity – 10 mIU / ml.
Another advantage of inkjet tests lies in their name, that is, to perform the test, you just need to substitute it under a stream of urine. This allows you to perform diagnostics almost anywhere, anytime.
Disadvantages
As for the shortcomings of inkjet tests, there is only one – the high price of the device. Depending on the complexity of the device, it may increase. Accordingly, the most expensive are inkjet tests with an electronic scoreboard and a USB port. The cheapest are the usual inkjet test strips.
How to use the inkjet test correctly?
The rules for operating inkjet tests are almost the same for all similar devices. There may be minor differences in the interpretation of the results, which will be indicated in the instructions for use. It can be found inside each package with the device.
Using inkjet tests is very easy, just follow these steps:
It is necessary to open the package, take out the device and remove the protection from the handpiece, if any.
The test is taken in the hand and brought under the stream of urine, tip down.
The liquid must be on the tip. Most often after that it changes color.
Keep the tip under the stream of urine for about 5-10 seconds. The exact time will be indicated in the instructions for use.
Then the test is laid out on a dry, flat surface with the window up.
After 3-5 minutes, evaluate the result.
As a rule, one bar indicates that there is no pregnancy, and two bars mean that the woman is pregnant. Sometimes a second band appears, but its color is very faint. Most often, this means that the pregnancy still occurred, however, it is better to repeat the test after a few days. This will ensure a positive result.
When the test is equipped with a digital display, the words “pregnant” or “not pregnant”, or the signs “+” or “-” may appear on the screen.
It also happens that the test does not show any values. In this case, either the device was faulty, or the procedure itself was carried out with violations, for example, urine fell on the handpiece in insufficient volume.
Can an inkjet pregnancy test give a false result?
Under the condition of correct operation of the device, the probability of obtaining an unreliable result is minimized.
The reasons why data may be distorted are as follows:
The woman took the test too early, and the concentration of hCG in the urine has not yet reached the desired level.
Ovulation did not occur in the middle of the cycle, but a little later.
The test was overdue. Therefore, before buying, be sure to check the release date of the test and its expiration date.
Testing was not done in the morning. The fact is that the maximum concentration of the hormone in the urine is observed precisely in the morning, immediately after waking up. During the day, a woman can drink plenty of fluids, or take diuretics. All this contributes to the dilution of urine and may adversely affect the reliability of the result.
Sometimes the test shows not only a false negative, but also a false positive result, this happens in the following situations:
The woman is being treated for infertility. Often the composition of drugs includes hormones, including hCG.
A woman develops a hormone-producing tumor.
The woman has recently had a miscarriage or had an abortion.
The woman had an ectopic pregnancy. In this case, pains in the lower abdomen of a aching nature often appear, and discharge mixed with blood is also disturbing.
When the test gives a negative result, but menstruation does not begin, it is necessary to retest after a few days. If it again indicates the absence of pregnancy, then you must definitely consult a doctor, but even if a positive result is obtained, a gynecologist’s consultation is also necessary.