Which NLU has the lowest cutoff

Pregnancy test: when does it start working?

Did it work out? Different pregnancy tests can tell you whether you are expecting a baby. But which test is right for you? How does a urine test work? And: under what circumstances can the result be wrong?

How does a pregnancy test work?

All pregnancy tests work on the same principle. They measure the hormone HCG. Since this hormone is only produced during pregnancy, if it is detected at a certain concentration, it means that you are pregnant. HCG is therefore also called the pregnancy hormone. The abbreviation stands for Human Chorionic Gonadotropin.

What types of pregnancy tests are there?

The home pregnancy test is the urine test. It is available as an early pregnancy test and as a classic pregnancy test. The early test can indicate an existing pregnancy before the missed menstruation, with the classic variant you have to be patient until the second day after the missed period (also NMT for non-mens day). But the result is more reliable.
Your gynecologist can also do a blood test in the practice. This test can also indicate pregnancy before the expected menstrual period.
Pregnancy tests also differ in the way they display the results. Analog tests show you whether the test was negative or positive by the appearance or non-appearance of bars. This is the case with both paper test strips and those with plastic housings. For most tests, one bar means “not pregnant” and two bars mean “pregnant”. However, please read the instructions on the package carefully before testing so as not to misinterpret the result.
Digital pregnancy tests are clearer. With a laughing smiley face or the words “pregnant” or “not pregnant” you know clearly whether the result is positive or negative. Some digital tests also tell you the week of pregnancy.

By the way: In medicine, the first week of pregnancy begins on the first day of the last menstrual period. According to this usage, the weeks count towards pregnancy before fertilization has even taken place. This often leads to confusion, because a pregnancy test with a week specification shows you the 2nd to 3rd week, but the doctor speaks of the 5th week of pregnancy later.

A little digression on the pregnancy hormone HCG

The pregnancy hormone HCG (human chorionic gonadotropin) is formed from the cells of the early mother cake. The hormone has an alpha and a beta subunit. The beta-HCG (also β-hCG) gives the hormone its specific character. In the following we limit ourselves to the name HCG.
HCG stimulates the ovaries to produce estrogen and progestin and prevents menstruation from occurring. Its most important task is to keep the pregnancy going.
After implantation, the HCG level increases by leaps and bounds. If the HCG concentration in a non-pregnant woman is still 5 mlU / ml (Milli-International Units per milliliter), it increases to up to 50 mlU / ml five days after implantation. It doubles about every two days, although the concentration varies greatly from person to person. In the 7th week of pregnancy, it can be between 3,700 and 164,000 mlU / ml in the blood. Due to the rapid increase, the measurement of the HCG level is so well suited for the early detection of pregnancy. The maximum HCG concentration is reached between the 8th and 12th week of pregnancy. The ovaries no longer have to be stimulated to produce hormones, as the formed placenta now takes on this task itself.
The value can now drop so far that a conventional pregnancy test is negative or only slightly positive.
By the way: It is believed that the high HCG concentration is responsible for the typical morning sickness. If the HCG level drops, the nausea also subsides.

When does a pregnancy test start working?

A normal urine test can detect the HCG hormone from a concentration of 25 mIU / ml. Your body reaches this value about two days after the embryo has implanted in the uterus. This usually corresponds to the day of the missing menstrual period. The test result is safer if you manage to wait an extra day or two.
The test has a reliability of 95 to 99 percent. The further the pregnancy has progressed, the safer the result. If the test is positive, you can have it confirmed by your gynecologist.

Overview: What can which test do?

Type of test

Time of possible evidence

Blood test at the doctor

from the 9th day after ovulation

Home early pregnancy test

from the 10th day after ovulation

Normal urine test to take at home

from the 14th day after ovulation

When should I take a test?

A pregnancy test is useful if you have missed your period and you notice other early signs of pregnancy. Couples wanting to have children will routinely do it in each cycle and hope that the result will be positive. But if you don't want a child at all, you will surely hope that it is negative. Should you still be pregnant, you can turn to one of the many counseling centers that will help you deal with this stressful situation. Have a look at www.profamilia.de.

Where can I get a pregnancy test from?

Urine tests are available over the counter. You can get them in pharmacies and drug stores. The conventional tests are available from four euros. The digital version is a bit more expensive.

How do I do the urine test?

Testing itself is very easy. You simply hold the tip of the pregnancy test in your urine stream. Alternatively, you can collect the urine in a clean beaker and soak the test for about 20 seconds. The package insert will tell you how long you have to wait for the result. It is usually only a few minutes.
When the urine comes into contact with the test strip, the enzymes on the test react with the hormone HCG in the urine. Depending on the concentration of the hormone, the bar or the cross in the result window changes color or triggers the digital display. The bar in the control field only shows whether the test worked at all. He appears first.
A weak bar can also be a positive test result. To be on the safe side, you should repeat the test a few days later.
By the way: A test is only meaningful for about ten minutes. Then the test strip reacts with the air, with moisture and the urine dries up. This can cause the bar to fade or disappear, which doesn't mean you are no longer pregnant! Even digital tests can no longer be read after a few days. It's best to take a photo of the fresh test and throw the good piece in the trash yourself. Then at least you have a picture for your baby memory box.

When do I take the pregnancy test?

The HCG concentration is highest in the morning urine because you did not drink any fluids at night. So after getting up is the best time to take the test. If you work at night, it is best to test after a long period of rest. Your morning urine is then the urine that you give up after sleeping. Even if the clock says something else.

When does an early pregnancy test make sense?

Have you wanted a baby for a long time and can hardly wait until the day of your hopefully missed period? Then you can also do an early pregnancy test. It is more sensitive than conventional tests and measures an HCG concentration from 10 mlU / ml. An early test can show you whether you are pregnant four to six days before you miss your menstruation (10 days after ovulation). Because the HCG level rises just five days after implantation. One week before the missed period, it is between 5 and 50 mlU / ml. It is different for every woman. Therefore, it can also happen that even a sensitive early test with the lowest detection limit (also called cutoff) does not indicate a pregnancy in you, even though you are pregnant.
Unfortunately, the early test has one disadvantage: A positive test result confirms that you are pregnant at this point in time. However, in the first few weeks of pregnancy, the fertilized egg can come off with the next menstrual period. That would make it clear that you had an early miscarriage. A knowledge that would burden you very much and let you look to the future with new worries. Of course, a miscarriage can happen even after a normal pregnancy test. But it is much more likely in the first few days of pregnancy.

Can a pregnancy test give an incorrect result?

A pregnancy test is usually very reliable, but in rare cases it can also lead to a false-positive or false-negative result. So the test can show you are pregnant even though you are not. And it can indicate that you are not pregnant even though you are expecting a child.

General causes of a wrong result:

  • Incorrect handling (e.g. too short immersion)
  • Exceeding the expiry date
  • Incorrect storage
  • Test not performed at room temperature
  • Taking medication (e.g. antidepressants)

Causes of a false positive result

  • After fertilization and implantation, the embryo has not developed any further (early miscarriage).
  • Taking drugs that contain HCG. These are administered e.g. during artificial insemination (IVF, ICSI). This is where the test should be done by your doctor.
  • Some cancers lead to increased HCG production.
  • The body also produces more HCG during kidney failure or menopause.
  • Some tumors produce HCG (but this is very rare).

Causes of a false negative result

  • The strip was in the urine too long.
  • The test was carried out before the HCG level was sufficient for the test in question (repeat the test after a few days!).
  • The due date for the menstrual period was calculated incorrectly (then the test may no longer be negative in a few days).
  • The HCG level fell again during the course of pregnancy.
  • Night shift work falsifies the result if testing is carried out in the morning (test here after longer periods of rest!).
  • Bacteria in the urine can lead to a false negative result.

When is an additional blood test necessary?

The concentration of HCG in the blood of a pregnant woman is higher than in the urine. Therefore, a blood test a few days before the missed period (nine days after fertilization) can relatively reliably prove pregnancy.
A blood test has more diagnostic options. It can determine the age of the embryo and is often used when it is not clear whether the pregnancy is intact. In order to determine, for example, whether an ectopic pregnancy or a molar bladder is present, two measurements are necessary every 48 hours.
Several measurements also have the advantage that they make the development of the HCG concentration visible. A steady increase in values ​​is more meaningful than a single measured value.
If there is no therapeutic need, the health insurers usually do not cover the costs (around 35 euros) for the blood test. Your gynecologist will certainly first do a urine test in the practice.

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