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Frequently Asked Questions - Pregnancy Tests


How reliable are the SERATEC® pregnancy tests?

The accuracy of the SERATEC® pregnancy Test is of 99 up to 100% when properly used. This leads to reliability as high as such of clinical studies.

At what daytime SERATEC® pregnancy tests should the be performed?

All SERATEC® pregnancy tests, exept the early tests may be performed anytime. Its high sensitivity allows for diagnostics without the need of first morning urine.
For the SERATEC® early pregnancy tests morning urine should be used!

How intensive should the colour of the indication line of a SERATEC® pregnancy test be as to mean a positive result?

The intensity of the colour depends on the concentration of HCG in urine samples. According to how advanced pregnancy is, as well as on the individual rate of production and attenuation, the membrane may turn from slightly pink up to darkly red. Even the lightest observable coloured line in the region of indication shows the presence of HCG and means therefore a positive result.

How long does the result of a SERATEC® pregnancy test remain observable?

The outcome of the SERATEC® pregnancy test may be observable for several years if the test is stored under dry conditions.

How may the result of a SERATEC® pregnancy test be influenced by consumption of medicaments?

The Test’s outcome is not influenced by the following substances:

  • Analgesics
  • Coffein
  • Antibiotics
  • Alcohol
  • Contraceptive pills
  • Vitamin C

    Medicaments containing HCG which are eliminated through the urine may influence the result of the Test, as well as medicaments which regulate the concentration of HCG.

    • How may the result of a SERATEC® pregnancy test be influenced by wrong use?

    The accomplishment of the Test is quite simple. Therefore its result is normally faultless. While the whole membrane turns slightly red during reaction, the colour fades away shortly afterwards.

    The result of the Test remains valid, even if the membrane is kept in the urine sample for more than 15 seconds or is exposed to a urine stream for over 8 seconds. Moreover, the result does not change even if it is read after a period longer than 3 minutes after its start. If the membrane is not impregnated sufficiently with urine, the Test may not be run correctly. Under these circumstances liquid residues may appear as lines („ghost lines“’), leading to an apparently positive outcome. This may be prevented for by exposing the Test to urine again immediately.
    The outcome may be apparently negative if it is read within a period shorter than the indicated.

    Exposure of the entire surface of the Test to the urine sample does not lead to failure.

    HCG concentrations lower than the minimum specified (10-25 mlU/mL) may show an apparently positive outcome past 15 to 30 minutes, especially when the Test is performed long before the end of the menstruation period.

    What causes are known to lead a SERATEC® pregnancy test to an apparently positive, wrong result?

    According to the scientific and technological state of the art it is most improbable to observe a wrong positive outcome. SERATEC® pregnancy tests are manufactured in accordance to the European Health Standards and submit to a severe quality control, to ensure that even a slight indication corresponds to a concentration of HCG higher than the normal. The most common reasons for a wrong indication are listed below:

  • Consumption of medicaments containing HCG.
  • Degeneration of the Plazenta following uncontrolled appearance of Corionzotes. Formation of Corionzotes results from the merge of two sperms with a Y-chromosome. Upon diagnose abnormally high HCG concentrations are observed as well as the fading of the ultrasound-image of the ovaries.
  • Chorio-carcinoma.
  • Hindered transport of the ovum through the fallopian tube leading to a nestling of the embryo.
  • Pregnancy interruption caused or followed by premature abortion. About one third up to half of all pregnant woman suffer a premature abortion within the first 12 weeks. So-called hindered pregnancies show a delayed evolution compared to normal. HCG secretion occurs at a lower rate leading to a smaller relative concentration. Furthermore HCG my be detected even after an abortion, as the time required for it to vanish varies individually.
  • Missed abortion.
  • Normal pregnancy stages menaced by abortion due to immunological failure.
  • „Ghost lines“(as stated above).
    • What causes are known to lead to an apparently negative, wrong result with pregnancy test?

    Wrong negative results may be due to different causes, too:

  • Running of the pregnancy test at too low HCG concentrations, in case of a premature measurement, or if ovulation occurs clearly towards the end of the period, or if a strong attenuation is caused by increased passing of water.
  • In the event of a mutated HCG detection. Only very few women show alterations in the binding positions of the HCG-Molecule, avoiding interaction with the specific antibody. In such cases a different test based on detection with a different antibody may of course have different outcome. This phenomenon is known in modern Medical Diagnostics as a consequence of the unique individual genetic and biological skills. Therefore no single immunological test is exempted from failure under these quite rare circumstances.
    • What may be reasons for failure of the SERATEC® pregnancy test?

    All sorts of membrane tests are highly sensible to humidity. The shelf life of the SERATEC® pregnancy tests may last up to several years as long as it remains sealed in a pouch containing a drying-gel envelope inside (standard packing conditions). Tests exposed to regular air humidity without being used may loose sensitivity after some hours and show only very thin lines in both the indication and the control regions, or no lines at all. Damage of the pouch may lead to loss of sensitivity as well. A severe quality control (manually performed) mostly prevents for the distribution of damaged Tests.

    How sensitive are the SERATEC® pregnancy tests upon temperature?

    The tests should be stored at temperatures between 2°C and 30°C. Temperatures below 0°C or above 30°C lead to a decrease of the shelf life. The regular period of 2 years cannot be guaranteed unless these conditions are observed. Beyond 60°C physical processes occur, which lead to the irreversible destruction of the Tests.
    Tests should be run at room temperature (between 18°C and 25°C) to avoid decreased sensitivity and flow rates of urine through the membrane.

    How do I have to dispose of the SERATEC® pregnancy tests?

    All SERATEC® pregnancy tests can be disposed of domestic waste and does not contain special waste like batteries.

  • SERATEC® Stick tests are manufactured with the minimum of required plastic. Only a very light protective foil has to be used.
  • SERATEC® Direct tests are consisting of a degradable cardboard housing containing the test strip.
  • SERATEC® Midsream and cassette tests have a plastic housing.