How do Pregnancy Tests Strips Work?

May 30, 2011

Quick Bites:
  • For accurate results, pregnancy test kit must be used in the morning.
  • Test kits recognise the presence of hCG in the urine.
  • hCG is produced by the growing embryo i.e. it is preset only during pregnancy.
  • Pregnancy test kits give results in just 5 minutes.

First things first, pregnancy test strips work by detecting pregnancy hormone from a woman's urine sample. This hormone, called hCG or human chorionic gonadotropin, is a glycoprotein hormone that is produced by the developing embryo during pregnancy.

After six days of conception, the fertilised egg implants the uterus and in the process produces hCG. However, it is evident from many studies that in ten percent of women implantation occurs even after the first day of missed period. But,  in all the cases, the level of hCG builds up rapidly everyday.


Using the Pregnancy Test Strips

  • Pregnancy test strip must be preferably used in the morning for more accurate results. This is because first morning sample has highest concentration of hCG level.
  • Urinate into a clean cup.
  • Dip the test strip into urine sample and ensure that you hold them vertically.
  • Wait for few seconds until you notice red dye moving towards the result window.
  • Within 5 minutes you can read the result.


Reading the PregnancyTest Results

While you are waiting to read your pregnancy test results you will notice a coloured solution moving across the test area towards result area. This migration is normal and indicates that test is progressing correctly. Wait for few minutes (according to time mentioned in the manual).

  • If only one line appears in the ‘control zone’, test is negative and you are not pregnant
  • If one line appears in the ‘control zone’ and the other in the result area then the test is positive and you are pregnant.
  • However, there may be chance that you get no band in the result area of strip. This may be due to your inability of following instructions or insufficient amount of urine specimen.

When checking for pregnancy with the help of a pregnancy test kit, it is important for you to follow the instructions as mentioned on the label.


Read more articles on Pregnancy Test.