Pregnancy Tests

Are you pregnant, or think your teen may be pregnant? This article compares pregnancy tests and offers information on the accuracy of the different types of pregnancy tests. Keep reading to discover how pregnancy tests work and which are the most reliable tests.

Are you pregnant? Although it is certainly true that after a certain point a pregnancy test such as an ultrasound would show the presence of a baby, thus confirming a pregnancy, when people say “pregnancy test” they mean a noninvasive test that is done early in a pregnancy before other visible signs have manifested. This article gives an overview of pregnancy tests. 

What Is a Pregnancy Test? 

A pregnancy test is a method of determining whether a hormone called human chorionic gonadotropin (hCG), or “the pregnancy hormone” is present in a woman’s body. The presence of this hormone only comes about during pregnancy. A woman’s body begins to produce hCG when a fertilized egg implants in her womb. It then builds as the duration of the pregnancy lengthens. 

Types of Pregnancy Tests 

The hormone hCG can be detected either in a woman’s blood or in her urine. To have a blood pregnancy test requires a trip to a lab where blood is drawn or to a doctor’s office. There are two types of hCG blood pregnancy tests: qualitative and quantitative. A qualitative test only measures to see if hCG is present. It simply tells if a woman is pregnant or not. The quantitative test (also called a beta hCG test) finds the precise amount of hCG in the blood. But a home pregnancy test (HPT), which uses urine for its test, can be purchased inexpensively and performed at home or any other place with a bathroom. This gives the user more flexibility and privacy. 

Accuracy of Pregnancy Tests 

The accuracy of a pregnancy test depends on several factors including carefully following the particular test’s written instructions, the test product itself, how quickly the fertilized egg implants, the time of day the test is used, etc.: 

  • Home pregnancy tests have an expiration date. Make sure to check it.
  • Home pregnancy tests require waiting ten minutes to read results. The results are most accurate at this time.
  • Home pregnancy tests may not detect low levels of hCG early in pregnancy, and if they do, results may be faint and misread.
  • Fertilized eggs implant at different times. Often, implantation occurs about 6 days after fertilization. But according to the National Women’s Health Information Center, for up to 10 percent of women, it takes longer, and implantation may not happen until after the first day of a missed period.
  • Some brands of pregnancy tests are more sensitive.
  • Pregnancy testing with urine upon first arising in the morning may yield more accurate results.
  • The “control indicator” is present in home pregnancy tests to let you know if the test is working properly. If you do not see the control indicator, you may not have accurate results.
  • In general, home pregnancy tests carry a disclaimer that you should always repeat the pregnancy test after a few days for confirmation.  This helps avoid incorrect conclusions from false negatives, for whatever reason.
  • A problem with the pregnancy, such as an ectopic pregnancy, can affect the amount of hCG in the urine, hence the test result.
  • Medicines used to treat infertility may contain hCG and can produce a false positive result on an pregnancy test.  
  • Drinking large amounts of fluids can dilute the hCG levels, making it more difficult to read the test results. 

How to Use a Home Pregnancy Test 

Home pregnancy tests have slightly different approaches, depending on the brand. For some, a specially prepared stick or strip of paper is held in the urine stream. In others, the urine is collected in a cup and the stick or strip is then dipped in or a dropper is used to transfer the urine. Also, the length of time one must wait for results differs, as does the indication that you are or aren’t pregnant. The most obvious have the words “not pregnant” or “pregnant,” while other tests show a symbol, line or other result indicator. 

Why Choose a Doctor’s Pregnancy Test? 

According to the National Women’s Health Information Center, the home pregnancy test claims that they are 99 percent accurate on the first day of a missed period are overstated. They may both fail for various reasons as well as be so faint that they are very difficult to read properly. They advise that if you need to know with certainty that you are pregnant at the earliest stages of pregnancy, it is well to opt for a test by your doctor to confirm your teen pregnancy.  


Related Article: Surviving an Unplanned Pregnancy >>