Home Pregnancy-related Tests

If you find that your period is late, and have reason to suspect pregnancy, a home test can be a reliable method for you to find out. There are various self tests available over the counter. These tests are designed to detect the hormone Human Chorionic Gonadotropin (HCG).The results are rarely inaccurate. For the best results wait one week after your missed period and follow the instructions exactly.

Home Pregnancy & Fertility Tests

Why Test for Pregnancy at Home?

Discovering you may be pregnant is exciting. You may be anxious to get an answer.  Today home pregnancy tests can provide you with confirmation as early as 1 week after your missed period. So you don’t have to wait very long to get answers in the comfort of your home. A pregnancy blood test requires going to a physician, who then sends the sample to a lab, and results usually follow a few days later. For most women, a home pregnancy test kit is accessible, affordable and is the quickest way to determine if you are pregnant.

Types of Home Pregnancy Tests

Urine Pregnancy Test Kit

There are 2 main methods for the urine pregnancy test.

  1. Requires you to urinate on a test strip or dipstick. If you are pregnant, an area on the strip/stick will change color if it detects the presence of HCG
  2. Requires you to urinate into a collection cup and then place a few drops of urine into a test device. Some of these home pregnancy tests require that you dip the test device into the filled cup.

Both types of urine based home pregnancy tests work the same; they test for HCG to provide to provide results such as:

  • Pregnant/Not pregnant
  • Positive/Negative
  • +/-

Depending on the sensitivity of the home pregnancy test, the presence of HCG can be found in the urine from 1-7 days after your missed period. As a result, if given a negative result, it is suggested that the test be repeated.

A urine pregnancy test is approximately 99% accurate. However, for everywoman the level of accuracy may differ because:

  • Home pregnancy tests vary in precision when detecting HCG
  • Of the dynamic nature of ovulation and menstrual cycles
  • The exact date of conception is not always apparent

The benefits of a urine based home pregnancy test are:

  • You can take the test at home
  • Almost immediate results

The disadvantages of a urine based home pregnancy test are:

  • Can take up to a week before the presence of HCG is detectable in urine
  • Doesn’t tell you what how many weeks the embryo is
  • May yield in accurate results if you do not careful to follow instructions

Costs:

A self test pregnancy kit can range in the USA from $7.99 to $19.99, and in the UK from £5 to £15.

Home Pregnancy Test and the False Negative

During the first few weeks of pregnancy the amount of HCG present in your body increases. Self tests are designed to detect this hormone from urine. The presence of HCG is more prominent in blood then urine in the first few days of pregnancy. As a result, early testing could give a false negative, because the HCG is not yet detected in the urine. This is why it is suggested that the test be taken and repeated a week later if given a negative result.

HCG has a stronger presence in the blood stream than urine in the first week of pregnancy. For this reason a blood test is often recommend to confirm the home pregnancy test results.

Other reasons for a false negative are:

  • Incorrect Testing. This could be the result of misreading the instructions, waiting too long to read the results, or not waiting long enough. It is important to strictly follow the instructions for your home pregnancy test.
  • Diluted Urine. To avoid a false negative from diluted urine, it is best to take the test when you first wake up in the morning.

False Positive with a Home Pregnancy Test

A false positive does not occur often. However there have been a few cases with false positive results. Causes of a false positive pregnancy result include:

  • Blood or Protein. If the urine sample contains blood or protein, the test can be skewed and result in a false positive.
  • Prescribed Drugs. Certain drugs can cause a false positive. Some examples include: Diuretics, Promethazine (antihistamine).
  • Faulty Pregnancy Test Kit. An old, expired or damaged kit can cause a false positive.

History of Home Pregnancy Test Kits

The first home pregnancy kit was created in 1976. Warner-Chilcott developed e.p.t  “Early Pregnancy Test” and was seeking the FDA’s approval. Following e.p.t, were 3 other self-test kits: Predictor, ACU-TEST, and Answer.  At the end of 1977 these kits met the FDA requirements and put onto the market.

At this time the tests were more complex, required multiple steps and took 2 hours to receive the results. The accuracy of the results depended on the nature:

  • Positive was 97% certain.
  • Negative was 80% certain.

The tests evolved to:

  • Provide more accurate results
  • Shorter wait times
  • Earlier detection

FDA Approval

Today, you will find the FDA approval on a majority of branded home pregnancy test kits. The purpose is to provide a quality guarantee. The self-test pregnancy kits have been designed to meet FDA standards, and are tested to perform as advertised.  This is necessary because it provides you with confidence that, if you complete the test as instructed, you will receive accurate results.

More Information about Home Pregnancy Tests:

Mayo Clinic Article: Home pregnancy tests: Can you trust the results?

Find information about home pregnancy tests and their level of accuracy.

American Pregnancy Association: Understanding Pregnancy Tests: Urine & Blood

Article provides information about urine tests and blood tests to determine pregnancy includes FAQ section.

SoFeminine.co.uk: Pregnancy Tests

This article reviews the various pregnancy tests available, when to take the test and more.

WebMD: Home Pregnancy Tests

Learn more about the types of home pregnancy tests and their accuracy.

About.com: Home Pregnancy Tests

Compares and reviews different home pregnancy tests for accuracy and sensitivity to HCG.

National Institute of History (NIH): The History of the Pregnancy Test

Article provides a timeline of pregnancy testing from Ancient Egypt to modern days.