Home pregnancy tests
These tests can be very useful because they can tell you if you’re pregnant in just minutes, with a urine sample taken any time of the day, fewer than two weeks after conception. Home pregnancy tests involve placing urine on a prepared chemical strip and waiting for one or two minutes for the strip to show the result. These tests check for a hormone that is produced in excess amounts during pregnancy known as human chorionic gonadotropin or hCG. hCG levels are normally low in non-pregnant woman. However, with pregnancy, your placenta produces large amounts of the hormone, causing higher amounts of hCG to be secreted in your urine.
Since hCG levels do not rise immediately, depending on how early you are in your pregnancy, a home pregnancy test can show a negative result even though you may actually be pregnant. Ideally, a home pregnancy test should be performed seven to ten days after missing your period in order to ensure a minimal amounts of false negative tests. Also it is important that you follow all the instructions correctly. If you had a negative test but tested yourself less than ten days after the first missed period, wait a few more days and try the test again. When done correctly, home pregnancy tests can be as accurate as urine tests done in a doctor’s office or laboratory.
Advantages of Home Pregnancy Tests:
Here are some of the advantages of home pregnancy tests:
- Home pregnancy tests are private
- Their results are virtually immediate
- Provide a very accurate diagnosis and early in pregnancy
- Can give you the opportunity to start taking good care of yourself during the first days of conception
Disadvantages of Home Pregnancy Tests:
Here are some of the drawbacks of home pregnancy tests:
- They can be somewhat pricey. Also, since you’re less likely to be confident in the results of the tests, you may be more apt to try and get a retest, thereby increasing the cost to you even more.
- If a test produces a false negative result (a negative result when you are actually pregnant), you may put off seeing a physician and taking the appropriate steps to take care of yourself.
When to Take a Pregnancy Test and Other Tips
Here are some tips to ensure that your home pregnancy test is as accurate as possible:
- Be sure to read the directions for the test completely before using it to make sure that you are using it correctly.
- if you are not using first morning urine, make sure that your urine has been in your bladder for four hours
- It is best to have a watch or an easy to read clock close by to that you can time the length of the test correctly. If you end up reading the test too early, or too late, you may end up skewing the results.
- if you are on any type of medication (e.g. fertility drug), read the package inserts before testing to see if your medications will affect the results.
- Make sure that all the equipment in the test are clean and never reuse them.
- Do not drink excessive amounts of water in order to increase the volume of urine as this can dilute the concentration of hCG and give a false negative result (i.e. negative test result when you are actually pregnant).
- While you are waiting, it is best to place the sample on a flat surface where it won’t be disturbed or come into contact with extreme heat or cold.
- If you are performing a retest to confirm the results, it is best to wait a few days before trying the second test.
- Remember, home pregnancy tests are not designed to take the place of an examination by a doctor. You should always have a positive test confirmed by a physical exam and then proceed to a prenatal appointment.
Blood Pregnancy Test
An even more sensitive test can be performed by your doctor who can test the hCG levels in your blood. This test can detect pregnancy with virtually 100 percent accuracy as early as one week after conception, using just a few drops of blood. This test involves drawing blood from your arm and is more accurate than conventional home pregnancy tests because it can detect lower levels of hCG. A benefit of this test is that it can also be used to date the pregnancy by measuring the exact amount of hCG in the blood. hCG levels change predictably as pregnancy progresses, so hCG levels can be used to date the time of conception and determine the estimated date of birth. If your home pregnancy test is positive, be sure to make an appointment with your doctor right away who will be able to verify your pregnancy and begin your prenatal care.
Revision date: July 7, 2011
Last revised: by Janet A. Staessen, MD, PhD