If you think you’re pregnant, choosing the right pregnancy test for you can be confusing as there is such an array of different tests it can be difficult to decide which one to buy.
There are two main types of pregnancy tests:
Home Pregnancy Tests
These work by testing the urine for the presence of human chorionic gonadotropin (HCG). The woman either puts the test stick into her midstream flow of urine, or will dip the test stick into a clean container of urine.
After two or three minutes a result appears in the result windows. This is usually one blue or pink line in one window to show the test is working and one blue or pink line in another window to show pregnancy. If you are not pregnant, that window will be blank.
Some tests show the result as one line if you’re not pregnant and a cross shape if you are pregnant and some of the more modern tests are digital and the result window will say "Pregnant" or "Not Pregnant". Some digital tests are able to estimate how many weeks pregnant you are.
All of these tests are available over the counter or online, can be done at home and do not require a doctor’s prescription.
Blood Tests
Pregnancy can also be diagnosed by blood test but are performed less often than urine tests. Blood tests are frequently performed if the woman has had IVF, in order to see if the IVF cycle has worked.
Blood tests can also be done if pregnancy complications are suspected such as molar pregnancy, ectopic pregnancy and multiple gestation (e.g. twins or triplets).
You can, however, request a pregnancy blood test, although it will cost more than a home pregnancy urine test. The blood test has the advantage of being able to detect pregnancy as early as 10 days after conception. Blood pregnancy tests must be performed in a doctor's office or lab.
Which Type of Test is Best?
Of the two types of test, the blood test can detect pregnancy at an earlier stage and is more accurate than a home pregnancy test. However, there are cases where it has shown a false positive if the person has an underlying immune-deficiency.
If you’re anxious to know as soon as possible or there is a medical reason for having one, a blood test is by far the most superior test. The downsides are, you have to have it done by a doctor, it takes longer to discover the result and it is uncomfortable, particularly if you don’t like needles.
Home pregnancy urine tests are 97 percent accurate if used and interpreted correctly. False negatives can sometimes happen if the woman tests too early. If a test gives a negative result and the woman’s period does not occur and she experiences other pregnancy symptoms such as sore breasts and nausea, she should re-test a week or two later.
Some pregnancy tests boast being able to detect pregnancy before your period is even due, but these are only accurate around half the time, so it is usually better to wait until at least the day your period should have arrived.
Digital brands make it much easier for women to read the results and give you an indication of how far along you are, so they are among the best urine tests on the market, although they are the most expensive.
Tip: If you buy from an online pharmacy, rather than instore, you can often buy at wholesale price which will save you money.
Sources:
HCG blood test – quantitative, Medline Plus. Web. 23 April 2012. http://www.nlm.nih.gov/medlineplus/ency/article/003510.htm
Understanding Pregnancy Tests: Urine and Blood. American Pregnancy Association. Web. 23 April 2012. http://americanpregnancy.org/gettingpregnant/understandpregnancytests.html
Urine hCG Tests May Miss Early Pregnancy, Doctor’s Guide. Web. 23 April 2012. http://www.pslgroup.com/dg/209022.htm
Frequent false positive beta human chorionic gonadotropin tests in immunoglobulin A deficiency, Clin Exp Immunol. 2005 August; 141(2): 333–337. Full Text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1809437
Joanna is a freelance health writer for The Mother magazine and Suite 101 with a column on infertility, http://infertility.suite101.com/ She is the mother of five children and practices natural childbirth, delayed cord clamping, full term breastfeeding and organic food diet.
Reviewed April 23, 2012
by Michele Blacksberg RN
Edited by Jody Smith