Blood tests to determine if you are pregnant are considered to be more reliable as compared to urine or home pregnancy tests. But don’t be so sure. They can sometimes go wrong. So they might show up as negative even though you may be pregnant or may show false positive results which means that you actually are not pregnant. Let’s look at what blood pregnancy tests are, how exactly they work, and what are the implications of the results.
Blood pregnancy tests measure the amount of a particular hormone, mainly, the human chorionic gonadotropin (HCG) present in the blood. The placenta of a pregnant woman produces this particular hormone. Blood and urine tests help detect the presence of this hormone within the first ten days of fertilization. Blood pregnancy tests are mainly of two types. The first helps measure the exact amount of human chorionic gonadotropin present in your blood, while the second is a simpler version which simply gives a positive or negative result. Blood tests help determine if you are pregnant much earlier than a home pregnancy test. It is therefore advisable to get a blood test done if you have some symptoms of pregnancy such as breast tenderness, pelvic pain, and delayed menstrual period.
Sometimes however we find that we get the wrong results with pregnancy tests. Even though you may be pregnant the test may not detect the chorionic gonadotropin (hCG). This generally happens when the test is done too early. You have to wait for at least a week after the fertilization period to get positive results.
Your results may be dependant a great deal on the lab where you have the test done, the methodology they use and the technique of the test as well. Most of these blood tests give you results that are approximately 97% accurate, provided they are done properly.
Sometimes your blood test may show up as negative even though you may have all the symptoms of pregnancy. This mostly happens when you are on some kind of diuretic medication or “fluid pills”. These drugs generally come in the way of your test result.
If you are experiencing all the symptoms of pregnancy and yet your blood tests show as negative don’t take a chance. Simply go ahead and repeat the test because your body could be trying to tell you something that the test does not. The test ultimately might turn out positive.
Submitted by M T on April 14, 2010 at 01:14