When should I request a blood pregnancy test?

March 5, 2010

A blood pregnancy test is also referred to as a pregnancy serum test. It is used to detect pregnancy by measuring the amount of pregnancy hormone in the bloodstream. The pregnancy hormone is known as human chorionic gonadotropin or hCG. This hormone can be detected in the urine and bloodstream within a period of ten days after fertilization has occurred and is produced by the placenta. Blood pregnancy tests are of two types, a quantitative blood test which detects the exact quantity of the pregnancy hormone in the woman's bloodstream and a qualitative blood test which provides a yes or no answer to if the woman is pregnant.

Blood pregnancy tests are able to detect pregnancy even before a home pregnancy test. Detection through these tests is possible 7 to 12 days from the date of possible conception. They can also measure the amount of pregnancy hormone in the blood. This information is useful when certain problems related to pregnancy are being tracked by your doctor. If a woman is experiencing symptoms such as a delayed period, pain in the pelvic area, tenderness in the breasts, vomiting and spotting, a blood pregnancy test may be done to confirm if she is pregnant or not.

A normal pattern of human chorionic gonadotropin levels over a period of time is characteristic of a healthy pregnancy. The level of pregnancy hormone tends to rise during the first trimester of pregnancy and then slowly starts to decrease. In the first trimester, the blood pregnancy test may be done again and again to check if the hormone levels are rising normally. If this does not happen, there may be trouble with the pregnancy. After childbirth, the levels fall back to zero very quickly. This level will also decrease if miscarriage or abortion has taken place. Blood pregnancy tests are more accurate that home pregnancy tests. However, the results also largely depend on the laboratory and the method of performing the test. In some cases, the home pregnancy test may be positive, while the blood pregnancy test may turn out negative. This is because laboratories differ as to what constitutes a positive pregnancy test. Usually the cut off for positive results are 5, 10 and 25 units. Levels that fall before 5 are considered negative. In many cases false positive home pregnancy test results may also occur. Diuretic medications may sometimes interfere with the results of a qualitative blood pregnancy test. Therefore if a woman is taking such medication, she may obtain negative results even though she may be pregnant.

Submitted by M T on March 5, 2010 at 02:04

A pregnancy test is done to determine if a woman is pregnant. Firstly the process of pregnancy should be understood. At the start conception occurs when the sperm meets the egg and fertilizes the egg. After the sperm meets the egg it travels through the fallopian tube down to the uterus. Once it reaches the uterus it tries to cling onto the walls of the uterus by trying to implant itself. Only once the fertilization occurs after implantation then only does pregnancy occur. A pregnancy test looks for any chemical markers or any hormones that are associated with pregnancy. These chemical markers are found in the blood and the urine samples. One reliable marker for pregnancy is the human chorionic gonadotropin or the hCG which can only be detected after the implantation. It is known to be a hormone that is secreted by the developing placenta shortly after a fertilized egg has been implanted in the uterus.

Human chorionic gonadotropin is detectable in urine and blood within just ten days of fertilization. There are two kinds of blood pregnancy test namely quantitative blood test which measures the exact amount of hCG in the blood and the qualitative blood test which simply determines if a woman is pregnant or not. A blood pregnancy test can detect pregnancy about 7to 12 days after conception. It also helps to measure the amount of hCG in the blood. This is helpful to a doctor as it helps in tracking certain problems in pregnancy. If there are any symptoms of pregnancy like missed or delayed menstrual cycle, breast tenderness, pelvic pain or nausea a blood pregnancy test can be done to determine pregnancy. A blood pregnancy test is considered more reliable than a home urine test. Blood test measure smaller amounts of the hCG hormone and therefore can detect pregnancy earlier than a urine test.

A blood pregnancy test or an hCG test is measured in thousandths of International Units, or mIU. If a woman is pregnant then at ten days after ovulation the amount of hCG in her system should be around 25 mIU. At 12 days past ovulation it should be around 50 mIU and around 100 mIU at around two weeks after ovulation. Blood tests can be used to determine pregnancy at around 5mIU but this at times can present a false positive. Blood tests can determine pregnancy earlier than home pregnancy tests. A doctor should always be consulted to determine results of a blood pregnancy test.

Submitted by M T on February 25, 2010 at 01:09

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