A home pregnancy test helps a woman find out if she is pregnant. The test results from home pregnancy tests are private and they take but a few minutes. With the help of such early pregnancy tests, you can make an early diagnosis of your pregnancy and take appropriate care and caution. Early pregnancy tests are conducted at home or in the laboratory. They test for the presence of HCG (Human Chorionic Gonadotropin). This is the earliest test of pregnancy since this hormone can be detected in the woman's blood or urine even before she misses her menstrual period.
The HCG is produced by the placenta after the embryo gets attached to the uterine lining. Most normal pregnancies show a doubling of the HCG levels every 72 hours. This hormone peaks till about 8 - 10 weeks of pregnancy and then remains at a lower level for the remaining gestation period. Home pregnancy tests are available over-the-counter with easy to use instructions. Their accuracy is fairly high too.
The early pregnancy tests are carried out on the first urine in the morning, as it would contain sufficient HCG level. If this test is performed too early, it may give a false negative result. Once the embryo attaches itself to the uterine lining, HCG is produced in the placenta. HCG levels are measured in milliInternational Units (mIU). These units are equal to 1/1000th of an IU per milliliter. The sensitive early pregnancy tests can measure 25-50 mIU of hCG, which is seen around the 3rd or 5th week of pregnancy. There are pregnancy tests that are capable of detecting even lower levels but they may not be as accurate. Blood tests for pregnancy are more accurate than urine tests.
The home pregnancy tests are usually bought over-the-counter. Such a pregnancy test that can be conducted in the privacy of your home uses a urine sample. You must read the instructions carefully. Some home pregnancy tests are dip tests. You are required to collect the urine in a cup and dip the chemical stick into it. Some other types of home pregnancy tests involve putting urine into a special container with an eyedropper. Usually the results are seen in a few minutes. It may involve a change in color or a line of another color appearing on the dipstick. In some brands, a '+' sign appears in the result window. Some home pregnancy test kits are sensitive enough to pick up as little as 25 mIU/ml hormone levels. The standard sensitivity for most early pregnancy tests is about 300 mIU/ml.
HCG pregnancy test
HCG pregnancy tests can be easily conducted at home. These tests can be bought over-the- counter. The process of actually testing the urine varies between tests. Many home tests come with a stick that is dipped into the urine. The color code indicates the results of the test. The change of color is due to the fact that urine is mixed with monoclonal antibodies that are coated so as to get them to adhere to HCG if present. Some tests involve putting some of the urine into a special container with an eyedropper. If the process is not properly carried out, it may display inaccurate readings.
Pregnancy blood test
A blood test for pregnancy administered by a doctor is more sensitive than home pregnancy tests that are available. This blood pregnancy test is an early pregnancy test and will show accurate results even when taken 7 or 12 days after conception. A quantitative blood test is known as a beta HCG test. This blood pregnancy test is highly accurate as it is sensitive to very small amounts of HCG in the blood. A qualitative blood test for pregnancy is merely a confirmation or otherwise, similar to the urine test. Blood tests tend to pickup HCG levels earlier than home pregnancy tests.
Blood tests require medical assistance and can be relatively more expensive. Repeated blood tests can be helpful not only in detecting pregnancy but also if it is healthy or if there are complications such as multiple pregnancies or ectopic or molar pregnancy. Since blood pregnancy tests can determine the levels of HCG, they can help in dating the pregnancy and keeping a watchful eye on early pregnancy.
Home pregnancy test accuracy
The accuracy of the home pregnancy tests is nearly 97%. Though there is a variation between brands, most of the home pregnancy tests are sensitive enough to pick up traces of HCG. Sometimes the pregnancy test result is a false negative if there is not enough HCG in the urine to show a positive result. It is generally recommended to conduct the test again after 2 weeks. There are some medication and prescription drugs that can affect the accuracy of the home pregnancy tests. Drugs that contain the pregnancy hormone HCG can give a false positive pregnancy test result. Blood and urine tests performed at a laboratory are nearly 97% - 100% accurate in detecting pregnancy.
Use of antibiotics, prescription drugs, and birth control pills should not generally affect the accuracy of the pregnancy tests. Drugs containing HCG can give false positive results. It is interesting to note the evolution of the pregnancy tests. It was in the late 1920s that it was found that if you injected the urine of a pregnant woman into a rabbit, it would result in bulging masses on the ovaries of the rabbit. A level of 5 mIU is considered enough to confirm pregnancy. HCG levels keep doubling every two days during early pregnancy.