The diagnosis of pregnancy is a three-pronged approach using three main diagnostic tools. These are history and physical examination, laboratory evaluation, and ultrasonography. After the initial anticipation which takes you to your doctor, the doctor orders tests from the laboratory. There are certain markers secreted in your body that suggest pregnancy. Think of these as signals given out by your body. Human chorionic gonadotropin (HCG) is one such marker used extensively in the diagnosis of pregnancy. It was discovered in 1930. It is produced by the special cells of your fertilized eggs. While HCG is a reliable marker of pregnancy, it cannot be detected until after the foetus is firmly implanted in the uterus. This results in false negatives if the test is performed during the very early stages of pregnancy.
Laboratory tests include taking urine and blood samples. Such samples can be collected at any place and tested at a pathology lab. These days, convenient, easy to use home pregnancy kits are readily available in the market. Clear instructions given on the pack make it easy to use. The tests usually confirm if you are pregnant. A doctor however, can confirm it with more tests and examinations.
While blood tests take longer than the home tests to confirm pregnancy, they are more accurate.
There are two types of blood pregnancy tests available - qualitative and quantitative.
Blood test simply checks the level of HCG and gives clear results. HCG is detectable in the blood of approximately 5% of patients 8 days after conception and in more than 98% of patients after 11 days. The initial rate of rise, measured by serial quantitative HCG testing, is important in the monitoring of early complicated pregnancies.
Laboratory tests, pregnancy tests can also give wrong results, i.e. a false positive or a false negative. It is always best to be well informed. While urine tests can be performed at home, blood tests are done at labs. While both the tests confirm pregnancy, blood tests are generally more accurate. It has been documented that many users misunderstand or fail to follow the instructions in the home pregnancy test kits. Improper usage may cause both false negatives and false positives. So, the first move should be to follow the steps correctly.
Accuracy Of A Home Pregnancy Test
• How closely you follow instructions.
• When you ovulate in your cycle and how soon implantation occurs.
• How soon after pregnancy you take the test.
• The sensitivity of the pregnancy test.
False negative readings can occur when testing is done too early. Most doctors recommend that you wait until the first day of your missed period before taking a urine pregnancy test.This is usually about two weeks after conception.
False positive test results may occur due to incorrect application, use of certain drugs containing the HCG molecule, and non-pregnant production of the HCG molecule which occurs in some tumours. A woman who has been given an HCG injection due to infertility treatment will also test positive on pregnancy tests, regardless of her actual pregnancy status.
Close coordination with your doctor will help you sail effortlessly through these tests and help you enjoy your pregnancy.