This is a frequently asked question. Quite often, this doubt occurs when the home pregnancy test (HPT) taken results in a faint line that indicates it is positive, meaning that you are pregnant. However, if the line indicating the test is positive is faint, it could mean that your human chrionic gonadotropin (hCG) levels are not high enough.
An HPT is a urine test and is the most common method of detecting pregnancy. What the urine test does is that it determines the level of hCG because this hormone is only produced in a woman's body when she is pregnant. Basically, this hormone is secreted into the bloodstream when a fertilized egg is planted into the uterus. HCG is measured in mIU/ml, i.e., milli international units per milliliter, of urine.
Once the egg is implanted, the hCG levels in your urine will start increasing steadily post ovulation. Usually, if a woman is pregnant her hCG levels will be around 25 mIU/ml in ten days post ovulation (dpo). In a fortnight, the hCG count usually multiplies and should be around 100 mIU/ml. These are average levels and the actual figures would differ from woman to woman.
Since the hCG levels multiply, it means that you can take a pregnancy test within a couple of days of missing your period to confirm whether or not you are pregnant. When taking the test, check the back of the HPT kit for sensitivity. Most test kits come with a sensitivity of 50 mIU/ml, and there are a few available with a sensitivity as low as 20 mIU/ml.
The ideal time to take a pregnancy test is ten days after you miss your period. In such time, the hCG levels would have increased enough to show a distinctive line indicating that you are pregnant. Take a pregnancy test in the morning, as the hCG concentration is highest at that time. Also, if the line is faint, repeat the test the next morning. If the line remains faint, you will need to take a blood test. If you have taken the test twice with the same result, try a different brand of HPT. Sometimes, the kit could be faulty or the line could be faint as a result of urine dilution.
Most often in early pregnancies, as early as four to six weeks, the blood test might return as borderline. This could be, because your hCG levels are not at the expected level. There is no need to panic though, in such a scenario, you will have to be patient and repeat the blood test in a couple of weeks. If it has been over six weeks, your tests are positive, and the second blood test is also inconclusive, then at eight weeks you can conduct an ultrasound to confirm pregnancy. If however, even the ultrasound cannot detect anything, it implies that you were pregnant, but you have miscarried. However, the pregnant tissues remain in the body causing a positive urine test and a borderline blood test.
You can also confirm whether you are pregnant by taking two blood tests within 48 hours. This is also referred to as a beta hCG test wherein the doctor will check if the hCG levels are doubling (as they should). If they are, it means that you are pregnant. If, however, the hCG levels have dropped or halved in 48 hours, it indicates that you have miscarried, and if both blood tests show a value less than 5, it means that you were never pregnant and the HPT were false positives.
Submitted by M T on March 5, 2010 at 02:15