Pregnancy Tests

Human chorionic gonadotropin, or hCG, is a protein hormone produced by the placenta.

Unrine-based pregnancy tests analyze the presence of hCG. The appearance and increased levels of hCG provide an excellent indicator of pregnancy. hCG is released into the mother’s circulation almost immediately after implantation (5 – 8 days after conception). hCG is produced in minute amounts and then, rising exponentially, the concentration doubles approximately every 2.2 days.

This means that in a normal pregnancy, hCG doubles every 2.2 days. Because of this, testing very early in the pregnancy can give a negative result. Yet 2 days later, because the hCG level has doubled, testing can register positive.

mIU/ml is the unit of measure for hCG. It stands for mili International Units of hCG per milliliter of urine. Simply put, it is a measure of the concentration of hCG in the client’s urine.

No. There are many types of tests on the market for both professional and home use. They have different sensitivity levels for detecting hCG. Some over-the-counter home tests only detect 150-250mIU’s of hCG. This means they may not pick up the pregnancy until well after the first missed period. The Precious Feet Pregnancy test, one of the most sensitive urine-based tests available, detects concentrations as low as 20 mLU/ml

No. The production of hCG can vary greatly from women to women in any given week of pregnancy with as much as a 20-fold variation in individual levels. Some women with high hCG may come up positive on the test very early, while others with low hCG may not show up until after the first missed period. In a recent study, reported in the Journal of American Medical Association, 10% of 250 women tested had not even implanted by the first missed period. Therefore, their hCG was so low that no urine test could detect it.

Because our test is so sensitive, it may pick up a positive result as early as 7 – 10 days post conception (21 to 24 days after the first day of the last period) depending on when implantation occurs and the client’s personal hCG levels. If hCG is detected at this early stage, the test line would be expected to be light as hCG levels are just beginning to build. However, when testing this early, the results should be verified after the first missed period. This is because, although the test picks up the presence of hCG, it does not guarantee a viable pregnancy. hCG may also be produced by an EPL or “early pregnancy loss”. This is an embryo which fails to implant properly in the uterus, or is rejected by the uterus. It is followed by a normal or slightly heavier than normal menstrual period, which may be 2 to 3 days late. hCG levels may rise in the week following implantation (second week of conception) like a normal-term pregnancy. When EPL occurs, hCG concentration in the urine reaches a peak 2 weeks after conception then rapidly declines.

Most women are unaware that they have had an EPL. EPL’s are much more common than people realize. Some reports indicate that EPL’s may occur in 31% of pregnancies overall. CPC lay counselors need to be aware that women may get a positive result from a test taken before the first missed period. However, the fertilized egg may not implant correctly, or the uterus may reject the embryo. An EPL can delay menses up to three days which would further lead the client to believe she is pregnant, while in reality that is no longer the case.

Yes it can. This happened to a woman at one center. A young woman took home a pregnancy test a few days before she missed her period and it was positive. She then came to the center a week later and was sure she was pregnant her period still had not started. But the center’s test come back negative. By the time she came to the center she had experienced an Early Pregnancy Loss. Her hCG had dropped to undetectable levels. The woman was urged to get a blood test, which verified the center’s results. It is good to understand this issue as you may have a similar case occur.

Yes. If you test earlier than 31 days, you should know that even if it is negative, a test should be given at 31 days to verify the results if your menses has not started. This is because your hCG level may have been too low to register on the first test. Or, if it reads positive, you should be advised that there is still a chance of Early Pregnancy Loss. It is our recommendation, and that of the leading hCG researcher, Dr. Laurence Cole of the University of New Mexico, that any test that indicates possible pregnancy before 31 days after the start of the last menses should be repeated on or after the 31st day. This assures accurate detection of a viable pregnancy.

Yes. Another factor is how diluted the urine is at the time of the test. The more concentrated the urine, the greater the concentration of the hCG. Remember, woman’s levels of hCG can vary markedly. If a woman who has low levels of hCG takes a pregnancy test early in her pregnancy using her first morning urine, it may come out positive because of higher concentrations of hCG. If she then goes to a center later in the day after consuming liquids, her urine will be very diluted and there may not be a high enough level of hCG to detect. If there is a question about the test results, confirm results by retesting using a first morning sample.

Yes. In fact, when results vary or are questionable, you should be retested with the first morning urine. If this is not possible, you need to limit liquid intake and go as long as possible without urinating before you come in. Remember, the more concentrated the urine is, the more concentrated the hCG will be. In such cases it may also be a good idea to wait 48 hours before retesting so that the hCG level can double to a more detectable level.

There are some medical conditions that will skew the test results. They are complicated and uncommon. If you test negative after 31 days and your period does not start, you should be encouraged to see your doctor. He will be able to order a blood test that will determine if hCG is present and if there are any medical concerns. If you test positive as the result of a medical condition, the doctor will be able to advise you on further medical care.

When conducing pregnancy testing it is important to remember that a center is relying on your self reporting about the last menses, the regularity or irregularity of your menstrual cycles, and your sexual activity.

To use the test, place it on a level, dry surface and put on protective gloves. Then take the dropper from the package and squeeze the bulb at the top of the dropper to remove the air.

Place the tip of the dropper in the urine and release the bulb while holding the dropper upright. While continuing to hold the dropper upright, squeeze the bulb to release four drops of urine in close succession into the sample well. After the urine has moved across the testing window, set your timer for five minutes and wait for the results.

Do not immediately dispose of the urine in case there is any need to redo the test. Within four minutes the control line “C” will begin to turn pink.

If the test is positive, another pink line will appear under the “T” or Test zone. If the test is negative, the zone under the “T” will not change color. The test line may show a variety of shades of pink from light to bright depending on the levels of hCG. If any shade of pink appears, even a very slight line, the test should be considered positive. If no pink line occurs in the control zone “C” the test is invalid.

High sensitivity urine-based pregnancy tests performed on specimens containing levels of hCG below 20 mIU may show color development over time, indicating the need to restest in 48 hours. Do not read the test after 10 minutes.