Home pregnancy tests offer a convenient way to detect pregnancy by identifying human chorionic gonadotropin (hCG), a hormone produced during pregnancy. These tests are widely available and provide a quick initial assessment. While generally accurate, sometimes the result is neither clearly positive nor negative. This unclear outcome is known as an inconclusive pregnancy test.
What Constitutes an Inconclusive Pregnancy Test?
An inconclusive pregnancy test result means the test did not provide a definitive positive or negative indication. For strip or stick tests, this can appear as an extremely faint, partial, or smudged line that is difficult to interpret. A test is also inconclusive if the control line, which confirms the test is working, does not appear. Digital pregnancy tests, which typically display “Pregnant” or “Not Pregnant,” might show an error message, a blank screen, or an “inconclusive” display.
Common Causes of Unclear Results
Testing too early is a common reason for unclear results. Home pregnancy tests detect hCG, which begins to accumulate in the body after a fertilized egg implants, typically six to ten days after conception. If a test is taken before hCG levels have risen sufficiently, it may produce a very faint line or a negative result. hCG levels typically double every two to three days in early pregnancy, making later testing more accurate.
Urine dilution can impact test accuracy. Drinking excessive fluids before testing can lower hCG concentration, potentially leading to an inconclusive or false-negative result, especially in early pregnancy. This effect is more pronounced with tests that have lower sensitivity to hCG. User error is another common factor; failing to follow package instructions precisely, such as not holding the test in the urine stream for the correct duration or reading results outside the recommended timeframe, can lead to invalid outcomes.
Faulty or expired tests can yield unreliable results. The chemical components, including antibodies that detect hCG, can degrade over time, making expired tests less effective. This degradation primarily increases the likelihood of a false negative, but can also lead to unpredictable results. Evaporation lines are faint, colorless streaks that appear as the urine dries, particularly if the test is read after the recommended window. These lines do not contain dye and are not indicative of pregnancy, but can be mistaken for a faint positive.
A chemical pregnancy, an early miscarriage occurring shortly after implantation, can also result in an inconclusive test. Here, hCG levels rise enough for an initial positive, then fall rapidly as the pregnancy does not progress. Certain medications, particularly fertility treatments containing hCG, can interfere with test results, leading to a false positive. Other medications, such as some anticonvulsants, can cause false negatives by affecting hormone levels.
Next Steps After an Inconclusive Test
After an inconclusive pregnancy test, retesting is advised. Waiting two to three days allows hCG levels to increase if a pregnancy is progressing, making detection easier. Retesting with a new kit also avoids issues with a previous faulty test. Using first morning urine is beneficial, as it is usually the most concentrated and contains the highest levels of hCG, especially in early pregnancy.
Carefully following the instructions provided with the new test kit is important for accurate results. Each brand may have slightly different procedures, including the duration for holding the test and the timeframe for reading. Adhering to these guidelines minimizes user error. Considering a different brand or type of test, such as a digital test, might provide clearer results, as digital tests display “Pregnant” or “Not Pregnant,” reducing ambiguity.
Consulting a healthcare professional is recommended if multiple inconclusive results occur or if there are concerns about potential complications. A medical provider can perform a blood test, which is more sensitive than a urine test and can detect lower levels of hCG earlier in pregnancy. They can also monitor hCG levels to determine if a pregnancy is progressing normally. Seeking medical advice is important if symptoms such as severe abdominal pain, unusual bleeding, or other concerning signs are present.