Home pregnancy tests offer a convenient way to check for pregnancy, but they can sometimes present confusing results. One common source of uncertainty is a faint mark often referred to as an “indent line.” Understanding the nature of these lines can help clarify test outcomes and reduce anxiety.
Visual Characteristics of an Indent Line
An indent line appears as a colorless groove or shadow where the test line would normally form. Pregnancy tests are manufactured with pre-set indentations for both the control and test lines, designed to fill with dye if human chorionic gonadotropin (hCG) is detected. A true positive line activates the dye, appearing in a distinct color like pink or blue, but an indent line lacks this coloration and may look translucent or gray.
The visibility of an indent line is influenced by lighting or viewing angle; it may only be noticeable when held to a light source or examined closely. In contrast, a genuine positive line, even if faint, displays color within the test’s 3 to 10-minute reading window. A true positive line is also consistent in width, unlike an indent line which may appear thinner or less defined.
Understanding Indent Line Causes and What to Do Next
Indent lines occur due to manufacturing factors. All test strips have pre-formed indentations, and sometimes, a small amount of dye can get trapped within the test line’s indent as urine moves across the strip. As the test dries and urine evaporates, this trapped dye becomes more visible, creating a line without indicating pregnancy. This differs from an evaporation line, which appears after the recommended reading time as the test dries completely.
If you observe an indent line, it is advisable to retest to confirm the result. When retesting, it is generally recommended to use a new test, potentially from a different brand, and to use your first morning urine, as it typically has the highest concentration of hCG if pregnancy is present. It is also important to carefully follow the instructions provided with the pregnancy test, paying close attention to the recommended reading window. If repeat tests continue to show unclear results or if you have concerns, consulting a healthcare professional for a blood test for hCG levels can provide a definitive answer.