Home pregnancy tests and blood pregnancy tests taken at a doctor's office measure the presence of the hCG, a hormone secreted by the developing placenta shortly after fertilization. According to WomensHealth.gov, home pregnancy tests are highly accurate when used correctly and blood tests are even more so 1. There are a handful of factors, though, that can lead to pregnancy test errors. An understanding of these can help you understand what not to do when administering a test.
Failure to Follow Instructions
Whether you purchase a kit that requires you to dip a stick in urine or one that requires a steady urine stream to saturate it, precision is key. If liquid inadvertently comes in contact with the area where results are read, it can cause an error. Avoid this mistake by holding the test window away from your urine stream, or by dipping your stick only to the point indicated on the directions. Be also mindful to read the results of a home pregnancy within the alloted reaction time—usually a few minutes. Tests read after the reaction time, or tests used after the expiration date, can be incorrect. Read directions thoroughly prior to beginning a test, and follow the directions to the T until results have been read.
- Whether you purchase a kit that requires you to dip a stick in urine or one that requires a steady urine stream to saturate it, precision is key.
- Avoid this mistake by holding the test window away from your urine stream, or by dipping your stick only to the point indicated on the directions.
Diet Pills and Home Pregnancy Test
Urine that has been diluted by liquids can give a false negative when using home pregnancy results. Avoid this error by administering your test first thing in the morning prior to urinating, and remember not to drink lots of water before sleeping or during the night. If you can't wait until morning, at least hold your urine for an hour or two before testing.
- Urine that has been diluted by liquids can give a false negative when using home pregnancy results.
- If you can't wait until morning, at least hold your urine for an hour or two before testing.
Other Reasons for False Readings
Medications used to treat infertility or perphenazine used to treat severe emotional and mental disorders, can give false results. In addition, certain forms of uterine, breast and ovarian cancer can elevate hCG levels and lead to a false positive test.
Diet Pills and Home Pregnancy Test
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- Babyhopes.com: How Accurate Are Home Pregnancy Tests?
- Justmommies.com: False Positive Pregnancy Test
- Mentalhealth.com: Perphenazine
- Tamez-Pérez HE, Quintanilla-Flores DL, Rodríguez-Gutiérrez R, González-González JG, Tamez-Peña AL. Steroid hyperglycemia: Prevalence, early detection and therapeutic recommendations: A narrative review. World J Diabetes. 2015;6(8):1073–1081. doi:10.4239/wjd.v6.i8.1073
- Bradley SH, Abraham S, Callister ME, et al. Sensitivity of chest X-ray for detecting lung cancer in people presenting with symptoms: a systematic review. Br J Gen Pract. 2019. doi:10.3399/bjgp19X706853
- Azizi G, Keller JM, Lewis M, et al. Association of Hashimoto's thyroiditis with thyroid cancer. Endocr Relat Cancer. 2014;21(6):845–852. doi:10.1530/ERC-14-0258
- Cobos B, Haskard-Zolnierek K, Howard K. White coat hypertension: improving the patient-health care practitioner relationship. Psychol Res Behav Manag. 2015;8:133–141. doi:10.2147/PRBM.S61192
- National Institute of Diabetes and Digestive Kidney Diseases. Diabetes tests & diagnosis. Updated December 2016.
- American Cancer Society. Limitations of mammograms. Updated October 3, 2019.
- Boyd C, Wood K, Whitaker D. Accuracy in 24-hour urine collection at a tertiary center. Rev Urol. 2018;20(3):119-24. doi:10.3909/riu0807
- Hancock GE, Hepworth T, Wembridge K. Accuracy and reliability of knee goniometry methods. J Exp Orthop. 2018;5(1):46. doi:10.1186/s40634-018-0161-5
Based in Charlotte, N.C., Virginia Franco has more than 15 years experience freelance writing. Her work has appeared in various print and online publications, including the education magazine "My School Rocks" and Work.com. Franco has a master's degree in social work with an emphasis in health care from the University of Maryland and a journalism degree from the University of Richmond.