What would cause a false positive pregnancy blood test

False Positive on a Pregnancy Test

A false positive pregnancy test is a disappointment if you’re trying to get pregnant. On the other hand, it can create stress or fear if you’re not ready for a baby. There are a few factors that can interfere with the accuracy of the test and cause false positive results, although not as frequently as false negatives.

What a False Positive Test Means

A false positive urine or blood pregnancy test means you get a positive result when you are, in fact, not pregnant. Manufacturers say urine home pregnancy tests (HPTs) are 99 percent accurate to detect human chorionic gonadotropin (HCG) if done right, according to the Cleveland Clinic. Blood pregnancy tests have a similar accuracy.

Despite the accuracy of the test with perfect use, however, the results might be inaccurate and not reflect your true situation. Urine HPTs are more likely to give false results than a urine test done in a doctor’s office or a lab blood test. Blood pregnancy tests are the most sensitive because they pick up lower HCG levels than HPTs.

Reasons for a False Positive Pregnancy Test

Reasons for a false positive pregnancy test result range from a defective urine HPT test kit to factors in your blood or urine that can interfere with your test results. This can lead to can sometimes lead to an involved evaluation and unnecessary treatment.

Defective Test Kit

Your false positive pregnancy test result might be because the test did not work the way it should. The problem might have to do with how the test was constructed or a problem with the test antibodies that pick up HCG in urine or blood. The test should be repeated with a different brand as a check on the first test.

Impurities in the Urine Sample

Impurities, such as soap or detergent residue, in your urine sample can cause a false positive pregnancy test. This can happen if you collected your urine in a cup that was not clean or that you washed with soap or detergent. Repeat the test if you think this was the problem.

You should not have a problem with impurities with the brands that provide a clean cup in the packaged test kit. With some brands, you urinate on the test stick instead of collecting a sample in a cup.

Inaccurate Interpretation of Results

Make sure you follow all the instructions that come with your urine test kit. This includes accurate reading of the test result within the suggested time frame. If you wait too long to read your test, you might get a faint, so-called evaporation line which you might misinterpret as a positive result. You might also get a false positive result of your test kit is expired.

Antibodies in the Blood

Antibodies in your blood can cause a false positive pregnancy test result, according to the American College of Obstetricians and Gynecologists. Most pregnancy tests use antibodies as the test agent to bind to the HCG in your blood or urine. This results in a positive reading if HCG is present, and a negative result if is not. Nevertheless, certain antibodies in the blood can bind to the test antibodies and mimic a positive blood test result.

Blood Cells in the Urine

Red or white blood in the urine, due to kidney disease or a bladder infection, can also cause a positive result. A 2012 article in Annals of Laboratory Medicine illustrate the possibility of false positive urine pregnancy test if there are of white blood cells in the urine.

Prescription Drugs

Certain prescription drugs can cause a false positive pregnancy test result. Lab Tests Online lists the following:

  • Anticonvulsants used to treat seizures
  • Anti-Parkinsons medicines
  • Certain tranquilizers such as Valium

HCG-Producing Tumors

It is possible the HCG in your positive test is the result of a tumor instead of a pregnancy. These include:

  • Rare HCG-producing germ cell tumors, which arise from eggs in the ovaries and might not be diagnosed until they are advanced. Your abdomen might get bigger, making you think you are pregnant.
  • Also uncommon, gestational trophoblastic disease of the uterus is formed from abnormal growth of early embryonic cells. They can cause early pregnancy symptoms, such as morning sickness and an enlarging abdomen
  • Certain types of lung cancer may cause false results.
  • Benign ovarian cysts may also cause elevated HCG.

In all of these cases, a complete evaluation can determine the cause of your elevated HCG.

A Recent Miscarriage or Abortion

If you have reason to do a urine or blood pregnancy test soon after a miscarriage or a therapeutic abortion, you might get a positive result. This might lead you to wonder if you have a false positive result, if you are still pregnant, or if you have a new pregnancy.

Your pregnancy test can remain positive for up to five to six weeks after a miscarriage or an abortion. If you test within this time frame, you might get a positive result when in fact, you are not pregnant. In this situation, consult with your doctor for the appropriate evaluation, especially if you have pelvic pain or heavy or prolonged bleeding.


Pseudocyesis is a condition where some women are convinced they are pregnant when they are not. In some cases, a pregnancy test gives a false positive result. Some of these women even have pregnancy symptoms including morning sickness, fetal movement, and pseudo labor pains. An ultrasound exam is an important part of the evaluation.


The pituitary gland can secrete a small amount of HCG. This can increase as a woman ages, according to a study in published 2005 in Clinical Chemistry. If you are perimenopausal and get a pregnancy test done, for example to evaluate irregular periods, you might get a falsely positive urine or blood test result.

Clarify Your Situation

A pregnancy test result can cause joy or anxiety depending on your circumstances. If you think your HPT result is false positive, you can double-check it for accuracy by repeating the test. Whether you have a false positive on a urine test or a blood test, having your doctor evaluate your result and your health is important to clarify your situation.

7 Causes for a False Positive Pregnancy Test

Home pregnancy tests are a common tool used to find out if you’re expecting. Most at-home pregnancy tests are dip sticks, which are placed into the urine stream. The stick is then able to detect human chorionic gonadotropin (hCG), a hormone produced during early pregnancy.

Some pregnancy tests detect hCG very early in pregnancy. Reputable home pregnancy tests can be highly accurate, but they aren’t foolproof. False positives and negatives can occur for a variety of reasons. It’s also important to remember that once you have a positive pregnancy test, see your doctor to begin early prenatal care.

Read on to learn more about false positives on home pregnancy tests.

It’s possible to have a positive pregnancy test even if you aren’t technically pregnant. This is called a false positive, and is sometimes caused by a chemical pregnancy. A chemical pregnancy occurs if a fertilized egg, known as the embryo, is unable to implant, or grow, very early on. This can happen for a wide range of reasons.

Early pregnancy loss doesn’t occur because of anything the woman has done. It may be the result of issues within the uterus, such as fibroids, scar tissue, or a congenital uterine anomaly which causes the uterus to have an irregular shape.

Low amounts of certain hormones, such as progesterone, can reduce the likelihood of implantation and embryo growth.

Some causes of chemical pregnancy are unknown.

Chemical pregnancies are thought to be very common, but they typically go undetected if a pregnancy test is not taken. These early test results, when wrong, can be emotionally draining. For that reason, it is recommended that you wait to use an at-home pregnancy test until one week after you expected your period to start.

Sometimes a fertilized egg can implant itself outside of the main cavity of the uterus. This causes an ectopic pregnancy to occur. Ectopic pregnancies usually happen if a fertilized egg gets stuck in a fallopian tube during its journey to the uterus. This can happen if the tube has scar tissue, inflammation, is misshapen, or if there is a history of past uterine infections. This type of ectopic pregnancy is also known as a tubal pregnancy.

Ectopic pregnancies can also occur in the cervix, ovary, or abdominal cavity. An ectopic pregnancy cannot continue to become a normal pregnancy. The embryo is not viable because there’s no place for it to grow or thrive outside of the uterus.

The embryo will still produce hCG, even though it has implanted in the wrong place. That can cause a false-positive reading on an at-home pregnancy test.

Ectopic pregnancies are medical emergencies. Ectopic pregnancies can be damaging to the woman if left untreated, causing extreme blood loss or loss of the reproductive organs. Symptoms of ectopic pregnancy include:

  • nausea and sore breasts, which are also symptoms of a normal pregnancy
  • sharp waves of pain in the abdomen, pelvis, shoulder, or neck
  • severe pain on one side of the abdomen
  • light to heavy vaginal spotting or bleeding
  • dizziness or fainting
  • pressure on your rectum

Seek immediate medical help if you suspect an ectopic pregnancy.

You may continue to test positive for pregnancy following the loss of a pregnancy, either through miscarriage or abortion. During pregnancy, hCG levels continue to rise as the placenta grows, doubling every few days and peaking at around 10 weeks. When a pregnancy ends, hCG levels begin to recede, but it’s a slow process. The hormone can remain in your blood and urine for up to six weeks following the loss of your pregnancy. It’s possible to have a false-positive test until your hCG levels return to their prepregnancy state.

If the miscarriage was spontaneous, it’s also possible that not all of the pregnancy-related tissue was eliminated. This will cause hCG levels to remain elevated. When this occurs, a minor surgical procedure called a dilation and curettage is often required to remove the tissue.

Like most things in life, at-home pregnancy tests aren’t foolproof. It’s important to follow package directions exactly and to check the expiration date prior to use. Even with these safeguards, user error can occur. One of the most common mistakes is taking the test too early during your cycle. This can cause either a false negative or a false positive.

It’s also important to use the test when your urine is not diluted excessively with water and is very concentrated, such as when you first wake up in the morning.

Leaving the dipstick in your urine stream for the exact amount of time allotted is also important. Considering setting a timer on a stopwatch or your phone. That can help you track how long the dipstick has been in your urine stream. You’ll want to use a timer again while you wait for your results. Checking your results during the result time frame is also important.

Sometimes an evaporation line can be mistaken for a positive pregnancy test. Some at-home tests show two lines when hCG is detected and one line when hCG is not detected. The lines are usually a bright color, such as pink, red, or blue. Sometimes, a faint-colored second line will appear. This line may represent an early pregnancy or it may be an evaporation line. It’s probably an evaporation line if the line is completely colorless.

Evaporation lines may show up on a test you view after your urine has evaporated completely. Sometimes they’re caused by hormonal levels which don’t represent pregnancy. The best way to avoid being confused by an evaporation line is to follow the test’s timing directions exactly as they are given.

If you’re trying to become pregnant under a doctor’s care, you may be taking fertility medications. One of these is the synthetic hCG trigger shot, sold under the brand names Novarel, Pregnyl, Ovidrel, and Profasi. The hCG shot helps follicles release mature eggs. It may cause a false-positive reading on an at-home pregnancy test, particularly if the test is taken too early.

Other medications can also cause false-positive pregnancy tests. They include but are not limited to:

  • antianxiety medications, like diazepam (Valium) or alprazolam (Xanax)
  • antipsychotics, such as clozapine or chlorpromazine
  • anticonvulsants, like phenobarbital or other barbiturates
  • Parkinson’s disease medications, including bromocriptine (Parlodel)
  • diuretics, like furosemide (Lasix, Diuscreen)
  • antihistamines, including promethazine
  • methadone (Dolophine)

Rarely, certain medical conditions can cause a home pregnancy test to give a false positive. These include:

  • a urinary tract infection
  • kidney disease that causes blood or white blood cells in the urine
  • ovarian cysts, particularly corpus luteum cysts
  • more serious diseases such as ovarian cancer
  • pituitary problems (very rarely)

A positive at-home pregnancy test result should always be followed up with a doctor’s appointment. Your doctor may give you a urine or blood test to confirm the results and monitor your hCG levels. You may also get a transvaginal ultrasound to look for the gestational sac as confirmation that the pregnancy is proceeding normally.

If you have received a false positive, your doctor’s visit will determine that. It might be an incredible relief to find out you are not pregnant. But if you were excited by your early results, it can be very upsetting. It’s important to remember that false positives do happen and are not an indication that you will never get pregnant.

If you’ve been trying unsuccessfully to get pregnant for some time, particularly if you are over the age of 35, consider working with an infertility specialist. There are also support groups where you can find inspiration and obtain knowledge from women who have been through the same thing. Working one-on-one with a therapist, clergy member, family member, or trusted friend can also be beneficial.

Online pharmacy – determus.com

Online pharmacy – determus.com


Valium false positive pregnancy test

5 Jun 2012. Substances that cause false positive drug test results thc – substances or conditions. Diazepam tests positive for pcp as well as the ingredient in some cough medicines, dextromethorophan. So I took two pregnancy testst? Could taking valium cause a false positive on a home pregnancy test?” Thanks for contacting HCM Valium will not cause a false positive urine pregnancy test Hope this answers your question. Can i take lexapro and tramadol 29 Oct 2012. When trying to get pregnant, a false positive prgnancy test can be incredibly. benzodiazepines (Diazepam or Valium, Alprazolam or Xanax), . List of drugs that cause false positives on drug tests with reference sources and feedback. false positive for Opiates (Also false for pregnancy) (References: 32, and 36). Diazepam (generic name for Valium) – contains benzodiazepines .

  • A false positive pregnancy test can mean several things. Unfortunately, it’s often very difficult to know whether or not you are experiencing a false positive pregnancy test result. If you’ve been trying and you see a positive result, you think you are pregnant.
  • A false positive test result—a positive human chorionic gonadotropin (hCG) test result when you are not pregnant—can occur for a variety of reasons. Most over-the-counter pregnancy tests measure the levels of hCG in a woman’s urine.
  • Medications That Cause False Positive. Pregnancy Symptoms but tests negative. For the months of June, July, and August they have came at the same time When trying to get pregnant, a false positive prgnancy test can be incredibly disheartening.

    2 Feb 2011. I was due to have surgery that would have enabled me to be pain free & move on with my life, but due to this false positive test, it was cancelleded.

  • Can I Take Valium With Percocet Valium Xanax Vs Ivf Transfer Valium How Much Valium Autoinjector Suppliers. Taking valium during pregnancy. Valium and laughing gas togethe reffects. Valium cause depression. 2012 – повідомлень: 21 – авторів: 1 10 Soma band st. louis May also cause false positive pregnancy test. Diazepam (Diazemuls, Stesolid, Valclair, Valium) – false positive for PCP (Reference: 29). Diazepam (generic name for Valium) – contains benzodiazepines (Reference: 18, 20, 26). Conditions, pregnancy status and genetic predispositions. Antibiotics – False positives on Heroin Tests, Asthma medications (Marax, Bronkaid tablets, Primatine. (generic name for valium), Diazeparn False positives for PCP, Didrex , Dilantin, .

    False Positive Pregnancy Test

    Although it’s rare, a false positive pregnancy test result can happen. For some women, this result can be disappointing, especially if they were hoping to become pregnant. A false positive test result—a positive human chorionic gonadotropin (hCG) test result when you are not pregnant—can occur for a variety of reasons.

    Most over-the-counter pregnancy tests measure the levels of hCG in a woman’s urine. A urine pregnancy test is usually only positive in a woman who is pregnant and producing enough hCG to be detected by the test. A quantitative hCG test, which detects the level of hCG in the blood, can determine the exact age of the fetus and diagnose abnormal pregnancies. Blood tests can detect hCG at lower levels than urine tests, and therefore can detect a pregnancy earlier.

    Of course, it is possible for a woman to become pregnant, get a positive test result, and then miscarry. This is known as a chemical pregnancy. A positive hCG test result does not necessarily indicate a viable pregnancy. If an at-home pregnancy test shows a positive result, it is important to have a healthcare professional confirm the result with a blood test; after that, it is important that you continue to see your healthcare practitioner on a regular basis so that he or she can help you maximize your chances of maintaining a healthy pregnancy.

    Causes of a False Positive Pregnancy Test

    There are many different reasons why a pregnancy test may yield false positive results.

    Improper use of pregnancy test. One of the most common reasons at-home urine tests return false positives is that they were not done properly, usually because the instructions were misunderstood. It is important to read the manufacturer’s instructions carefully before taking a pregnancy test. Every test measures different levels of hCG.

    Evaporation lines. You must read pregnancy test results within the time frame specified on the test. It is not at all unusual for evaporation lines to appear on the test strip as your urine dries. If you read the results after the recommended time has elapsed, you may confuse the appearance of urine evaporation lines with a faintly positive test line.

    Expired pregnancy test. Always check the expiration date of the test before use. An expired test can yield false results.

    Testing too early. According to fertility experts, up to 70 percent of conceptions end in miscarriage. You may experience a chemical pregnancy without ever realizing it if the miscarriage occurs soon after conception and your menstrual period arrives on time. Testing too early is common among women who are trying to conceive and are anxious to know whether they have. While early-detection pregnancy tests can show a positive result just days after ovulation, it is advisable to wait until after your first missed period to test. This can save you and your partner from the potential heartbreak of finding out that you are not expecting as you had hoped.

  • Certain prescription medications can alter hCG test results. These include drugs used as part of fertility therapies, specifically drugs containing hCG. Other fertility therapies (such as clomiphene citrate and progesterone) and hormonal contraceptives should not affect the results. Medications that can affect hCG levels are:
    • hCG injections
    • Phenothiazine
    • Anticonvulsants
    • Anti-Parkinson’s medicines
    • Some tranquilizers
    • Some diuretics
    • Promethazine

    Contaminated urine sample. Another reason for a false positive test result is the presence of impurities in the urine sample, such as soap, detergent, or blood. Some pregnancy test kits come with cups. Washing the cup may inadvertently contaminate the urine sample if you do not wash out all the soap. If you do wash the cup, it’s crucial that you remove all soap or detergent before testing. It’s also important to know that these cups are generally sterile and don’t need to be washed before using.

    Another potential contaminant is blood, which may be present in urine for reasons other than your menstrual cycle. Kidney disease and bladder infections, for instance, can cause hematuria. When this happens, it’s possible that the test will yield false positive results.

    Medical conditions. Ectopic pregnancy, ovarian cysts, menopause, and other rare medical conditions can produce misleading results. A trophoblastic tumor is one example of a rare medical condition (only 3,000 cases occur in the United States each year) that can cause a false positive result. Trophoblastic tumors form when something goes wrong with the fertilization of an egg by the sperm. Instead of growing into a baby, the egg grows abnormally and becomes a tumor. These tumors develop in the reproductive tract and produce hCG.

    Recent pregnancy. You may get a false positive result if you have recently been pregnant (even if you did not carry to full term).

    How to Avoid a False Positive Test Result

    Fortunately, false-positive pregnancy test results are rare. Most experts recommend taking two at-home pregnancy tests before contacting your healthcare provider to confirm that you are pregnant. Trying different brands of tests can reduce the likelihood that you have misread the results.

    Most at-home pregnancy test kits are 99 percent effective. If you have followed the directions correctly, the odds are that your positive result is accurate and you are pregnant. However, it is important to remember that a positive result can be misleading. Also, when you take the test can make a huge difference in the result. It may be best to wait until after you have missed a period to take the test, even though you may be anxious to find out whether you are pregnant. Be sure to read the test’s directions thoroughly before use. Performing the test in the morning provides the best results, as hCG levels are highest at this time. If you are not sure about the results of your at-home pregnancy test, consider visiting the manufacturer’s web site or calling the manufacturer directly. Ultimately, however, you must visit your healthcare provider for an examination and quantitative blood testing to confirm your pregnancy.

    По материалам:



    Valium false positive pregnancy test

    False Positive Pregnancy Test

    Comments are closed.