Every Explanation for a False Positive Pregnancy Test
If you take a home pregnancy test and the result is positive, a million thoughts may start running through your mind. It can be an overwhelming thing to experience, especially if you weren’t trying to conceive. You might feel a mix of excitement, terror and joy, or you may even immediately start thinking of baby names and what kind of car seat you want to buy. Whatever your reaction - it’s normal.
If you take a pregnancy test at home and the result is positive, it’s important to see a doctor straight away to confirm the results and determine your next steps. If the result turns out to be a false-positive, it can make the situation even more overwhelming. It is more common than most people realize to have a false positive, so we’ve listed all the reasons below of why you could get a false positive result to help you feel more prepared.
1. Chemical Pregnancy
Early pregnancy loss is one of the most common reasons women have a false positive pregnancy test. A chemical pregnancy is a form of early miscarriage, which usually occurs before the 5th week of pregnancy. It can cause a positive pregnancy test result that turns into a negative result just a few weeks later.
This type of miscarriage occurs because the fertilized egg doesn’t fully implant itself into the uterine wall. The cause can also be due to problems with the baby’s chromosomes. A chemical pregnancy is very common and many women do not even know that they have experienced the miscarriage until they have had an ultrasound scan and seen a doctor. Many women do however experience light bleeding, with or without pain, which usually starts after a positive home pregnancy test.
Most of the time, no treatment is needed for a chemical pregnancy. The loss will resolve naturally on its own and you and your partner are free to try again after your next period if you are trying to conceive.
2. Ectopic Pregnancy
An ectopic pregnancy is a common form of early miscarriage. It occurs when the fertilized egg implants itself outside the uterus, most often in one of the fallopian tubes. This is why it is also sometimes called a tubal pregnancy. Since the egg cannot survive outside of the uterus, it must be removed.
It’s often not clear why exactly an ectopic pregnancy occurs, but there are some conditions that pose a higher risk for ectopic pregnancy. It’s important to know the symptoms of an ectopic pregnancy, because it can be life threatening. If you experience any of these symptoms, it is important to seek emergency help.
There are three main treatments for an ectopic pregnancy:
- Expectant management - this is where you are carefully monitored to see if the fertilized egg dissolves by itself.
- Medication - an injection of a medicine called methotrexate is used to stop the pregnancy growing.
- Keyhole surgery - this is also called a laparoscopy, and it is performed under a general anesthetic. The fertilized egg will be removed, usually along with the affected fallopian tube.
Going through an ectopic pregnancy can be emotionally and physically draining and challenging, but there are support services available that can help you recover.
3. Molar Pregnancy
A molar pregnancy is a rare pregnancy complication that causes a non-cancerous tumor to grow in the uterus. When this occurs, the pregnancy is nonviable and must be terminated to remove the tumor. Common symptoms are vaginal bleeding in the first trimester, that goes from brown to bright red, and severe nausea and vomiting. A molar pregnancy is also known as a hydatidiform mole.
4. Existing Medical Conditions
There are certain medical conditions that can not only cause a false positive pregnancy test, but mimic pregnancy symptoms as well. Below is a list of all of the known medical conditions that can be a reason for a false positive.
- Kidney disease
- Ovarian cancer (and in rare cases breast cancer, stomach cancer, liver cancer, or lung cancer)
- Urinary tract infection
- Ovarian cysts
- Pituitary gland or hormone disorders
- Rare antibodies that produce phantom hCG (when the antibodies bind with the molecules in a pregnancy test and signal higher levels of hCG than there are)
5. Evaporation Lines
Evaporation lines are actually very common with certain at-home pregnancy tests. They are often confused for a faint positive result. An evaporation line is colorless. They are seen on a home pregnancy test once the urine has dried or evaporated. This typically happens if you read the test result after the recommended time frame. A faint line that is either blue or pink, depending on the test, is a positive.
6. Certain Medicines
Below is a list of medications that could cause a false positive pregnancy test.
- Antipsychotics (including prochlorperazine or perphenazine)
- Anti-seizure medicine such as carbamazepine
- Anti-anxiety medications (like Valium or Xanax)
- Progestin-only birth control (like Errin or Heather)
- Fertility medications (examples are Pregnyl and Profasi; most fertility treatments involved hCG injections)
7. User Error
Not taking a home pregnancy test correctly can also result in a false-positive result and sometimes a false negative as well. Make sure the tests you are using aren’t expired and you are following all of the directions exactly as written. Sometimes not leaving the dipstick in the urine cup or urine stream for the right amount of time or testing too early can give you inaccurate results.
Always follow up with your healthcare provider if you think you may be pregnant.
How Pregnancy Tests Work
The body of a woman who is expecting a baby will start producing a hormone called hCG or human chorionic gonadotropin. The hCG hormone is made by the placenta during pregnancy in order to thicken the uterine lining to support the embryo and prevent menstruation. It can be detected in the urine by a pregnancy test or by a blood test. The hormone levels rise throughout the pregnancy. If hCG levels dip, this could potentially mean a loss or miscarriage.
Finding Support After a False Positive Pregnancy Test
If you and your partner are trying to conceive, it can be heartbreaking to experience a false positive pregnancy test. This can be especially true if you have gone through struggles with your fertility. It’s important to take care of your mental health as well as your physical health during this difficult time, and seek support from family, friends, or a mental health professional.