Pregnancy Test: What Can Cause a False Positive Result?

Although a false positive result from a home pregnancy test is rare, it can still happen. Here are the reasons why a positive result can occur when you are actually not pregnant.

Today, most home pregnancy tests boast about 99% reliable. Responsible for verifying the presence of thehCG hormone – human chorionic gonadotropinthe hormone produced by the placenta when a woman is pregnant – home pregnancy tests can detect pregnancy based on urine 12 to 14 days after conception. hCG levels normally double every 72 hours for 8 to 11 weeks of pregnancy, then remain constant and then fall after delivery.

On the same subject

15 foods to eat during pregnancy

If the pregnancy hormone is present at the time of the urine test, it triggers a chemical reaction that indicates whether or not you are pregnant. Oftentimes, pregnancy is indicated by the appearance of two lines, and a negative result is indicated by a single line.

While these home tests are reliable in most cases, they can beat the time of the result, a false positive result appears. A deeply traumatic experience, both for women who really want to get pregnant and for those who absolutely don’t. Here are the reasons that could explain this strange result.

You let the test sit for too long

When conducting a test at home, it is important to strictly follow the instructions given in the instructions for use, and especially the waiting times. Obviously, if you don’t wait long enough, the result will not be reliable. But vice versa, if you let it sit for too long, thatUrine on the test can evaporate and give the impression of two lines instead of one.

The pregnancy test has expired

Another common reason why women get a false positive result is: Expiry date pregnancy test. When the date has passed, the chemical responsible for detecting hCG can no longer do it correctly and therefore the risk of error is higher.

You are undergoing fertility treatment

If you are having fertility treatment, the medicine you are taking or the injections used for in vitro fertilization (IVF) may contain hCG. If you test too soon after taking medication or after an injection, you may get a false positive result.

It can happen to women”who are very motivated and trying to get pregnant and they will often take the pregnancy test early and see a positive result which of course is very exciting for them at firstsays Zev Williams associate professor of obstetrics and gynecology to the journal shine. But it could just be the result of the fertility drugs they were taking. This is something we warn patients about so they don’t get false hope when they see the positive test..”

You still have hCG in your blood after giving birth or miscarriage

According to a study by lancet published in April 2021, concerning miscarriages one in 10 women in their lifetimewith an estimated 23 million miscarriages worldwide.

After childbirth or miscarriage, hCG can remain in the body for several months. According to another study published in The Journal of Clinical Endocrinology and Metabolism, it takes four to six weeks for levels to return to normal. In fact, part of the placenta can still be present and therefore release hCG for a period of time.

You had an ectopic pregnancy

An ectopic pregnancy is when the pregnancy occurs outside the uterus, ieA fertilized egg cell develops outside the uterusoften in the fallopian tubes, cervix, or ovaries.

The embryo then produces hCG, indicating a positive result, but that Pregnancy is not viable : An embryo cannot develop in any area other than the uterus. An ectopic pregnancy can even be dangerous for the mother’s health.

Its main symptoms are severe abdominal and pelvic pain during pregnancy, abnormal vaginal bleeding, dizziness or shoulder pain. If you experience any of these symptoms, do not hesitate to contact your doctor.

Sources :

  • Miscarriage: the epidemiological, physical, psychological and economic costs of early pregnancy loss, The lancetApril 2021
  • Hypothesis: Persistently elevated hCG levels cause gestational ovarian hyperstimulation associated with prolonged postpartum hyperandrogenism in mothers of aromatase-deficient babies, The Journal of Clinical Endocrinology and Metabolism, August 2013

Also read:

Widget is loading

Widget is loading

Subscribe to the Top Santé newsletter to receive the latest news for free

Leave a Comment