In this article, Dr. Gleaton shares how pregnancy tests work, what medications could affect pregnancy test results, and when to talk to your doctor.
By OBGYN and fertility expert Dr. Kenosha Gleaton
Taking a pregnancy test can be a nerve-wracking experience, and you want to be confident when reading the results. We’ve already covered the most common questions in our guide to peeing on a stick (POAS), but now it’s time to cover what medications could affect your pregnancy test results.
How medications affect pregnancy test results
To recap, pregnancy tests work by detecting the pregnancy hormone, hCG, in urine. If the pregnancy test detects a certain level of hCG, it will show a positive result. hCG is made when a fertilized egg implants in the uterus, usually around 10 days after conception, and increases every day in early pregnancy.
If you’re taking a medication that contains or affects hCG production, it’s possible that you could receive a false pregnancy test result. This means you could receive a positive test without actually being pregnant, or (more rarely) a negative test when you are pregnant.
What medications may affect pregnancy test results
Most medicines, including over-the-counter and prescription, should not affect the results of a home pregnancy test. But medicines that have the pregnancy hormone hCG in them may give a false positive test result. This includes some medicines given for infertility treatments—often called the “trigger shot” and sold under the brand names Novarel, Ovidrel, Pregnyl, and Profasi.
What to do if you suspect medication is affecting pregnancy test results
If you suspect your medication may be affecting your pregnancy test results, you should consult with your doctor. Your doctor can run a blood test and perform a transvaginal ultrasound to give you a definite answer on whether or not you’re pregnant.
If you’re on medications for fertility treatments, it’s important you don’t interfere with your medication routine without supervision from your doctor.
When to call your doctor
If you believe you’ve been getting multiple false positives or false negatives, you should see your doctor. This is especially important if you are participating in fertility treatments or are showing symptoms of pregnancy, but receiving negative test results.
Some false pregnancy test results could be a result of a hormone imbalance, including PCOS, a chemical or ectopic pregnancy, evaporation lines, and more. Make sure you’re following your test instructions correctly to avoid any user error.
Follow instructions and know when to seek advice
It’s important to follow directions exactly when taking pregnancy tests, otherwise you could end up with a false positive or false negative result. If you’re following the instructions correctly and you’re still concerned that your results are incorrect, you should consult your doctor. Many fertility medications and occasionally some OTC or prescription drugs could cause a false pregnancy test result, but a blood test and transvaginal ultrasound will help rule this out.