Can an ectopic pregnancy cause a negative pregnancy test?

ectopic pregnancy risk factors

Pregnancy looks different for everyone. Sometimes, it results with a healthy baby and an addition to your family. Other times, pregnancy is not what you would expect it to be. Miscarriages happen, chemical pregnancies happen, ectopic pregnancies happens and, unfortunately, there isn’t much we can do to stop it. What we can do, though, is learn and become aware of the risks associated with pregnancy. Let’s start by diving into ectopic pregnancy.

What is an ectopic pregnancy?

An ectopic pregnancy is defined as a pregnancy in which the fetus develops outside of the uterus, typically in a fallopian tube. During a “typical pregnancy,” a fertilized egg attaches to the lining of the uterus. During an ectopic pregnancy, the fertilized egg grows outside the main cavity of the uterus.

Sometimes, an ectopic pregnancy will result in a miscarriage. More often, the fallopian tube stretches out and becomes very painful. Usually, ectopic pregnancies require immediate medical treatment because the growing fetus might cause the fallopian tube to rupture. Thanks to today’s modern medicine and technology, severe injury or death is extremely rare.

There are a few different types of ectopic pregnancies, depending on where the fertilized egg implants itself. In 98% of ectopic pregnancies, the fertilized egg implants in the fallopian tube. This type of ectopic pregnancy is known as a tubal pregnancy. Tubal pregnancies can be further classified on where in the fallopian tube the egg implants.

In about 5% of tubal pregnancies, the egg grows in the fimbrial end of the fallopian tube. More commonly (80%), the egg will grow in the ampullary section. In 12% of tubal cases, pregnancy happens in the isthmus and increases the chances of hemorrhage.

Next, there are non-tubal ectopic pregnancies. Accounting for 2% of all ectopic pregnancies, non-tubal ectopic pregnancies occur when the egg implants in other areas such as the ovary, the cervix, or the intra-abdominal region. In very rare cases, one egg implants inside the uterus and another implants outside. This is known as a heterotopic pregnancy. In some cases, the fertilized egg inside the uterus might still be viable, as long as hCG levels continue to rise.

Signs and symptoms of an ectopic pregnancy

How can you distinguish an ectopic pregnancy from a regular pregnancy? Some of the first warning signs of an ectopic pregnancy are vaginal bleeding and pelvic pain. What can be tricky is that these symptoms might feel very similar to those of a normal pregnancy.

The three main signs are vaginal bleeding, missed period, and abdominal pain. Unfortunately, only around half of women with an ectopic pregnancy will experience all of these. These symptoms typically appear around 6-8 weeks into pregnancy.

Some other signs include shoulder and neck pain, pain on one side of your body, and dizziness or nausea. If you experience any of these symptoms in early pregnancy, see your doctor immediately to make sure your fallopian tube has not ruptured.

Ectopic pregnancy causes

There are a few things that can lead to an ectopic pregnancy that are, unfortunately, out of our control. One of the most common causes is an infection or inflammation in the fallopian tube that can block the egg from traveling through and into the uterus. Similarly, left over scar tissue from a previous surgery can affect the way the egg travels through the tube.

Abnormal growths in the fallopian tube can also affect the shape of it and block the egg from traveling. Ectopic pregnancies are also common if you get pregnant while you have an IUD. While IUDs are over 99% effective in preventing pregnancy, there is a 0.2% failure rate per year, half of which are ectopic pregnancies.

One in every 50 pregnancies results in an ectopic pregnancy, or 2% of all pregnancies. Mothers between the ages of 35 and 44 are especially at risk for ectopic pregnancy, especially those who had one in the past. Those who have endometriosis are also at increased risk for ectopic pregnancies. This is because endometriosis can cause scar tissue to form resulting in a blockage in the fallopian tube.

Unfortunately, there is no way to prevent an ectopic pregnancy. To limit the risk of having an ectopic pregnancy, doctors recommend limiting your number of sexual partners. This, combined with using condoms, will prevent the chances of getting sexually transmitted infections and a pelvic inflammatory disease. Additionally, quitting smoking, especially when pregnant, will decrease the chances of an ectopic pregnancy.

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How early can you detect an ectopic pregnancy?

So, what happens with the results of a pregnancy test in the case of an ectopic pregnancy? Pregnancy tests do show positive results for an ectopic pregnancy. Pregnancy tests work by detecting a pregnancy hormone hCG in your urine. Because ectopic pregnancies still produce this hormone, a pregnancy test should still show a positive result. Although hCG is still produced during ectopic pregnancy, the levels of this hormone are lower and harder for a pregnancy test to pick up than in a regular pregnancy. For this reason, 1% of ectopic pregnancies will have a negative pregnancy test result.

Ectopic pregnancy treatment

An ectopic pregnancy can be seen in an ultrasound around 5-6 weeks into pregnancy 95% of the time. Sometimes, the pregnancy is too small to be picked up by an ultrasound early on. Treating an ectopic pregnancy looks different for every case, depending on the severity. The three main treatment options are expectant management, medication, and surgery.

In some cases, an ectopic pregnancy can go away on its own. If this is the case, expectant management is the best treatment option. This type of treatment is when your condition is carefully monitored by your doctor to evaluate if further treatment is necessary.

Next, there is a medication called methotrexate that your doctor might prescribe you. Methotrexate works by stopping your cells from growing and ending the pregnancy. This treatment option works for ectopic pregnancies in which the fallopian tube has not ruptured and requires follow up blood tests to make sure your hCG levels are falling. The most intense treatment option is surgery, which is used most commonly when the fallopian tube has ruptured and needs to be removed. This is an emergency procedure done with laparoscopy and under anesthesia to remove the pregnancy and sometimes the fallopian tube. It usually takes 4-6 weeks for women to fully recover from this surgery, but isn’t thought to reduce the chance of pregnancy in the future.

Ectopic pregnancies can be scary, confusing, and emotional. Moving forward after an ectopic pregnancy can be even harder. At Winx Health (formerly known as Stix), we’re here every step of the way to provide you with the resources and products you need to make your pregnancy experience better. 

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