What Is an Ectopic Pregnancy and Why Does It Happen?

Ectopic Pregnancy happen

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What is an ectopic pregnancy?

In a normal pregnancy, a fertilized egg implants in the wall of the uterus, where a fetus has room to grow. An ectopic (or “tubal”) pregnancy occurs when a fertilized egg implants somewhere outside of the uterus. In most, but not all, cases this happens in one of the two fallopian tubes. An ectopic pregnancy can be dangerous and even life-threatening. This is because as the pregnancy grows, it doesn’t have enough room. It can cause the tube to rupture, which leads to internal bleeding and possibly shock.

Why an ectopic pregnancy happens?

Ectopic pregnancies are rare, occurring in only 1.3-2.4% of pregnancies. It is not always clear why an ectopic pregnancy happens. In fact, almost half of women who experience an ectopic pregnancy have no risk factors. However, some risk factors are known. For example, anyone who has had an ectopic pregnancy or surgery on the fallopian tubes in the past is at higher risk. Other risk factors for ectopic pregnancy include pelvic inflammatory disease, endometriosis, and use of fertility drugs and in vitro fertilization. Ectopic pregnancy should always be considered in a woman who becomes pregnant despite having a tubal surgery for sterilization (“having her tubes tied”).

What are the signs and symptoms of an ectopic pregnancy?

In the beginning, an ectopic pregnancy feels like any normal pregnancy, with tender breasts, a missed period, and feeling tired. But eventually other signs and symptoms occur, such as vaginal bleeding and pain. A woman with an ectopic pregnancy will probably experience cramping on one side of the lower abdomen and pelvis, but low back pain and general pelvic pain can also occur. It is also possible that a woman may not experience any symptoms until it ruptures.

In the event of a ruptured ectopic pregnancy, the lower abdominal and pelvic pain becomes more severe. This can happen suddenly. There may also be shoulder pain, dizziness, weakness, and fainting. On examination by a clinician, the woman’s abdomen will be tender to the touch, and a gynecological exam will be very painful. Additionally, her vital signs (blood pressure, heart rate, and respiratory rate) may be abnormal.

Ectopic pregnancies are rare, occurring in only 1.3-2.4% of pregnancies. It is not always clear why an ectopic pregnancy happens. In fact, almost half of women who experience an ectopic pregnancy have no risk factors.

To recap, signs of a ruptured ectopic pregnancy include:

  • Severe pelvic or lower abdominal pain, particularly if limited to one side
  • Shoulder pain
  • Dizziness, weakness, or fainting
  • Difficulty breathing
  • Abnormal heart rate or blood pressure

Any of these signs and symptoms needs to be addressed immediately.

How do I know if I have an ectopic pregnancy?

After you know you’re pregnant, doctors can use an ultrasound to see if the pregnancy is growing in the uterus (intrauterine pregnancy) or somewhere else (extrauterine pregnancy). Studies suggest that around 88% of ectopic pregnancies can be diagnosed by ultrasound.

Because early ectopic pregnancies aren’t always seen with an ultrasound, a test for the level of a hormone called human chorionic gonadotropin (hCG) may also be helpful. This hormone is secreted by the developing embryo and placenta. By watching how much the hCG level changes over a couple of days, doctors can use this to help determine if there’s an ectopic pregnancy. In other words, if they can’t see a pregnancy in the uterus and the hCG level doesn’t behave like it should, this could indicate that there is an ectopic pregnancy.

Once the diagnosis of ectopic pregnancy has been made, the pregnancy must be terminated. Not all ectopic pregnancies need to be treated with surgery (you can read more here about treatment options), but a ruptured ectopic pregnancy needs to be treated with surgery immediately in order to avoid a life-threatening complication.

Mandy Armitage
Dr. Mandy Armitage is a board-certified physician and writer. She is passionate about education, for patients and clinicians alike. In her free time, she enjoys spending time with her family, reading, traveling, and attending live music events.

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