7 things to know about ectopic pregnancy

Ectopic pregnancy is the most common cause of maternal mortality in the first trimester and a condition that women should know about. It occurs when a pregnancy implants outside of the uterine cavity. If left untreated, it can cause major internal bleeding and death.

Mitchell Creinin, chief of family planning at UC Davis Health, answered frequently asked questions about ectopic pregnancy.

Ectopic pregnancy happens when a pregnancy is located in any part of the body that is not the correct location, which is only inside the uterus.

Ectopic pregnancies can happen:

Most ectopic pregnancies are tubal ectopic pregnancies and cause early vaginal bleeding and/or pain on one side of the lower belly. However, these signs are vague and are more commonly related to non-ectopic pregnancy diagnoses.

Any person, early in pregnancy, with either of these symptoms should discuss them with a clinician to figure out if an evaluation for ectopic pregnancy is indicated or not.

For tubal ectopic pregnancies, treatment can be medications that dissolve the ectopic pregnancy tissue, or surgery. The smaller the pregnancy, the more likely that medications can be used. Other ectopic pregnancies are more complex and may require medications, surgery, or commonly a combination of these treatments.

When a pregnancy implants in the correct location of the uterus, the uterine muscle is designed to be able to stretch and grow as the pregnancy develops. Other organs, like the fallopian tubes, cannot grow that way and will eventually burst. The same will happen if the pregnancy is implanted in the cervix, the corner of the uterus or even the ovary. If left untreated, an ectopic pregnancy can result in life-threatening hemorrhage.

Luckily, today, in the U.S., this is very rare, with less than 50 people dying from an ectopic pregnancy per year. This low rate is a benefit of having relatively excellent access to care, compared to many developing countries. We currently have access to emergency medical systems, blood banks and emergency surgery to provide lifesaving care when needed.

Ectopic pregnancy can be diagnosed very early in pregnancy, but they still make up less than 2% of all pregnancies. For patients with symptoms that are worrisome to their clinician, testing can be done to try to figure out the pregnancy location early. Similarly, for patients with significant risk factors, especially a prior ectopic pregnancy, the clinician will usually do early testing (blood tests of pregnancy hormone quantities and an ultrasound exam) to evaluate the pregnancy location.

With a few unusual types of ectopic pregnancy, specifically a cesarean scar ectopic pregnancy (implanted in the cesarean scar) and an abdominal pregnancy (the pregnancy is implanted within the abdomen, usually on the bowel), the pregnancy can theoretically continue to the point in which the pregnancy can reach a point of viability. However, the risks and the potential morbidity and mortality to the mother are very significant; hence, every major medical organization recommends treatment to remove the ectopic pregnancy.

Prior ectopic pregnancies, prior tubal surgery and prior pelvic infection (PID) are all risk factors for ectopic pregnancy. Another risk factor is the contraceptive type at conception. The last one is a little tricky. All contraceptive methods decrease the overall risk of ectopic pregnancy because they decrease the risk of pregnancy. However, if conception occurs while using a hormonal implant, intrauterine device (IUD), injectable contraceptive (Depo-Provera, for example), or progestin-only birth control pill, the risk that that pregnancy is in the fallopian tube is increased compared to the risk in the general population.