Ectopic Pregnancy Symptoms, Causes, and Risk Factors

About 1 to 2% of all pregnancies in the U.S. are ectopic, which means "out of place." Though rare, the condition is the most dangerous cause of bleeding in the first trimester and can be life-threatening. Here's what you should know about ectopic pregnancy symptoms, causes, and risk factors.

What Is an Ectopic Pregnancy?

Ectopic pregnancies occur when a fertilized egg implants anywhere outside of the uterus—usually a fallopian tube, which is why it's also known as a tubal pregnancy. "Typically this happens if your fallopian tube is blocked by scar tissue or has an abnormality," writes Laura Riley, M.D., director of labor and delivery at Massachusetts General Hospital, in You and Your Baby: Pregnancy.

Rarely, the egg can also implant in an ovary, the cervix, the abdomen, or a C-section scar—none of which have the required space or the right tissue for a pregnancy to develop, says Mark D. Levie, professor of obstetrics & gynecology and women's health at the Albert Einstein College of Medicine.

What Causes Ectopic Pregnancy?

It's not always known why an ectopic pregnancy occurs, but damage to the fallopian tube could prevent the egg from reaching the uterus. You are more likely to have an ectopic pregnancy if you have one of the following risk factors:

• Previous ectopic pregnancy: "The risk of ectopic pregnancy happening a second time is 15-20%," says Dr. Levie
• Pelvic inflammatory disease
• Previous pelvic or abdominal surgery, such as removal of an ovarian cyst
• Pregnancy after reversal of tubal ligation
• Pregnancy through in vitro fertilization (IVF) or fertility drugs
• Certain STIs, such as chlamydia or gonorrhea
• Endometriosis
• Getting pregnant with an IUD in place
• Being 35 or older
• Smoking
• Douching
• Prior C-Section: "Ectopic pregnancies within the C-section scar, known as cesarean scar ectopics, are especially rare but the risk increases with the number of C-sections," says Dr. Rachel Fabacher Currault, an OB-GYN at the Women's Specialists of Houston at Texas Children's Pavilion for Women

You can still have an ectopic pregnancy if you don't have any of the risk factors. Indeed, about half of those who have an ectopic pregnancy don't have any known risk factors, says Dr. Levie.

Are Ectopic Pregnancies Viable?

Unfortunately, no. Ectopic pregnancies are never viable. Rather, they can be life-threatening.

If left untreated, ectopic pregnancies can pose major health problems for the pregnant woman. "An ectopic pregnancy is extremely dangerous because it can rupture the fallopian tube and lead to severe bleeding and possibly death," says Yen Tran, M.D., an OB-GYN at MemorialCare Orange Coast Medical Center in Fountain Valley, California. Most ectopic pregnancies are diagnosed in time to prevent complications, but in the U.S., the condition still causes about 50 deaths a year, Dr. Riley notes.

That said, it's important to note this number could rise as abortion care, also known as reproductive healthcare, becomes less accessible. This is expected to occur in many states due to the overturning of Roe v. Wade.

What Are the Most Common Ectopic Pregnancy Symptoms?

Early symptoms of tubal pregnancy imitate those of normal pregnancy, such as a missed period, breast tenderness, nausea, and fatigue. But as the condition develops, many experience the following signs and symptoms of ectopic pregnancy:

• Sudden, severe, sharp pain in the abdomen or pelvic area
• Vaginal bleeding
• Shoulder pain
• Fainting or feeling faint
• Weakness or dizziness

If your only symptoms are mild pelvic pain or spotting, contact your healthcare provider to schedule an appointment, since these can be normal in early pregnancy, says Crystal Berry-Roberts, M.D., an OB-GYN at Austin Regional Clinic in Austin, Texas. But symptoms such as heavy bleeding, severe pelvic pain, feeling lightheaded, or instability on your feet warrant an immediate visit to the emergency room, she says. That's because they signal a late-stage ectopic pregnancy, which has the potential of bursting the fallopian tube.

Another worrisome symptom is an odd pain in the tip of your shoulder, which could be caused by internal bleeding that irritates nerves that travel to your shoulders, according to Dr. Riley.

You're much more likely to save your fallopian tube—and perhaps your own life—by treating tubal pregnancy early, she says.

When Do the Signs of an Ectopic Pregnancy Usually Appear?

Most people experience tubal pregnancy symptoms between four and 12 weeks of pregnancy. They usually appear around week six. Some, however, do not have any early symptoms of ectopic pregnancy; they only learn about the condition during an ultrasound scan. This is especially common if the ectopic pregnancy is somewhere besides the fallopian tube.

How Do You Diagnose an Ectopic Pregnancy?

Visit your doctor right away for symptoms like heavy bleeding, severe pelvic pain, shoulder pain, or lightheadedness. Alert the provider about any risk factors for ectopic pregnancy you may have. They will likely do a pelvic exam, ultrasound, and blood work (to check your hCG levels) to determine if your pregnancy is ectopic. Depending on the severity, tubal pregnancies are treated through medication (methotrexate), laparoscopic surgery, or abdominal surgery.

Can You Get Pregnant After an Ectopic Pregnancy?

Having an ectopic pregnancy does put you at risk for having another one, but the good news is more than half of individuals who have had an ectopic pregnancy in the past go on to have one or more healthy pregnancies in the future, according to Dr. Riley. Speak with your healthcare provider to discuss your chances of having a pregnancy that develops in the proper place.

How Do You Prevent Ectopic Pregnancy?

Sadly, there's no definite way to prevent an ectopic pregnancy. "However, avoiding conditions that may cause scarring of the fallopian tubes may help reduce your risk," says Dr. Berry-Roberts. Her advice: Limit sexual partners, practice safe sex to protect yourself from STIs, and get early diagnosis and treatment for any STIs. It's also a good idea to quit smoking and douching. And Dr. Levie stresses visiting the doctor as soon as you find out you're pregnant, so you can confirm the pregnancy is located in the right place.