(HealthDay News) -- An ectopic pregnancy occurs when a fertilized egg grows outside the uterus, most commonly in the fallopian tube.
The growing fetus eventually will cause the fallopian tube to burst, which can lead to life-threatening bleeding that could require immediate surgery.
Half of women who develop an ectopic pregnancy have no known risk factors, the American College of Obstetricians and Gynecologists says.
Those risk factors that are known include:
- Previous ectopic pregnancy.
- Prior fallopian tube surgery.
- Previous pelvic or abdominal surgery.
- Certain sexually transmitted infections.
- Pelvic inflammatory disease.
- Being 35 years or older.
- History of infertility.
- Use of assisted reproductive technology, such as in vitro fertilization.