What are the basics of an ectopic (tubal) pregnancy?

From the Guidelines

An ectopic pregnancy is a medical emergency that occurs when a fertilized egg implants outside the uterus, most commonly in a fallopian tube, and requires prompt treatment to prevent life-threatening bleeding. The diagnosis of an ectopic pregnancy involves a combination of blood tests for pregnancy hormone (hCG) levels, transvaginal ultrasound, and sometimes laparoscopy, as recommended by the American College of Radiology 1.

Key Points

• Symptoms of an ectopic pregnancy typically include abdominal pain (often one-sided), vaginal bleeding, and sometimes shoulder pain or dizziness.
• Risk factors include previous ectopic pregnancy, pelvic inflammatory disease, prior tubal surgery, smoking, and use of assisted reproductive technologies.
• Transvaginal ultrasound is the most useful method to evaluate the endometrium, early pregnancy, and adnexa, and is considered the single best diagnostic modality to assess for ectopic pregnancy 1.
• The absence of an intrauterine pregnancy when the hCG level is >3,000 mIU/mL should be strongly suggestive of an ectopic pregnancy, as suggested by Doubilet et al 1.
• Treatment options depend on how far the pregnancy has progressed and whether rupture has occurred, and may include medical management with methotrexate or surgical options such as laparoscopic salpingostomy or salpingectomy.
• After treatment, hCG levels should be monitored until they return to zero, and patients should avoid pregnancy for at least three months after methotrexate treatment, as recommended by the American College of Radiology 1.
• The risk of recurrence in future pregnancies is approximately 10%, making early prenatal care essential in subsequent pregnancies.

Diagnosis and Treatment

• A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible 1.
• The high specificity of adnexal findings suggestive of ectopic pregnancy includes the classic “tubal ring” 1.
• Medical management with methotrexate may be used for early, unruptured ectopic pregnancies with stable hCG levels below 5,000 mIU/mL and no fetal cardiac activity, as recommended by the American College of Radiology 1.
• Surgical options include laparoscopic salpingostomy (tube-preserving) or salpingectomy (tube removal), and emergency surgery is necessary for ruptured ectopic pregnancies causing internal bleeding.

From the Research

Definition and Presentation of Ectopic Pregnancy

• Ectopic pregnancy is a pregnancy that implants outside the normal uterine cavity 2, 3, 4.
• It most commonly presents with vaginal bleeding, abdominal or pelvic pain, and amenorrhea 2.
• Risk factors for ectopic pregnancy include abnormalities of the fallopian tube, prior ectopic pregnancy, and age over 35 years, but a significant number of patients with confirmed ectopic pregnancy will not have an identifiable risk factor 2, 4.

Diagnosis of Ectopic Pregnancy

• Evaluation includes quantitative serum hCG, blood type, and ultrasound 2.
• Ultrasound is necessary regardless of the hCG level 2.
• If a yolk sac or fetal pole is not seen in the uterus on ultrasound, this is considered a pregnancy of unknown location (PUL), which may represent an early, failed, or ectopic pregnancy 2, 4.
• Serial beta human chorionic gonadotropin levels, serial ultrasonography, and, at times, uterine aspiration can be used to arrive at a definitive diagnosis 4.

Management of Ectopic Pregnancy

• Patients with confirmed ectopic pregnancy but who are otherwise stable may be managed medically or surgically 2, 3, 5, 6.
• Medical management with intramuscular methotrexate is a great alternative with similar success rates and completely non-invasive 5.
• Surgical management via salpingostomy or salpingectomy is also an option 3, 6.
• Expectant management can be considered in some cases, but it still lacks studies for definitive conclusions 5, 6.
• Management must be customized to the clinical condition and needs of future fertility of the patient 6.

Special Considerations

• If the patient is hemodynamically unstable, resuscitation with blood products and early consultation of obstetrics/gynecology is necessary 2.
• A patient with diagnosed ectopic pregnancy should be immediately transferred for surgery if she has peritoneal signs or hemodynamic instability, if the initial beta human chorionic gonadotropin level is high, if fetal cardiac activity is detected outside of the uterus on ultrasonography, or if there is a contraindication to medical management 4.