Ectopic Pregnancy

Key Features

Essentials of Diagnosis

• Amenorrhea or irregular bleeding and spotting

  • Pelvic pain, usually adnexal

  • Adnexal mass by clinical examination or ultrasound

  • Failure of serum beta-human chorionic gonadotropin (β-hCG) to double every 48 hours

• No intrauterine pregnancy on transvaginal ultrasound with serum β-hCG > 2000 mU/mL

General Considerations

• Occurs in approximately 2% of first-trimester pregnancies; about 98% of cases being tubal pregnancies

• Implantation may also occur in the peritoneum or abdominal viscera, the ovary, and the cervix

• Undiagnosed or undetected ectopic pregnancy is one of the most common causes of first-trimester maternal death in the United States

Demographics

• Conditions that prevent or inhibit migration of the fertilized ovum to the uterus can predispose to ectopic implantation

• Specific risk factors

  • History of infertility

  • Pelvic inflammatory disease

  • Ruptured appendix

  • Prior tubal surgery

Clinical Findings

Symptoms and Signs

• Lower quadrant pain that is sudden, stabbing, intermittent, and does not radiate

• Backache may be present during attacks

• Shock in about 10%, often after pelvic examination

• At least two-thirds of patients give a history of abnormal menstruation; many have been infertile

• Blood may leak from the tubal ampulla over days

• Persistent vaginal spotting is usually reported

• A pelvic mass may be palpable

• Abdominal distention and mild paralytic ileus are often present

Differential Diagnosis

• Acute appendicitis

• Intrauterine pregnancy (threatened abortion)

• Pelvic inflammatory disease

• Ruptured corpus luteum cyst or ovarian follicle

• Urinary calculi

• Tubo-ovarian abscess

• Gestational trophoblastic neoplasia, eg, hydatidiform mole

• Shock or sepsis due to other causes

Diagnosis

Laboratory Tests

• Complete blood count may show anemia and slight leukocytosis

• Serum β-hCG levels are lower than expected for a normal pregnancy of the same gestational age

• Serum β-hCG levels may rise slowly or plateau rather than double every 48 hours as in viable early pregnancy or fall as in spontaneous pregnancy loss

Imaging Studies

• Transvaginal ultrasound

  • May occasionally identify the ectopic pregnancy

  • A β-hCG level of ≥ 2000 mU/mL can indicate an ectopic pregnancy if no products of conception are detected within the uterine cavity

• Transabdominal ultrasound

  • A β-hCG level of 6500 mU/mL with an empty uterine cavity is highly suspicious

Diagnostic Procedures

• Diagnosis should be suspected when postabortal tissue examination fails to reveal chorionic villi

• Steps must be taken for immediate diagnosis, including prompt microscopic tissue examination, ultrasonography, and serial β-hCG titers every 48 hours

Treatment

Medications

• Intramuscular methotrexate (50 mg/m²)

  • Acceptable for early ectopic pregnancies < 3.5 cm and unruptured, ...