Ectopic pregnancy (EP) is the leading cause of maternal death in the first trimester. Major risk factors include history of pelvic inflammatory disease, surgical procedures on the fallopian tubes, including tubal ligation, previous EP, diethylstilbestrol exposure, intrauterine device use, and assisted reproduction techniques. The most common extrauterine location is the fallopian tube. This diagnosis must be considered in every woman of childbearing age presenting with abdominal pain and/or vaginal bleeding.
The classic triad of abdominal pain, vaginal bleeding, and amenorrhea used to describe EP may be present, but many cases occur with more subtle findings. Presenting signs and symptoms may be different in ruptured versus nonruptured EP. Only 90% of women with EP complain of abdominal pain; 50% to 80% have vaginal bleeding; and only 70% give a history of amenorrhea. The pain described may be sudden, lateralized, extreme, or relatively minor and diffuse. The presence of hemoperitoneum causing diaphragmatic irritation may cause the pain to be referred to the shoulder or upper abdomen. Presenting vital signs may be entirely normal even with a ruptured ectopic pregnancy. There is poor correlation with the volume of hemoperitoneum and vital signs in EP. Relative bradycardia, as a consequence of vagal stimulation, may be present even in cases with rupture and hemoperitoneum. Physical examination findings are highly variable. The abdominal examination may show signs of localizing or diffuse tenderness with or without peritoneal signs. The pelvic examination findings may be normal but more often shows cervical motion tenderness, adnexal tenderness with or without a mass, and possibly an enlarged uterus. Vaginal bleeding, ranging from spotting to heavier bleeding, is often present. Fetal heart tones may be heard in cases of EP beyond 12 weeks of gestation.
Diagnosis and Differential
The definitive diagnosis of EP is made either by US or by direct visualization during surgery. The diagnosis of pregnancy is central to the diagnosis of possible ectopic pregnancy and needs to be confirmed first. Urine pregnancy testing (for urinary β-human chorionic gonadotropin [β-hCG]) is a qualitative screening test with a threshold for detection of > 20 mIU/mL of β-hCG. Urine qualitative testing is 95% to 100% sensitive and specific as compared with serum testing. Dilute urine, particularly when β-hCG levels are < 50 mIU/mL, may result in a false-negative result. Qualitative serum testing for the diagnosis of pregnancy is virtually 100% sensitive for detecting β-hCG levels > 5 mIU/mL and should be performed when the diagnosis of EP is considered but urine results are negative.
The primary goal of US in suspected EP is to determine if an IUP is present, since US cannot rule out the presence of EP. The transabdominal examination is usually performed first due to its wider field of view; the transvaginal examination is performed if the transabdominal examination is not diagnostic. When US reveals an unequivocal IUP and no other abnormalities, EP is effectively excluded unless the patient is at high risk for heterotopic pregnancy. Actual visualization of an EP with US occurs in a minority of cases. Sonographic findings of an ...