A 32-year-old woman presents with lower abdominal pain and vaginal bleeding for two days. She has been nauseous, vomited twice (nonbloody or bilious), and has soaked through 13 pads that day alone.
She denies fever, chills, diarrhea, constipation, syncope, palpitations, or vaginal discharge. She had a tubal ligation three years before, after the delivery of her fourth child by C-section. Her heart rate is 136 beats per minute, and her blood pressure is 103/60 mm Hg. She has a positive urine pregnancy test. The photograph shows the results of bedside ultrasound.
What is the most likely diagnosis, and how common is this condition?
Diagnosis: Ectopic Pregnancy
Ectopic pregnancy is a common diagnosis in the ED, and it can have life-threatening complications if not diagnosed accurately and expeditiously. It is estimated that two percent of all pregnancies are ectopic, at a cost of approximately $1.1 billion a year.
Ectopic pregnancies occur when the fertilized egg implants outside of the uterine cavity. This is typically the result of previous Fallopian tube damage. The uterus is designed to stretch with the demands of the growing fetus, and implantation outside the uterus can lead to organ rupture. If left untreated, ectopic pregnancy is ultimately fatal to the fetus and potentially the mother. Before the 20th century, complications from ectopic pregnancies were often fatal. Despite medical advancements, hemorrhage from ruptured ectopic pregnancy is still the most common cause of death for pregnant women in the first trimester, and is responsible for nearly 10 percent of all pregnancy-related deaths.
Many risk factors have been shown to increase the risk of ectopic development: previous history of pelvic inflammatory disease (PID), previous personal history of ectopic pregnancy despite treatment modality, history of tubal surgery including ligation, use of fertility drugs, in vitro fertilization, conception with intrauterine device (IUD), increasing age, smoking, prior abdominal surgery, in utero diethylstilbestrol (DES) exposure, multiple sexual partners, and a T-shaped uterus. Most women diagnosed with an ectopic pregnancy, however, have no risk factors.
The most common site of ectopic pregnancies is the Fallopian tube (98%), specifically in the ampulla (80%+), followed by the isthmus (12%), fimbria (5%), and the cornual and interstitial area (2%). Nontubal ectopic implantation sites are rare, but can occur in the abdomen (1.4%), ovary (0.2%), or cervical region (0.2%).
Patient presentation in the ED will depend on the gestational age of the conceptus and whether rupture of the ectopic pregnancy has occurred. In the ED, as many as 16 percent of first-trimester patients with vaginal bleeding or abdominal pain are ultimately diagnosed with ectopic pregnancy. (CMAJ 2005;173:905.) The classic presentation of vaginal bleeding, abdominal pain, and amenorrhea are present in less than 50 percent of cases. Surprisingly, in more than half of cases, patients present without a history of vaginal bleeding, but 75 percent complain of abdominal tenderness, and 50 percent have a palpable adnexal mass. Hemodynamically unstable patients (20% of ectopic patients) should be managed according to standard resuscitation protocols because this highly suggests rupture.
Laboratory evaluation should include a complete blood count, beta HCG, type, and Rh factor. Renal and hepatic function tests should be performed if methotrexate therapy is likely. A pelvic ultrasound should be performed to identify if an intrauterine pregnancy exists. If the beta HCG is higher than the “discriminatory zone” of 1500–2000 mIU/mL (Obstet Gynecol 1981;58:156), early products of conception should be visualized via transvaginal ultrasound (or higher than 6500 mIU/mL by transabdominal ultrasound). If the beta HCG is above the discriminatory zone and no intrauterine pregnancy is visualized, this suggests an ectopic pregnancy or nonviable pregnancy. Absence of an intrauterine pregnancy and beta HCG levels below the discriminatory zone can represent a normal early, nonviable, or ectopic pregnancy, with as many as 40 percent being diagnosed as ectopic. The risk of a heterotopic pregnancy (simultaneous intra- and extrauterine pregnancies) in women who have had assistive reproductive technology treatment is as high as one percent, but is only one in 30,000 pregnancies in those who have not.
If left untreated, ectopic pregnancies can follow three courses: spontaneous resolution, tubal “abortion” (expulsion into abdominal cavity where the conceptus is resorbed or implants inside abdomen), or spontaneous rupture, which can result in massive hemorrhage or death. Management is expectant, medical/ pharmacologic, and surgical.
Because of the risk of infertility caused by surgical treatment, more conservative approaches have been advocated. Candidates for expectant management must be fully compliant, understand and accept the risks of potential rupture, be asymptomatic and hemodynamically stable, and have evidence of spontaneous resolution including declining bHCG levels. Failure rates as high as 50 percent in ideal patients have been reported.
Ideal candidates for medical therapy (i.e., methotrexate) are reliable and able to comply with close follow-up, are hemodynamically stable with a bHCG ≤5000 mIU/mL, have no fetal cardiac activity or signs of impending rupture (e.g., persistent abdominal pain), conceptus size less than 3 to 4 cm on ultrasound, and have no contraindications to methotrexate. Patients with an ectopic pregnancy located in the corneal or interstitial area, cervix, or ovary may benefit from methotrexate therapy as opposed to surgical treatment because of the increased risk of operative hemorrhage.
Surgical therapy of an ectopic pregnancy can be either salpingectomy or salpingostomy, performed laparoscopically or by open technique.
This patient was diagnosed with a ruptured ectopic pregnancy and taken emergently to the operating suite. A salpingectomy was initially performed, but because of uncontrolled intraoperative bleeding, the patient required a salpingo-oophorectomy, and was discharged uneventfully.