Hx: A 33 yo female presents for possible pregnancy. She gives a hx of only 3 weeks and 5 days since her last menstrual cycle but notes that she had a positive pregnancy test 4 days ago. She complains of nausea and vomiting but denies any abdominal pain, vaginal bleeding, dysuria, or back pain. She states she is able to keep down liquids and denies any hematemesis. She does complain that the nausea is effecting her appetite and intake of food. Her history includes 3 prior pregnancies, one of which was an ectopic requiring surgical removal.
SocHx: No tobacco, alcohol, or drugs.
- General: sitting up in stretcher in no distress.
- Vitals: pulse 85, BP 110/80, RR 14, sat 100% RA, temp 98 (36.6 C)
- HEENT: normal
- Resp: clear bilaterally
- Cardiovascular: regular rate and rhythm, no murmurs, normal pulses, no peripheral edema.
- Abdomen: soft, non-distended, trace left lower quadrant tenderness, no guarding or rebound.
- Extremities: normal
- Neurological; normal
- Normal pregnancy
- Ectopic pregnancy
- Spontaneous miscarriage
- Non-pregnant (test error)
- Ovarian Cyst
- The patient undergoes testing which confirms a positive urine pregnancy test and normal urinalysis.
- Her labs show a normal H+H
- A pelvic ultrasound is ordered due to the patient’s history of prior ectopic and trace abdominal tenderness despite her early gestational age (by dates). The following images are obtained.
- The patient has immediate consultation with Gynecology and is taken to the OR for surgical removal of her 6wk 5day ectopic pregnancy.
- A laparoscopic salpingectomy, ectopic pregnancy removal, and evacuation of hemoperitoneum is performed without complication.
- She is discharged home in good condition after a brief period of observation.
Diagnosis: Left fallopian ectopic pregnancy
Ectopic pregnancy is the leading cause of pregnancy related death in the first trimester (PubMed). The incidence of ectopic pregnancy in the general population is reported as 2% (JAMA). However, it is as high as 18 percent of women in their first trimester who present with vaginal bleeding and abdominal pain, based on a retrospective study of women presenting to an emergency department. From this population, 76% had vaginal bleeding and 66% had abdominal pain. Additionally, up to 50% of women may have no symptoms or minimal symptoms prior to tubal rupture. (PubMed). The vast majority of these ectopic pregnancies, 93-97%, are located in the fallopian tubes.
This case highlights the importance of prior history as a risk factor for ectopic pregnancy. Although the patient had no complaints of vaginal bleeding or abdominal pain, she did have mild abdominal tenderness on exam. This is common in pregnancy and is often attributed to the corpus leuteal cyst. However, this patient had a history of prior ectopic pregnancy which is a known risk factor for development of subsequent ectopics. Additional risk factors include: current intrauterine device, prior tubal ligation, and in vitro fertilization. A high suspicion and low threshold for testing is important as physical examination and history have been demonstrated to be unreliable. (PubMed)
In the US, a combination of Trans-vaginal ultrasound and quantitative hCG testing guides the process of determining the presence of an ectopic pregnancy. Ultrasound findings that are diagnostic consist of visualization of a gestational sac and yolk sac. If these are seen in an extrauterine location, ectopic pregnancy is diagnosed. If they are seen intrauterine, then ectopic pregnancy can be safely excluded except in a patient who received in vitro fertilization. Those patients have a risk of heterotopic pregnancy. Visualization of a gestational sac alone is insufficient to make the diagnosis. HCG levels are helpful and are traditionally drawn on presentation and at 48-72 hours. In that time frame, a normal intrauterine pregnancy is expected to increase the HCG level by at least 66%. However, a smaller increase in HCG levels alone is not sufficient to diagnose an ectopic pregnancy.
In general, a protocol guided approach is recommended based upon these two results:
- Establish an accepted local HCG level for the discriminatory zone based upon the lab test and skill of the ultrasonographers. Typically, this is 2000 IU/L. However, some centers utilize a higher level of 3500 IU/L in order to reduce the chances of missing an early intrauterine pregnancy, while others choose a 1500 IU/L to reduce the chances of missing a potential ectopic.
- Obtain a trans-vaginal ultrasound. Trans-abdominal ultrasonography is incapable of obtaining sufficient images during the first trimester.
HCG below discriminatory zone: repeat in 48-72 hours
- HCG levels rise normally, repeat trans-vaginal US when discriminatory zone is reached.
- HCG levels rising abnormally, repeat trans-vaginal US.
- IUP seen, no treatment
- Ectopic seen, treat medically or surgically.
- No pregnancy seen, consider methotrexate treatment vs obtaining a 3rd HCG level and repeating US (in consultation with a Gynecologist for close follow up)
- HCG levels decreasing, diagnostic of miscarriage.
HCG level above discriminatory zone: trans-vaginal ultrasound is diagnostic and guides treatment.
- IUP seen, no treatment.
- No IUP seen, treat for ectopic.