Gynecology: Ectopic Pregnancy

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Ectopic pregnancy is potentially life threatening but often misdiagnosed. It must be suspected in any woman with vaginal bleeding and lower abdominal pain. Ruptured ectopic is a true medical emergency.

1. General Information.
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1. Risk factors. History of ectopic, PID, tubal or pelvic surgery, pelvic surgery, infertility, endometriosis, anatomical anomalies, DES exposure, cigarette use, older age. Although IUDs do not increase the absolute risk of ectopic, accidental pregnancies with an IUD are more likely to be ectopic than intrauterine. Fertility treatment leads to a heterotopic pregnancy (intrauterine with coexistent ectopic) in up to 3%.
2. Differential diagnosis. Early intrauterine gestation with implantation bleeding, spontaneous abortion ruptured functional ovarian cyst, appendicitis, PID, other gynecological and abdominal conditions caus-ing pain. See Chapter 15 for further information about the acute abdomen.

2. Evaluation.
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1. Symptoms. Abdominal pain (98%), amenorrhea (65%), vaginal bleeding/spotting (80%), with or without symptoms of early pregnancy. Note that not all patients report amenorrhea or vaginal bleeding! Patients may have nausea, vomiting, dizziness, syncope, hypovolemic shock, referred shoulder pain, tenesmus and low-grade fever. Usually occurs 6-8 weeks after LMP.
2. Exam. Check vital signs. Blood pressure and pulse may be normal even with significant intraperitoneal bleeding! Pelvic exam may be normal; only 50% have adnexal mass. Uterus may be enlarged secondary to deciduation or blood. Cervical motion tenderness may be found as well as doughy cul-de-sac secondary to bleeding. Marked abdominal tenderness with guarding and rebound suggests ruptured or bleeding ectopic. When an acute abdominal emergency or hemorrhagic shock is suspected, immediate surgical consultation is indicated.
3. Lab tests. Pregnancy test: Urine pregnancy test may miss a very early ectopic (limit 50 mIU/ml). A serum quantitative beta-hCG is sensitive to 5 mIU/ml. If possible, a quantitative serum HCG should be done. Obtain CBC, type and screen, and transvaginal ultrasound.

3. Correlate ultrasonography with the serum quantitative HCG.
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1. Beta-hCG <1500 mIU/ml. Ultrasonography may not show evidence of a gestational sac. If stable and ultrasound is negative, these patients can be followed-up as per section 4 below. But do not assume a benign course if the beta-hCG is low. These patients can still rupture an ectopic if one is present.
2. HCG >1500. If the beta-hCG is above 1500 mIU/ml and the sonographer is reasonably skilled, an intrauterine pregnancy should be detectable by transvaginal ultrasonography in 95% of cases. If an intrauterine sac is not visible with a serum beta-hCG >1,500, suspicion of ectopic is markedly increased.
3. beta-hCG >3500. The adnexal gestation is often not visible until the Beta HCG is 3500 to 6500 mIU/ml.
4. beta-hCG >6000 mIU/ml. If the patient has a beta-hCG of > 6000 mIU/ml and there is no intrauterine gestational sac seen, it is presumptive evidence of an ectopic pregnancy.
4. Follow-up for the patient in whom the diagnosis of ectopic cannot be proven or ruled out on the first visit.
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1. In a stable, reliable patient, if ultrasonography is unable to exclude ectopic pregnancy, obtain serial quantitative beta-hCG every 48 hours and follow clinical exam. The beta-hCG should approximately double in 48 hours. In an unreliable patient, treat as presumed ectopic.
1. If beta-hCG rises by >66% in 48 hours, the pregnancy is continuing; repeat the ultrasound when the beta-hCG is >1,500 to differentiate between ectopic and intrauterine (should see intrauterine at this point). If still indeterminate, follow-up in another 48 hours with repeat quantitative beta-hCG and ultrasound. If the beta-hCG is not rising or is falling, the pregnancy is likely non-viable and a D&C should be done to look for chorionic villi.
2. Culdocentesis is used rarely since the advent of transvaginal ultrasonography. Hemoperitoneum (>5 ml of non-clotting blood) in combination with a positive pregnancy test is 99% predictive of a ruptured ectopic.
3. Serum progesterone levels are not very helpful.
5. Treatment
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1. Primary treatment is surgical. Tube-sparing surgical techniques such as laparoscopic salpingostomy allow for preservation of fertility with little increase in risk for recurrent ectopic.
2. Methotrexate injection is a nonsurgical treatment for ectopics of less than 3.5 cm with no fetal heart motion. The effect of methotrexate treatment on future fertility needs more study: fertility may be preserved but recurrent ectopics may be more common.
3. Rhogam. If ectopic or spontaneous abortion is confirmed, remember to give Rh prophylaxis to Rh-negative women.