A 30-year-old woman (gravida G3, para 1) who is approximately 6 weeks pregnant called into the after-hours Ob/Gyn line over the weekend with reported spotting. She stated that she had bright red spotting for 24 hours that has now stopped. She denied any pain, dizziness, gastrointestinal symptoms, change in activity, or trauma. She had a miscarriage at 6 weeks’ gestation 3 months prior and is concerned for another miscarriage. She also denied any history of sexually transmitted infections, drug use, or smoking.
The patient presented on April 24th for examination, 24 hours after the bleeding stopped, at which time human chorionic gonadotropin (hCG) levels were obtained for comparison with previous levels. The patient was sent home, but she was directed to call if bleeding started again or if she experienced any pain. A review of the β-hCG levels is as follows: April 15th, 674 mIU/mL; April 20th, 4934 MIU/mL; and April 24th, 9014 mIU/mL. Progesterone level recorded on April 15th was 15.0 ng/mL (expected first-trimester progesterone range, 11.2-90.0 ng/mL).
The results were discussed with the patient’s obstetrician/gynecologist and were determined to be increasing appropriately. The hCG levels should increase by at least 53% in 48 hours or double in 72 hours (Table). The patient was still concerned for miscarriage and was scheduled for an ultrasound at the hospital that week to confirm the pregnancy.
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The ultrasound was scheduled for 3 days after the last hCG level was taken, and no further spotting was noted. On the morning of the ultrasound, the patient experienced sharp shooting lower pelvic/vaginal pain that went away after a few minutes. She presented for her ultrasound, which did not show any products of conception within the uterus. A transvaginal ultrasound was then performed, which revealed a left ectopic pregnancy with a fetal pole and positive cardiac activity. Free fluid was noted suggesting rupture. The patient was stable and sent immediately for direct admit and scheduled for an emergent laparoscopy.
The patient was taken to the operating room for laparoscopy to remove the ectopic pregnancy and repair the possible rupture. Once visualized, a left cornual ectopic pregnancy was identified and was noted to be bulging from the side of the uterus (Figure). The decision was made to convert to an open laparotomy, which was successful in removing the ectopic pregnancy. The patient was hemodynamically stable during the entire procedure and fully recovered.
Discussion
In a normal pregnancy, following fertilization the blastocyst implants in the endometrial lining of the uterine cavity. Implantation elsewhere is considered an ectopic pregnancy. In the United States, ectopic pregnancies comprise 1% to 2% of all first-trimester pregnancies.1 Ectopic pregnancies account for 6% of all pregnancy-related maternal deaths1; this number has dramatically decreased over the past decades with early urine and serum beta-hCG levels, transvaginal ultrasounds, and early diagnosis through assessment of symptoms by medical providers.
Nearly 95% of ectopic pregnancies are implanted into the fallopian tube.1 The remaining 5% involve a cornual ectopic pregnancy, which is also known as an interstitial ectopic pregnancy.1 In a cornual ectopic pregnancy, the blastocyst implants where the proximal segment of the fallopian tube connects with the muscular wall of the uterus. In this case study, as the embryo grew at the junction of the fallopian tube and uterus, it eroded the tissue, ultimately attaching to the outside of the uterus. An interstitial pregnancy can be difficult to distinguish on ultrasound from an intrauterine pregnancy that is eccentrically placed. The hCG levels will rise appropriately, which in this case caused a delay in diagnosis. Due to delay in diagnosis, rupture occurs in approximately 20% to 50% of cases in this location.2 Although the maternal mortality rate associated with ectopic pregnancies is decreasing, the maternal mortality rate associated with cornual ectopic pregnancies remains at 2.5% because of misdiagnosis of these gestations.2
Conclusion
The classic presentation of delayed menstruation, pain, and vaginal bleeding or spotting is not always representative of miscarriage. Some degree of vaginal bleeding is reported in 60% to 80% of women with ectopic pregnancy prior to rupture.2 Routine prenatal care does not include serial hCG levels or early transvaginal ultrasound assessment. It is important to have a high degree of suspicion for ectopic pregnancy in a woman with painless first-trimester bleeding. Relying on serial hCG levels alone will not identify all ectopic pregnancies. Clinical judgment is key in screening and identifying women with an ectopic pregnancy before rupture occurs.
Amber Murphy, PA-C, works in obstetrics at Beaumont Hospital in Royal Oak, Michigan.
References
- Cunningham F, Leveno KJ, Bloom SL, et al. Ectopic pregnancy. In: Williams Obstetrics. 24th edition. New York, NY: McGraw-Hill; 2013.
- Surette A, Dunham SM. Early pregnancy risks. In: CURRENT Diagnosis & Treatment Obstetrics & Gynecology. 11th edition. New York, NY: McGraw-Hill; 2013.
