Similar but different: A comparison of rare site ectopic pregnancies

Objectives: A comparative examination of the clinical, laboratory, ultrasound findings, and operative characteristics of rare site located ectopic pregnancies. Methods: Retrospective analysis of all department cases of rare site located ectopic pregnancies diagnosed and treated from December 2006 to December 2019. Results: Thirty rare ectopic pregnancies were identified. Of these, 11 were ovarian, 10 were interstitial and 9 were tubal stump. The patients treated for ovarian pregnancy had significantly lower human chorionic gonadotropin (hCG) levels than patients treated for interstitial or stump pregnancies (2025 ± 1105 mIU/ml, 18,424 ± 2579 mIU/ml and 11,204 ± 9221 mIU/ml, respectively, p = 0.003). The main presenting symptom in patients with an ovarian pregnancy was abdominal pain (90.9%, 60.0% and 44.4%, respectively, p = 0.031). Signs of abdominal peritoneal irritation (i.e., rebound tenderness and guarding) were more frequent upon physical examination in patients with an ovarian pregnancy (72.2%, 30.0% and 22.2%, respectively, p = 0.044) who also exhibited the highest rates of syncope and hypovolemic shock upon admission compared to patients with an interstitial or stump pregnancy (54.5%, 10.0% and 11.1%, respectively, p = 0.031). Ovarian pregnancies were associated with the lowest sonographic detection rates (9.1%, 80.0% and 100%, respectively, p = 0.0001) and with free fluid in the pouch of Douglas (72.7%, 20.0% and 22.2%, respectively, p = 0.02). Ovarian pregnancies experienced the highest rupture rate during surgery compared to interstitial or stump pregnancies (66.9%, 16.7% and 44.4%, respectively, p = 0.028), had a significantly higher estimated blood loss (1081 ± 647 ml, 760 ± 597 ml and 343 ± 318 ml, respectively, p = 0.003) and required blood transfusions in the perioperative period (63.6%, 20.0% and 11.1%, respectively, p = 0.025) significantly more often. Conclusions: Ovarian pregnancy remains the most challenging diagnosis compared to interstitial and tubal stump ectopic's. Health care providers should recognize these rare site ectopic pregnancies and to handle these gynecological emergencies promptly.