Relationship of Beta-Human Chorionic Gonadotropin to EctopicPregnancy Detection and Size

Introduction: Ectopic pregnancies are a significant cause of morbidity and mortality in thefirst trimesterof pregnancy. Hospital protocols requiring a specific beta-human chorionic gonadotropin (beta-hCG) level toqualify for diagnostic testing (pelvic ultrasound) can delay diagnosis and treatment. In this study wesought to determine the relationship between beta-hCG level and the size of ectopic pregnancy withassociated outcomes. Methods: We performed a retrospective case review of patients diagnosed with ectopic pregnancy in anurban, academic emergency department specializing in obstetrical care, from January 1,2015-December 31, 2017. Variables extracted included presentation, treatment, adverse outcomes,and rates of rupture. Results: We identified 519 unique ectopic pregnancies. Of those ectopic pregnancies, 22.9% presentedwith evidence of rupture on ultrasound, and 14.4% showed evidence of hemodynamic instability (pulse>100 beats per minute; systolic blood pressure<90 millimeters of mercury; or evidence of significantblood loss) on presentation. Medical management outcomes were as follows: of 177 patients whoreceived single-dose methotrexate, 14.7% failed medical management and required surgicalintervention; of 46 who received multi-dose methotrexate, 36.9% failed medical management andrequired surgical intervention. Ultimately, 55.7% of patients required operative management of theirectopic pregnancy. Mean beta-hCG level at initial presentation was 7,096 milli-international units permilliliter (mIU/mL) (SD 88,872 mIU/mL) with a median of 1,289 mIU/mL; 50.4% of ectopic pregnanciespresented with beta-hCG levels less than the standard discriminatory zone of 1,500 mIU/mL. Additionally,44% of the patients who presented with evidence of rupture had beta-hCG levels less than 1,500 mIU/mL.Comparison of size of ectopic pregnancy (based on maximum dimension in millimeters) to beta-hCG levelsrevealed a very weak correlation (r=0.144,P<.001), and detection of ectopic pregnancies byultrasound was independent of beta-hCG levels. Conclusion: Levels of beta-hCG do not correlate with the presence or size of an ectopic pregnancy,indicating need for diagnostic imaging regardless of beta-hCG level in patients with clinical suspicion forectopic pregnancy. Almost one-sixth of patients presented with evidence of hemodynamic instability,and approximately one quarter of patients presented with evidence of rupture requiring emergentoperative management. Ultimately, more than half of patients required an operative procedure todefinitively manage their ectopic pregnancy. [West J Emerg Med. 2024;25(3)431-435.]