Transvaginal Ultrasound Compared with Serum β-hCG Level for Diagnosis of Ectopic Pregnancy in Symptomatic Patients

Abstract

Abstract Background: Ultrasonography (US) is the most important imaging modality in detecting both intrauterine and ectopic pregnancies. This study aimed to compare serum β-hCG level with Transvaginal Ultrasound in symptomatic patients with ectopic pregnancy. Materials and Methods: A total of 210 patients with definite diagnosis of ectopic pregnancy were enrolled prospectively. All patients underwent transvaginal US by an experienced radiologist who was blind to the final status of the patient. Serum levels of β-hCG and the time gap between US examination and last menstrual period (LMP) were compared between patients with positive and negative US findings. Results: US were positive in 194 patients (92.4%) and negative in the remaining 16 patients (7.6%). The two groups were similar in terms of age (median, 31 years vs. 30.5 years, respectively; p=0.57). Both the median time gap between US and LMP (median, 43 days vs. 34 days, p=0.03) and serum level of β-hCG (median, 1027 mIU/ml vs. 172.5 mIU/ml, p<0.001) were significantly higher in patients with positive US findings. Both differences were independent of each other in multivariate analysis. The best discriminative zone was set at a serum β-hCG level of 326 mIU/ml with a sensitivity and specificity of 86.6% and 87.5%, respectively. Conclusion: According to our findings, both the median serum level of β-hCG and time gap between US and LMP in patients with missed diagnosis of ectopic pregnancy were significantly lower in comparison with correct diagnosis and proposed discriminative zone for serum level of β-hCG in our study is different from the previous studies though further studies are recommended especially in symptomatic patients with suspected ectopic pregnancy.

Keywords

• Ectopic pregnancy
• hCG discriminatory zone
• Human chorionic gonadotropin
• Transvaginal ultrasound