Makhijani R, et al. - This study strived to formulate an easy-to-use risk stratification tool to determine which patients with pregnancies of unknown location (PULs) were at highest risk for ectopic pregnancies (EP). The developed model could accurately speculate the risk of EP. It was noted that the combination of initial b-hCG with b-hCG ratio was the most highly predictive of EP.

Methods

• The design of this paper was a retrospective review.
• An appraisal was performed of the electronic medical records of 800 patients with PULs between 9/2008-10/2016 at a university-based hospital.
• Risk factors, initial b-hCG, b-hCG ratio aided in formulating a generalized additive model (GAM), which assisted in the measurement of an estimated EP risk score.
• Receiver operator curve (ROC) analysis was also carried out.
• The included candidates were those with at least two beta values estimated between 36 to 72 hours apart.
• The excluded subjects were those with molar pregnancies as well as ruptured EPs who had surgery before second b-hCG was measured.

Results

• 398 patients were recruited.
• Forty were diagnosed with EP (10.1%), 168 with intrauterine pregnancy (42.21%) and 190 with spontaneous abortion (47.7%).
• 7 subjects reported a history of PID (1.8%), 34 had a history of STD (8.5%) and 224 were parous (56.3%).
• For the prediction of EP, the area under ROC curve for the GAM model was 0.863 for initial b-hCG and b-hCG ratio, 0.723 for initial b-hCG alone and 0.843 for b-hCG ratio alone.
• A marked rise was noted in the tendency of EP, via a history of prior ectopic and PID.
• Parity was protective.