Early detection of pregnancy after IVF and embryo transfer with hyperglycosylated HCG versus Elecsys HCG plus β assay

Research question: Is measurement of hyperglycosylated HCG (hHCG) superior to beta-HCG (HCG+beta) for early pregnancy detection after IVF and embryo transfer? Design: Blood samples were collected on day 4 (+1), 7 (+1) and 11 (+2) after embryo transfer from women aged 18-45 years undergoing first or second fresh or frozen IVF embryo transfer cycles. Biochemical pregnancy was assessed on-site by HCG determination on day 11; clinical pregnancy was assessed by ultrasound on day 21 (+4/-3). Serum hHCG (immunochemiluminometric assay) and HCG+beta (Elecsys (R) HCG+beta assay) concentrations were measured. Performance of hHCG and HCG +beta for predicting pregnancy was evaluated and cut-offs selected. Results: In total, 155 women were enrolled and underwent IVF and embryo transfer. Area under the curve (AUC) (95% CI) on day 4 was not significantly different for hHCG (AUC 0.88; 95% CI 0.83 to 0.94) and HCG+beta (AUC 0.90; 95% CI 0.84 to 0.95), as was predictive performance on day 7 and 11, with higher AUC estimates compared with day 4. Applying cut-offs derived according to Youden's index on day 4 (hHCG, 100 pg/ml; HCG+beta, 1.30 mIU/ml), both biomarkers demonstrated high negative predictive values for ruling out pregnancy (hHCG, 83.8%; HCG+beta, 82.8%) and high positive predictive values for ruling in pregnancy (hHCG, 89.0%; HCG+beta, 84.9%) on day 21. Diagnostic performance improved from day 4 to day 11. Conclusions: Predictive performance for early pregnancy post-IVF embryo transfer of day-5 blastocysts was not significantly different for hHCG and HCG+beta; hHCG superiority over HCG+beta was not shown.

Automated summary

The study aimed to compare the measurement of hHCG and HCG+beta for early pregnancy detection after IVF and embryo transfer. The results showed that the predictive performance of both biomarkers was similar at different time points, and the diagnostic performance improved from day 4 to day 11.