Detection rate of quadruple-marker screening determined by clinical follow-up and registry data in the statewide California program, July 2007 to February 2009.

OBJECTIVE

To evaluate the efficiency of California's quadruple-marker screening program and construct receiver-operating characteristic (ROC) curves.

METHODS

This study included the screening records of 552 941 women during July 2007 to February 2009. The screen-positive women received clinical follow-up services at state-approved centers. We used the California Chromosome Defect Registry which includes clinical, laboratory, and demographic data from the prenatal diagnostic centers, cytogenetic laboratories, hospitals, and prenatal care providers. Risk calculations, screen-positive rates (SPRs), detection rates (DRs) for chromosomal abnormalities, and 95% confidence intervals (95% CIs) were determined. ROC curves comparing the quadruple-marker to triple-marker screening were constructed.

RESULTS

The DR and SPR for trisomy 21 (N = 827) during the quadruple-marker time period were 75.7% (95% CI 72.8-78.6%) and 3.75% (95% CI 3.70-3.80%) compared with 77.4% (95% CI 75.0-79.7%) and 5.4% during the triple-marker phase. The DRs were 78.2% (95% CI 75.0-81.4%) with ultrasound dating and 66.9% (95% CI 59.7-74.0%) for last-menstrual-period-dated pregnancies. For trisomy 18, triploidy, and trisomy 13, the DRs were 84.3, 95.7, and 43.5%, respectively.

CONCLUSIONS

The DR for trisomy 21 in California's statewide quadruple-marker screening is very similar to the Program's previously reported DR using triple-marker screening. However, this was achieved at a lower SPR, demonstrating improved screening performance.