Ultrasound Biomarkers Sharpen Noninvasive Diagnosis of ICP and Preeclampsia: New Evidence

Study Design at a Glance

This prospective study enrolled 270 pregnant women: 45 with ICP, 90 with PE (split evenly between mild and severe cases), and 135 healthy controls. Each case of ICP or PE was carefully matched with a control by age and gestational age. The researchers measured liver fat content (UDFF), liver stiffness (Auto pSWE), and conventional clinical/lab markers, then analyzed their ability to discriminate between patient groups.

Key Findings: UDFF and Auto pSWE Reveal Distinct Patterns

ICP vs. Controls: Both UDFF and liver stiffness were elevated in ICP patients, but stiffness (Auto pSWE) had higher diagnostic accuracy for ICP. A cutoff of ~7.5 kPa provided 93% specificity.

PE Severity and Screening: In preeclampsia, both UDFF and stiffness increased with disease severity. However, UDFF outperformed stiffness for detecting and grading PE, especially severe cases (AUC 0.93 for UDFF vs. 0.83 for stiffness). UDFF thresholds of ~6.7% identified severe PE with 77% sensitivity and 97% specificity.

Independent Predictors: Multivariable models confirmed that both UDFF and Auto pSWE were independent predictors for ICP and PE, even when adjusting for BMI and lab values.

Clinical Implications: Why These Findings Matter

UDFF quantifies liver fat by analyzing ultrasound backscatter and attenuation, closely mirroring MRI fat fraction but in a more accessible, real-time format. Auto pSWE measures liver stiffness, reflecting fibrosis and inflammation. Used together, these tools provide a window into both metabolic and structural liver changes associated with pregnancy complications.

For clinicians, this means:

Earlier, more accurate diagnosis of ICP and PE

Improved risk stratification—identifying high-risk pregnancies before complications arise

Noninvasive and repeatable monitoring tools, reducing reliance on blood tests alone

Technical Terms, Simplified

UDFF (Ultrasound-Derived Fat Fraction): A measurement of liver fat using specialized ultrasound techniques.

Auto pSWE (Automated Point Shear-Wave Elastography): An ultrasound method that gauges liver stiffness, often elevated with fibrosis or inflammation.

Limitations and Future Directions

While results are promising, the study was single-center with a modest sample size, and measurements occurred mostly in late pregnancy. Broader, multicenter studies—especially in early gestation—are needed to confirm these findings and standardize protocols.

Conclusion

The combination of UDFF and Auto pSWE offers clinicians powerful, noninvasive tools for detecting and staging ICP and preeclampsia. Integrating these techniques into routine obstetric care could lead to earlier intervention and better outcomes for mothers and infants.

Key Points

UDFF and liver stiffness both increase in ICP and preeclampsia, but each marker offers unique diagnostic value.

UDFF is particularly effective for identifying and grading preeclampsia severity.

Auto pSWE provides high specificity for diagnosing ICP.

Quantitative ultrasound metrics supplement, but do not replace, clinical and laboratory assessments.

Broader validation is needed before routine clinical adoption, but these tools show strong potential for enhancing pregnancy care.

Citation:

Niu K., Ye J., Zhang W. et al. Ultrasound-derived fat fraction and automated point shear-wave elastography in diagnosing intrahepatic cholestasis of pregnancy and preeclampsia. BMC Pregnancy Childbirth. 2026; [in press]. https://doi.org/10.1186/s12884-026-09655-4