Prenatal Screening for Fetal X‐Linked Ichthyosis: A Large Cohort Study Combining Non‐Invasive Prenatal Testing and Maternal Serum Unconjugated Estriol Analysis

Integrating NIPT-based maternal CNV detection with maternal serum uE3 quantification significantly improves the accuracy of prenatal XLI screening. This combined approach is most clinically actionable in a specific scenario: a male fetus presenting with normal ultrasound findings, extremely low maternal uE3, and a positive family history of isolated XLI without comorbidities.