Validation of ICD-10-CM Diagnosis Codes for Gestational Age at Birth

The International Classification of Diseases Clinical Modification 10th Revision (ICD-CM-10) introduced diagnosis codes for week gestation at delivery (8-42 weeks). Our objective was to assess the validity these codes, which could have major utility in perinatal research and quality improvement. We used linked birth certificate hospitalization discharge data from all live births California during 2016-2019 (N = 1,843,992). Gestational age identified using Z3A.xx ICD-10-CM maternal patient compared with gold standard best obstetric estimate, as recorded on certificate. further assessed sensitivity specificity gestational categories (< 37 weeks, < 32 28 weeks) given are frequently interest. excluded records 20 or >42 weeks if missing (3.9%). 1,771,527 patients had data. When comparing data, mean difference -0.32 days (SD=3.80) R2 value 0.92. 95% observed differences between pairs measurements were -7.14 +7.77 days, 99.3% within +/-14 days. sensitivity, specificity, positive predictive value, negative high three categories, although did decrease earlier category (Table). Week-specific found when estimate introduction implementation 2015 is promising improvement purposes.