Urinary gonadotropin measurements in neonates: a valuable non-invasive method.

BACKGROUND To measure low neonatal gonadotropin levels, a sensitive non-invasive method is optimal. The aim of the current study was to validate the Architect i2000SR, an automated immunoassay analyser for the measurement of gonadotropins in unextracted neonatal urine samples against serum gonadotropin levels as a gold standard. METHODS Blood and urine were sampled from 30 approximately six-week-old male and female neonates undergoing elective paediatric surgery. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured and the urine results were corrected for creatinine. RESULTS The agreement between neonatal serum and urinary FSH was 0.904 (3-5 h between samples) and 0.704 (18-20 h). For LH, the correlation coefficients were 0.785 and 0.507, respectively. CONCLUSION We conclude that gonadotropins can be reliably measured using the Architect on randomly voided, non-extracted urine samples collected from neonates by an adhesive device. Urinary gonadotropin levels are a proper reflection of the serum levels.