title: Urinary gonadotropin measurements in neonates: a valuable non-invasive method.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Medicine, VU University medical center, VUmc, and Emma Children's Hospital AMC, 1007 MB Amsterdam, The Netherlands. cb.lambalk@vumc.nl
authors.forename: E A M
authors.initials: EA
authors.lastname: Kuijper
authors.forename: E J F
authors.initials: EJ
authors.lastname: Houwink
authors.forename: M M
authors.initials: MM
authors.lastname: van Weissenbruch
authors.forename: H A
authors.initials: HA
authors.lastname: Heij
authors.forename: M A
authors.initials: MA
authors.lastname: Blankenstein
authors.forename: J
authors.initials: J
authors.lastname: Huijser
authors.forename: F
authors.initials: F
authors.lastname: Martens
authors.forename: C B
authors.initials: CB
authors.lastname: Lambalk
mesh_terms: D000328:Adult; D000368:Aged; D001331:Automation; D002624:Chemistry, Clinical / Q000379:methods; D003404:Creatinine / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000096:biosynthesis; D006062:Gonadotropins / Q000097:blood* / Q000652:urine*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D007986:Luteinizing Hormone / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D006062:Gonadotropins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D003404:Creatinine