Maternal urine β-core hCG fragment level and small for gestational age neonates

Ray Bahado-Singh, Utku Oz, Divina Flores, Chaur Dong Hsu, Giancarlo Mari, Laurence Cole

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Objective: To determine whether second-trimester urine β-core fragments of hCG predict small for gestational age (SGA) neonates. Methods: Spot urine β-core levels were measured in 733 nonhypertensive women with singleton pregnancies who presented for amniocentesis and had karyotypically normal fetuses. The β-core level was standardized to urine creatinine and expressed as multiples of the median. The area under a receiver operating characteristics curve was used to determine the screening efficiency of the urine analyte for prediction of small for gestational age (SGA) births. In a subgroup of cases, serum markers (alpha-fetoprotein [AFP], hCG, and unconjugated estriol) were compared using stepwise regression analysis to urine β-core fragment for SGA prediction. Results: There were 23 (3.0%) SGA neonates. The mean ± standard deviation (SD) gestation at urine collection was 16.4 ± 1.3 weeks and collection to delivery interval was 23.0 ± 2.2 weeks. Mean β-core (± SD) fragment levels were significantly higher in those who later had SGA infants compared with appropriately grown infants (2982.8 ng/mg creatinine versus 1447.4 ng/mg creatinine, P <. 001). Stepwise logistic regression found that urine β-core fragment and serum AFP were the only significant predictors of SGA, with statistically significant χ2 values (P <. 001 and P =. 038, respectively). The urine analyte was significantly superior. Second-trimester urine β-core fragment had a 78.3% sensitivity and 70% specificity for SGA prediction. Exclusion of preeclamptic cases resulted in a sensitivity of 84.2% and a specificity of 71.2%. Conclusion: Second-trimester elevated maternal urine β-core fragment of hCG predicted SGA infants, and was superior to other serum analytes in that prediction. Copyright (C) 2000 The American College of Obstetricians and Gynecologists.

Original languageEnglish (US)
Pages (from-to)662-666
Number of pages5
JournalObstetrics and gynecology
Issue number5
StatePublished - May 2000
Externally publishedYes

ASJC Scopus subject areas

  • Obstetrics and Gynecology


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