title: Second trimester maternal serum hCG level in an Asian population: normal reference values by ultrasound dating.
abstract: OBJECTIVE
  To establish normative data of maternal serum chorionic gonadotropin (hCG) during the second trimester in an Asian population.
  
  
  METHODS
  We measured the maternal serum hCG levels in 17,955 normal singleton pregnancies between 15 and 21 weeks of gestation. The gestation age was estimated by measurement of fetal biparietal distance (BPD) in all cases. Median values of hCG at various gestational weeks were calculated and the values of hCG were converted to multiple of median (MoM). The incidences of low MoM value and high MoM value were also calculated.
  
  
  RESULTS
  The mean and median values of hCG were 57,153 mIU/ml and 50,120 mIU/ml, respectively, at 15 weeks of gestation and then decreased to 30,898 mIU/ml and 26,226 mIU/ml, respectively, at 21 weeks. We found 8.6% and 9.4% of normal singleton pregnancies have hCG MoM values >2.0 MoM and <0.5 MoM, respectively.
  
  
  CONCLUSIONS
  Our report provides a normal reference data of second trimester maternal hCG levels by ultrasound dating in an Asian population.
authors.affiliation: Department of Obstetrics and Gynecology, Taiwan Adventist Hospital, Taipei.
authors.forename: H J
authors.initials: HJ
authors.lastname: Jou
authors.forename: M K
authors.initials: MK
authors.lastname: Shyu
authors.forename: J C
authors.initials: JC
authors.lastname: Shih
authors.forename: M Y
authors.initials: MY
authors.lastname: Chang
authors.forename: C C
authors.initials: CC
authors.lastname: Lim
authors.forename: C Y
authors.initials: CY
authors.lastname: Tzeng
authors.forename: S M
authors.initials: SM
authors.lastname: Chen
authors.forename: F J
authors.initials: FJ
authors.lastname: Hsieh
mesh_terms: D006063:Chorionic Gonadotropin / Q000097:blood*; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012016:Reference Values; D016216:Ultrasonography, Prenatal
chemical_list: D006063:Chorionic Gonadotropin