title: Human chorionic gonadotropin and plasma protein-A in alpha0-thalassemia pregnancies.
abstract: OBJECTIVE
  Maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) have been used effectively in the screening of Down syndrome in the first trimester. In this study, we aim to measure the value of first-trimester maternal serum free beta-hCG and PAPP-A as predictors of homozygous alpha0-thalassemia-affected pregnancies.
  
  
  METHODS
  Free beta-hCG and PAPP-A concentrations were measured in stored maternal serum samples obtained at 12 weeks of gestation from 22 women with fetuses affected by homozygous alpha0-thalassemia and from 436 controls matched for maternal age, ethnicity, and weight, as well as gestation at blood sampling.
  
  
  RESULTS
  Maternal serum concentration of free beta-hCG was significantly increased in women with pregnancies affected by homozygous alpha0-thalassemia than in controls (P = .001). Concentrations of PAPP-A did not differ between the cases affected by homozygous alpha0-thalassemia and the controls (P = .652).
  
  
  CONCLUSIONS
  Pregnancies affected by homozygous alpha0-thalassemia are associated with increased maternal serum free beta-hCG at 11-14 weeks of gestation. This serum analyte alone may not be clinically useful as a predictor of pregnancies affected by homozygous alpha0-thalassemia. However, the absence of ultrasound features of fetal anemia and hydropic changes, together with normal maternal serum free beta-hCG and PAPP-A in the first trimester, will be reassuring signs of normality for fetuses at risk of homozygous alpha0-thalassemia and, hence, enable women to avoid invasive tests in unaffected pregnancies.
authors.affiliation: Department of Obstetrics and Gynecology, the University of Hong Kong. cytong@hkucc.hku.hk
authors.forename: Charas Yeu Theng
authors.initials: CY
authors.lastname: Ong
authors.forename: Chin Peng
authors.initials: CP
authors.lastname: Lee
authors.forename: Kwok Yin
authors.initials: KY
authors.lastname: Leung
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lau
authors.forename: Mary Hoi Yin
authors.initials: MH
authors.lastname: Tang
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D016022:Case-Control Studies; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000032:analysis / Q000097:blood*; D005189:False Positive Reactions; D005260:Female; D005315:Fetal Diseases / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D006720:Homozygote; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000097:blood / Q000175:diagnosis*; D011261:Pregnancy Trimester, First / Q000097:blood; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis*; D011296:Prenatal Diagnosis / Q000379:methods*; D012680:Sensitivity and Specificity; D017085:alpha-Thalassemia / Q000097:blood / Q000175:diagnosis* / Q000235:genetics
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A