title: Highly specific and sensitive rise in Days 14-17 pro-alphaC inhibin with clinical pregnancy after frozen embryo transfer with ovulatory cycles.
abstract: BACKGROUND
  Pro-alphaC inhibins are luteal derived analytes peaking in the maternal serum as early as Day 16 after conception. We set out to verify a previous post hoc analysis which suggested that pro-alphaC levels measured this early are extremely sensitive in predicting clinical pregnancy success after unstimulated IVF with ovulatory cycles.
  
  
  METHODS
  Prospective observational study of 246 women undergoing frozen embryo transfer with ovulatory cycles. Serum pro-alphaC and beta-HCG levels at 14-17 days after conception were measured by enzyme-linked immunosorbent assay and grouped according to whether a clinical pregnancy occurred (demonstrable cardiac activity at > or =6 weeks' gestation).
  
  
  RESULTS
  Of 34 (13.8%) women who achieved a clinical pregnancy, median (25th-75th centile) Days 14-17 pro-alphaC levels were 995 pg/ml (758-1463), 6- to 7-fold higher than levels observed in the remainder who did not fall pregnant (112.8 pg/ml (104-121); P < 0.0001). At a fixed 95% specificity, pro-alphaC was 100% sensitive in predicting clinical pregnancy. The best specificities achieved at 100% sensitivity were; 94.8% for pro-alphaC, 96.7% for beta-HCG and 98.1% when both analytes were combined.
  
  
  CONCLUSIONS
  Clinical pregnancy is always associated with a release of luteal derived pro-alphaC 14-17 days after conception. Pro-alphaC may play a possible biological role and be a useful clinical biomarker of luteal health.
authors.affiliation: Centre for Women's Health Research, Department of Obstetrics and Gynaecology, Monash Medical Centre, Monash University, 246 Clayton Road, Clayton 3168, Victoria, Australia. stephentong1@gmail.com
authors.forename: S
authors.initials: S
authors.lastname: Tong
authors.forename: L
authors.initials: L
authors.lastname: Rombauts
authors.forename: J
authors.initials: J
authors.lastname: Onwude
authors.forename: B
authors.initials: B
authors.lastname: Marjono
authors.forename: E M
authors.initials: EM
authors.lastname: Wallace
mesh_terms: D000328:Adult; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D005615:Freezing; D006801:Humans; D007265:Inhibins / Q000097:blood*; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D011498:Protein Precursors; C095971:inhibin-alpha subunit precursor; D007265:Inhibins