title: Validation of serum progesterone <35nmol/L as a predictor of miscarriage among women with threatened miscarriage.
abstract: Our recent paper, based on a pilot cohort of 119 women, showed that serum progesterone <35 nmol/L was prognostic of spontaneous miscarriage by 16 weeks in women with threatened miscarriage in early pregnancy. Using a larger cohort of women from the same setting (validation cohort), we aim to assess the validity of serum progesterone <35 nmol/L with the outcome of spontaneous miscarriage by 16 weeks.
  
  
  
  In a prospective cohort study, 360 pregnant women presenting with threatened miscarriage between gestation weeks 6-10 at a tertiary hospital emergency unit for women in Singapore were recruited for this study. The main outcome measure measured is spontaneous miscarriage prior to week 16 of gestation. Area under the ROC curve (AUC) and test characteristics (sensitivity, specificity, positive and negative predictive value) at a serum progesterone cutpoint of <35 nmol/L for predicting high and low risk of spontaneous miscarriage by 16 weeks were compared between the Pilot and Validation cohorts.
  
  
  
  Test characteristics and AUC values using serum progesterone <35 nmol/L in the validation cohort were not significantly different from those in the Pilot cohort, demonstrating excellent accuracy and reproducibility of the proposed serum progesterone cut-off level.
  
  
  
  The cut-off value for serum progesterone (35 nmol/L) demonstrated clinical relevance and allow clinicians to stratify patients into high and low risk groups for spontaneous miscarriage.
authors.affiliation: Duke-National University of Singapore Medical School, 8 College Road, Singapore, 169857, Singapore. lekszemin@gmail.com.
authors.forename: Sze Min
authors.initials: SM
authors.lastname: Lek
authors.affiliation: Department of Obstetrics and Gynecology, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
authors.forename: Chee Wai
authors.initials: CW
authors.lastname: Ku
authors.affiliation: Duke-National University of Singapore Medical School, 8 College Road, Singapore, 169857, Singapore.
authors.forename: John C
authors.initials: JC
authors.lastname: Allen
authors.affiliation: Duke-National University of Singapore Medical School, 8 College Road, Singapore, 169857, Singapore.
authors.forename: Rahul
authors.initials: R
authors.lastname: Malhotra
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 50 Nanyang Ave, Singapore, 639798, Singapore.|Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Drive, Proteos, Singapore, 138673, Singapore.
authors.forename: Nguan Soon
authors.initials: NS
authors.lastname: Tan
authors.affiliation: Duke-National University of Singapore Medical School, 8 College Road, Singapore, 169857, Singapore.
authors.forename: Truls
authors.initials: T
authors.lastname: Østbye
authors.affiliation: Duke-National University of Singapore Medical School, 8 College Road, Singapore, 169857, Singapore.|Department of Obstetrics and Gynecology, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
authors.forename: Thiam Chye
authors.initials: TC
authors.lastname: Tan
mesh_terms: D000022:Abortion, Spontaneous / Q000097:blood* / Q000175:diagnosis; D000033:Abortion, Threatened / Q000097:blood*; D000328:Adult; D019540:Area Under Curve; D015331:Cohort Studies; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D009419:Nerve Tissue Proteins; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011374:Progesterone / Q000097:blood*; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D018570:Risk Assessment; D055815:Young Adult
chemical_list: D009419:Nerve Tissue Proteins; C522731:RUFY3 protein, rat; D011374:Progesterone
keywords: Cut-off level; Miscarriage; Predictive; Progesterone