title: A prediction model for viability at the end of the first trimester after a single early pregnancy evaluation.
abstract: OBJECTIVE
  The aim was to develop a new model to predict the outcome at the end of the 1st trimester after a single visit to the early pregnancy unit (EPU).
  
  
  METHODS
  Prospective observational study in the EPU at Nepean Hospital, between November 2006 and February 2009. Data were collected from all women in the 1st trimester of their pregnancy who had a live intrauterine pregnancy (IUP) at the 1st transvaginal ultrasound scan (TVS). 29 historical, clinical and ultrasound end points were recorded. Women were followed until the final diagnosis was established at the end of the 1st trimester: viability or nonviability. A multinomial logistic regression model was developed. The performance of this model was evaluated using receiver operating characteristic (ROC) curves.
  
  
  RESULTS
  Data from 416 pregnancies were included: 92.1% were live beyond the 1st trimester, and 7.9% had miscarried. The most useful prognostic variables for developing the logistic regression model were gestational age by dates, vaginal (PV) bleeding, PV clots, gestational age by TVS, consistency with menstrual dates, mean gestational sac (GS) size, mean yolk sac (YS) size and number of previous caesarean sections. Used retrospectively on 416 women based on 25 imputations, the model gave an AUC of 0.88. Based on cross-validation, the independent predictive power obtained an AUC of 0.78.
  
  
  CONCLUSIONS
  We have developed a new model to predict the outcome of the 1st trimester in women with live IUP at the 1st scan.
authors: Early Pregnancy and Advanced Endosurgery Unit, Acute Gynaecology, Nepean Centre for Perinatal Care, Nepean Clinical School, Nepean Hospital, University of Sydney, Kingswood, Australia.
authors: Jennifer
authors: J
authors: Oates
authors: Ishwari
authors: I
authors: Casikar
authors: Anna
authors: A
authors: Campain
authors: Samuel
authors: S
authors: Müller
authors: Jean
authors: J
authors: Yang
authors: Shannon
authors: S
authors: Reid
authors: George
authors: G
authors: Condous
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D016216:Ultrasonography, Prenatal; D055815:Young Adult