title: Comparison of the accuracy of two ultrasonographic measurements in predicting the parturition date in the bitch.
abstract: OBJECTIVE
  To compare the accuracy of two ultrasonographic measurements, inner chorionic cavity diameter and biparietal diameter, for the prediction of parturition date in small and medium size bitches. The effects of litter size and fetal sex ratio on the accuracy of the prediction were also investigated.
  
  
  METHODS
  Ultrasonographic examinations were performed on pregnant bitches and, depending on the stage of pregnancy, the inner chorionic cavity diameter and biparietal diameter were measured. The mean value of the data of each structure was calculated and the predicted day of parturition was obtained by the application of equations derived from growth curves we previously developed for different size bitches.
  
  
  RESULTS
  The parturition term was predicted with similar accuracy during early gestation, by the measurement of inner chorionic cavity diameter, as well as during late gestation, by the measurement of biparietal diameter. Litter size affected only biparietal diameter accuracy, whereas fetal sex ratio did not influence the estimation of the day of parturition.
  
  
  CONCLUSIONS
  Inner chorionic cavity diameter and biparietal diameter were equally reliable parameters in obtaining a reasonably accurate prediction of parturition date at any gestational period at which a bitch is examined.
authors.affiliation: Department of Veterinary Clinical Sciences-Obstetrics and Gynaecology, University of Milan, Via Celoria 10, 20133 Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Beccaglia
authors.forename: G C
authors.initials: GC
authors.lastname: Luvoni
mesh_terms: D000818:Animals; D002823:Chorion / Q000000981:diagnostic imaging*; D004285:Dogs; D005260:Female; D036801:Parturition; D011237:Predictive Value of Tests; D011247:Pregnancy; D011270:Pregnancy, Animal; D016216:Ultrasonography, Prenatal / Q000662:veterinary*