title: Prediction of Parturition Time in Queens using Radiography and Ultrasonography.
abstract: This study investigated the prediction of parturition in queens, as well as the effects of the queens' age and weight and the litter size on the accuracy of the prediction. A prospective study was performed in 24 purebred queens of 11 different breeds, all in normal body condition, using radiographic and ultrasonographic measurements of foetal femoral length (FL) and biparietal diameter (BPD) of fœtal skull that apply to different breeds. Pregnant queens with aborted or malformed foetuses were excluded. The examinations were performed up to three times during the second half of pregnancy; litter size was obtained with radiography, and FL and BPD measurements were taken of each foetus using both radiography and ultrasonography. The maximal FL and the transversal BPD were recorded for each foetus. Radiography showed the number of foetuses accurately but did not allow accurate prediction of time of parturition. However, ultrasonography did establish the best predictive model according to the data with the FL. This model corresponded to the formula Y = 37.864 - 0.193 × FL + 1.227 × W - 0.615 × LS - 0.832 × A using the FL (10(-1)  mm), litter size (LS, number of foetuses per queen) and maternal parameters (weight (W, kg) and age (A, years)). Time to parturition correlated positively with the queen's weight and negatively with her age (P < 0.01). The ultrasonographic FL associated with pregnancy and maternal factors appeared to be an accurate model to predict parturition.
authors.affiliation: Department of Veterinary Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Gatel
authors.affiliation: Referral Center in Veterinary Diagnostic, Imaging and Neurology, AZURVET, Hippodrome 2 Bd Kennedy, Cagnes sur Mer, 06800, France.
authors.forename: D
authors.initials: D
authors.lastname: Rault
authors.affiliation: VetAgro-Sup - Campus Vétérinaire de Lyon, VetAgro-Sup, Avenue Bourgelat 1, Marcy l'Etoile, 69280, France.|UR 346 Epidemiologie Animale, INRA, Saint Genès Champanelle, 63122, France.
authors.forename: K
authors.initials: K
authors.lastname: Chalvet-Monfray
authors.affiliation: Department of Veterinary Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Saunders
authors.affiliation: VetAgro-Sup - Campus Vétérinaire de Lyon, VetAgro-Sup, Avenue Bourgelat 1, Marcy l'Etoile, 69280, France.
authors.forename: S
authors.initials: S
authors.lastname: Buff
mesh_terms: D000367:Age Factors; D000818:Animals; D001827:Body Height; D001835:Body Weight; D002113:Calcification, Physiologic; D002415:Cats / Q000502:physiology*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000196:embryology; D005333:Fetus / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D007745:Labor Onset / Q000502:physiology*; D016014:Linear Models; D008098:Litter Size; D010294:Parietal Bone / Q000000981:diagnostic imaging / Q000196:embryology; D011237:Predictive Value of Tests; D011247:Pregnancy; D016216:Ultrasonography, Prenatal / Q000592:standards / Q000662:veterinary*