Are foetal ultrasonographic and maternal blood progesterone measurements near parturition reliable predictors of the time of birth in the domestic cat?

Abstract

In cats, accuracy of parturition day prediction by ultrasonographic measurement of foetal structures is decreasing towards the end of gestation. Foetal measurements during the last days of pregnancy are scarce. We determined foetal biparietal, abdominal and eye diameter (BPD, AD and ED, respectively) by ultrasonography as well as maternal blood progesterone (P4) within five days of delivery to predict parturition date and calculate accuracy of prediction. Foetal BPD at birth was compared with newborn kitten head diameter (HD). Kitten HD, crown-rump length (CRL) and body weight were compared by breed and gender. Ultrasonography measurements were carried out on the day of parturition in 14 queens, and on days 62-63 after the first mating and repeated 24-72 hr later in ten other cats. Accuracy of parturition day prediction using BPD and AD was determined based on the equations of Beccaglia et al. (2008) Veterinary Research Communications, 32(Suppl 1), S99 and Garcia Mitacek et al. (2015) Theriogenology, 84, 1131. Progesterone was measured at the time of presentation and repeated 24-72 hr later if parturition did not occur. Data were analysed with linear regression, t test, Mann-Whitney U test, one-way anova and Kruskal-Wallis test. There was a moderate relationship between BPD, days before birth (DBB) and litter size. AD and DBB had a low agreement, and ED was not associated with DBB. BPD at birth was significantly related to HD. The accuracy of parturition day prediction using BPD and AD was 27-53% and 17-35%, respectively. Kitten HD was associated with body weight, and both were inversely related to litter size. Newborn biometric measurements differed by breed but not by gender. Progesterone decreased towards parturition and reached 3.18 ± 1.68 ng/ml on the day of delivery. In conclusion, close to birth, the combination of foetal ultrasonography and maternal blood P4 rather than each as a sole predictor of parturition is recommended.

Development of specific fetometric formulas of ICC and BP for predicting the parturition date in Maine Coon queens

“…In their study, the mean length of pregnancy in Maine Coon was 65.4 ± 2.4 days comparing to results of Sparkes et al () where the mean gestation length was 65.5 days and our own results of 66.3 days (Musters et al, ; Sparkes et al, ). The presence of breed‐dependent variations in gestation length in large cat breeds like Maine Coon, comparing to other cats were suggested by different authors (Gatel et al, ; Keiser et al, ; Musters et al, ).…”

“…This study proposes novel breed‐specific ICC and BP ultrasonographic formulas for Maine Coon cats. It should also be noted that the effect of breed on the accuracy of ultrasonographic biometry has not been widely investigated to date, mainly due to the small number and considerable variations in the analysed groups of queens (Beccaglia et al, ; Davidson & Baker, ; Garcia Mitacek et al, ; Keiser et al, ; Zambelli & Prati, ). The model developed by Gatel, Rault, Chalvet‐Monfray, Saunders, and Buff () for predicting the delivery date based on various maternal and pregnancy parameters (foetal femur length, queen's weight before pregnancy, litter size and queen's age) produced promising results (Gatel et al, ).…”

“…This study proposes novel breed-specific ICC and BP ultrasonographic formulas for Maine Coon cats. It should also be noted that the effect of breed on the accuracy of ultrasonographic biometry has not been widely investigated to date, mainly due to the small number and considerable variations in the analysed groups of queens (Beccaglia et al, 2008;Davidson & Baker, 2009;Garcia Mitacek et al, 2015; Keiser et al, 2017;Zambelli & Prati, 2006). The F I G U R E 1 Relationship between inner chorionic cavity diameter (ICC) and the number of days before parturition established using regression analysis F I G U R E 2 Relationship between biparietal diameter (BP) and the number of days before parturition established using regression analysis cies with small litters (Musters et al, 2011).…”

“…Accurate prediction of the parturition date in queens enables prompt assistance and adequate treatment in physiological deliveries or in prolonged gestation and high‐risk pregnancies (Keiser, Reichler, & Balogh, ). Due‐date predictions are also mandatory for planning a caesarean section (Michel, Spörri, Ohlerth, & Reichler, ).…”

“…To date, parturition dates in queens have been predicted ultrasonographically by some studies, but often on small number of cats (Beccaglia et al, ; Beccaglia & Luvoni, ; Garcia Mitacek et al, ; Keiser et al, ). In our preliminary study of Maine Coons, the predicted delivery date was calculated with the use of two universal equations (Beccaglia et al, ; Beccaglia & Luvoni, ).…”