Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Townsville, Queensland, Australia.
Reprod Domest Anim. 2022 Jun;57(6):635-642. doi: 10.1111/rda.14104. Epub 2022 Mar 7.
The prediction of time to onset of parturition in a preparturient bitch is of great clinical value, particularly for bitches at high risk of dystocia and those lacking relevant clinical data from the time of breeding. In a previous study, four cut-offs for plasma progesterone levels, measured by radioimmunoassay, were shown to be useful for predicting the likelihood of a bitch entering stage one of parturition within defined time intervals. The first aim of the current study was to evaluate these cut-offs in a clinical setting, using serum progesterone samples drawn from preparturient bitches 12-hourly instead of 6-hourly and assessed using chemiluminescence immunoassay. Furthermore, the use of 13,14-dihydro-15-keto-prostaglandin F (PGFM), a metabolite of prostaglandin F , in predicting the time to onset of parturition was evaluated. Forty bitches carrying two or more foetuses were admitted to a specialist veterinary reproduction hospital 53 d after the onset of cytological dioestrus when that date was known, or 57 d after the last mating. Vaginal speculum examinations were performed every 6 hr until cervical dilatation was visualized (time of cervical dilatation; TCD). Serum samples were collected at 08h00 and 18h00 daily until TCD. All bitches underwent elective caesarean section at TCD. Results of this study show that approximately 5% and 10% of preparturient bitches will reach TCD within 12 hr despite a serum progesterone level of at least 15.8 nmol/L and 8.7 nmol/L respectively. In addition, there is a 95% probability that a preparturient bitch will reach TCD within 48 hr if her serum progesterone level is below 8.7 nmol/L, and a 91% probability of her reaching TCD within 24 hr if her serum progesterone level is below 3.18 nmol/L. Approximately 90% of bitches that demonstrate a 20% increase in PGFM over a 12-hr period are likely to be within 36 hr of TCD. These results provide useful benchmarks for the management of canine parturition.
预测即将分娩的产前期母犬的分娩时间具有重要的临床价值，尤其是对于那些难产风险较高的母犬，以及那些在配种时缺乏相关临床数据的母犬。在之前的一项研究中，通过放射免疫分析测量的四种血浆孕酮水平的截断值被证明可用于预测母犬在特定时间间隔内进入分娩第一阶段的可能性。本研究的首要目标是在临床环境中评估这些截断值，使用 12 小时而非 6 小时采集的产前母犬的血清孕酮样本，并使用化学发光免疫分析法进行评估。此外，还评估了前列腺素 F 的代谢产物 13,14-二氢-15-酮-前列腺素 F（PGFM）在预测分娩时间方面的作用。当已知细胞学发情期开始后 53 天时（如果已知该日期）或最后一次交配后 57 天，将携带两只或更多胎儿的 40 只母犬收治到一家专门的兽医繁殖医院。当观察到宫颈扩张时（宫颈扩张时间；TCD），每 6 小时进行阴道窥镜检查。在 TCD 之前，每天 08h00 和 18h00 采集血清样本。所有母犬均在 TCD 时行选择性剖宫产。本研究的结果表明，尽管血清孕酮水平至少为 15.8 nmol/L 和 8.7 nmol/L，但仍有约 5%和 10%的产前期母犬会在 12 小时内达到 TCD。此外，如果血清孕酮水平低于 8.7 nmol/L，则 95%的产前期母犬将在 48 小时内达到 TCD，如果血清孕酮水平低于 3.18 nmol/L，则 91%的母犬将在 24 小时内达到 TCD。如果在 12 小时内 PGFM 增加 20%，则约 90%的母犬可能在 36 小时内达到 TCD。这些结果为犬类分娩管理提供了有用的基准。
