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Delivery is not easily predictable in horses and the consequences of dystocia can be serious for both the mare and foal. An induction protocol with low doses of oxytocin has been reported as a safe procedure. This study investigates the effect of induced delivery on at-term mares’ sympathetic-vagal balance. Fourteen mares were included and divided into two groups, one subjected to spontaneous delivery (SD), and one to induced delivery (ID). In both groups, an ECG was recorded using an elastic belt with integrated smart textile electrodes. The recording started before the delivery (Basal), continued close to delivery (Pre-delivery) and during delivery (Delivery), and ended after parturition (Placental expulsion). From the ECGs, Heart Rate Variability (HRV) parameters relating to time and frequency domains and non-linear analysis were extrapolated. The HRV analysis was performed both within the same group (IntraGA) and between the two groups (InterGA). In the present study, spontaneous and induced delivery did not appear to differ in autonomic nervous system functioning. In IntraGA analysis, both for SD and ID mares, delivery and placental expulsion periods were parasympathetic dominated since vagal-related HRV parameters increased. Moreover, no differences were found in InterGA comparison between SD and ID mares, except for the pre-delivery period of ID mares, during which both branches of the autonomic nervous system were activated. These results are in line with the literature on parasympathetic dominance during parturition and no change in Heart Rate Variability following exogenous oxytocin administration in parturient mares.

马的分娩过程难以精准预判，难产对母马与幼驹均可能造成严重不良后果。已有研究报道低剂量催产素诱导分娩方案为安全可行的操作。本研究旨在探究诱导分娩对足月母马交感-迷走神经平衡的影响。本研究共纳入14匹母马，分为两组：一组接受自然分娩（spontaneous delivery, SD），另一组接受诱导分娩（induced delivery, ID）。两组均采用集成智能纺织电极的弹性腰带记录心电图（Electrocardiogram, ECG）。记录始于分娩前（Basal），持续至分娩临近阶段（Pre-delivery）、分娩过程中（Delivery），直至产后胎盘排出期（Placental expulsion）。从采集的心电图数据中，提取得到与时域、频域及非线性分析相关的心率变异性（Heart Rate Variability, HRV）参数。心率变异性分析分别在组内（IntraGA）与组间（InterGA）开展。本研究结果显示，自然分娩与诱导分娩的自主神经系统功能未见显著差异。组内分析表明，无论是自然分娩组还是诱导分娩组母马，分娩及胎盘排出阶段均以副交感神经占主导，这与迷走神经相关HRV参数的升高趋势相符。此外，组间对比未发现自然分娩组与诱导分娩组母马存在其他显著差异，仅诱导分娩组的临产期例外——该时段内自主神经系统的两个分支均被激活。上述结果与现有文献中关于分娩过程副交感神经占优、以及分娩母马经外源性催产素给药后心率变异性无显著变化的结论一致。