Ontogenetic development of neural control of the heart rate in the human fetus quantitatively assessed using a probability matrix.

在过去的3年中，我们使用概率矩阵，定量地分析了脑积水、无脑儿和正常胎儿的胎心率随年龄的变化。分析了20~41周正常胎儿胎心率随年龄变化的特征，以每2个连续胎龄的原始完整数据构建的标准矩阵与从原始数据集中随机抽取的小样本FIIR数据生成的矩阵之间的“符合率”为参数。对于标准概率矩阵，获得90%的“符合率”所需的FHR节拍的最小数量是27-28周的2700次，逐渐增加到34-35周的约6000次。两个有统计学意义的临界点分别出现在孕28~29周和孕34~35周。这些发现表明…的胎心率变异有3个不同的特征更多的是关于机制的。受试者在整个妊娠期的控制力。参照相应孕周的标准概率矩阵，以代表标准矩阵与受试者矩阵之差的“不符合率”为参数，评价无脑或脑积水胎儿心率变化随年龄的差异。在脑积水的胎儿中，不符合率在妊娠31-39周时保持在正常范围内，在11.8%到30.6%之间。相反，在无脑儿中，“不符合率”随着妊娠的推进而增加，从孕24周的15.9-40.6%增加到孕34周的36.5-45.3%。从妊娠31周开始，这些值都超出了正常范围。结合这些结果和尸检结果，这些结果表明，中枢神经系统，从头部到延髓，至少从怀孕31周起，开始在控制胎儿心率变化方面发挥重要作用。较少

For the past 3 years, we quantitatively analyzed, using a probability matrix, the age-related fetal heart rate changes in the fetuses with hydrocephalus and anencephalous as well as the normal fetuses.1. Analyzed was the age-related characteristics of FHR variation in normal fetuses from 20 to 41 weeks' gestation, using the "congruence rate" between the standard matrix constructed from the original whole data in each 2 consecutive gestational age and the matrix produced from a small sample of FIIR data randomly selected from the original data set, as a parameter. The minimum number of FHR beats necessary to get a "congruence rate" of 90% for the standard probability matrix was 2700 beats at 27-28 weeks' gestation, gradually increasing up to about 6000 beats at 34-35 weeks' gestation. Two statistically significant critical points were found to be at 28-29 weeks' and at 34-35 weeks' gestation. These findings indicate that there were 3 different characteristics of FHR variation pertaining … More to the mechanism. of PIIR control throughout the gestational periods studied.2. Refering to the standard probability matrix for the corresponding gestational week, the age-related differences in fetal heart rate change in anencephalic or hydrocephalic fetuses was evaluated, using the 'incongruence rate" as a parameter, representing the difference between the standard matrix and the subjected matrix. In hydrocephalic fetuses, the -incongruence rate- remained within the normal range, between 11.8 and 30.6% at 31-39 weeks' gestation. On the contrary, in anencephalic fetuses, the "incongruence rate" increased, with advance in gestation, from 15.9-40.6% at 24 weeks' gestation to 36.5-45.3% at 34 weeks' gestation. and the values were beyond the normal range from 31 weeks' gestation onwards. Combining these results with autopsy findings, these suggest that the central nervous system, cephalate to the medulla, begins to play a substantial role in the control of fetal heart rate changes, at least, from 31 weeks' gestation onwards. Less