van Vliet M A, Martin C B, Nijhuis J G, Prechtl H F
Am J Obstet Gynecol. 1985 Nov 1;153(5):582-8. doi: 10.1016/0002-9378(85)90483-1.
The incidence of fetal breathing was studied during the course of behavioral state observations on 28 low-risk fetuses between 32 and 40 weeks' gestational age and on 12 growth-retarded fetuses between 36 and 40 weeks. Real-time ultrasound scanners were used to detect fetal eye, body, and breathing movements, and the fetal heart rate was recorded continuously. The mean duration of the observation sessions was 110 minutes. The mean incidence of fetal breathing was greater during periods of fetal activity (body and eye movements present, greater heart rate variability) than during quiescence (body and eye movements absent, narrowed heart rate variability) at all gestational ages studied in both low-risk and growth-retarded fetuses. During periods when one of the state variables (body movements, eye movements, heart rate pattern) was in its active condition while the other two were quiet, or the reverse, the incidence of fetal breathing was intermediate between those found when all three state variables were in agreement. After behavioral states had developed, at 38 and 40 weeks, the mean incidence of fetal breathing in the low-risk fetuses was greater during active states than during the quiet state. There was no apparent increase in the degree of linkage between fetal breathing and other expressions of fetal activity after the emergence of behavioral states.
在对28例孕龄为32至40周的低风险胎儿以及12例孕龄为36至40周的生长受限胎儿进行行为状态观察的过程中，研究了胎儿呼吸的发生率。使用实时超声扫描仪检测胎儿的眼部、身体和呼吸运动，并持续记录胎儿心率。观察时段的平均时长为110分钟。在低风险胎儿和生长受限胎儿的所有研究孕龄中，胎儿活动期（存在身体和眼部运动，心率变异性更大）的胎儿呼吸平均发生率高于静止期（不存在身体和眼部运动，心率变异性变窄）。在其中一个状态变量（身体运动、眼部运动、心率模式）处于活跃状态而其他两个处于安静状态，或者相反的时段，胎儿呼吸的发生率介于三个状态变量一致时的发生率之间。在行为状态形成后，即孕38周和40周时，低风险胎儿在活跃状态下的胎儿呼吸平均发生率高于安静状态。行为状态出现后，胎儿呼吸与胎儿活动的其他表现之间的关联程度没有明显增加。
