Izumi A, Minakami H, Sato I
Department of Obstetrics and Gynecology, Jichi Medical School, Minamikawachi-machi, Tochigi, Japan.
Gynecol Obstet Invest. 1997;44(1):26-31. doi: 10.1159/000291404.
To determine the relationship between abnormal fetal heart rate (FHR) patterns, fetal oxygen content by reflectance pulse oximetry, and the effects of maternal oxygen administration, 158 intrapartum women consisting of 120 women with normal FHR patterns, and 38 women with varying degrees of variable FHR decelerations were examined. A new reflectance pulse oximetry probe was attached to the fetal forehead to continuously monitor fetal oxygen saturation (SpO2) during labor. Oxygen was administered for 30 min at 5 liters/min by nasal canula in 32 women. No significant change in fetal SpO2 was seen in women with normal FHR patterns, but a significant decline in SpO2 was observed shortly before births. FHR decelerations less than 90 bpm occurred prior to the decline in fetal SpO2. Maternal oxygen administration was effective in increasing fetal SpO2 in fetuses with decreased SpO2 (SpO2 < 50%), but not in fetuses with high SpO2 (SpO2 > 60%). It is concluded that fetal SpO2 exhibits no change during normal labor but significantly declines shortly before birth, that relatively severe variable decelerations (<90 bpm) can decrease fetal SpO2, and that maternal oxygen treatment at 5 liters/min is effective in augmenting fetal oxygen tension in fetuses with decreased oxygen tension.
为了确定异常胎儿心率（FHR）模式、通过反射式脉搏血氧饱和度测定法测得的胎儿氧含量以及母体吸氧的效果之间的关系，对158名分娩期妇女进行了检查，其中包括120名FHR模式正常的妇女和38名有不同程度变异FHR减速的妇女。在分娩期间，将一种新型反射式脉搏血氧饱和度测定探头附着在胎儿前额，以持续监测胎儿血氧饱和度（SpO2）。32名妇女通过鼻导管以5升/分钟的流量吸氧30分钟。FHR模式正常的妇女胎儿SpO2未见明显变化，但在出生前不久观察到SpO2显著下降。胎儿SpO2下降之前出现了低于90次/分钟的FHR减速。母体吸氧对SpO2降低（SpO2 < 50%）的胎儿提高SpO2有效，但对SpO2高（SpO2 > 60%）的胎儿无效。结论是，胎儿SpO2在正常分娩期间无变化，但在出生前不久显著下降，相对严重的变异减速（<90次/分钟）可降低胎儿SpO2，并且以5升/分钟的流量进行母体吸氧对氧分压降低的胎儿提高胎儿氧分压有效。
