분만중 태아심전수도 및 pH와 자궁수축곡선과의 상호관계에 관한 연구

Abstract

Accurate assessment of fetal condition during labor constitutes one of the major problems of modern obstetrics. For practical purposes, two methods are offered as promising approaches to this problem. viz .• continuous monitoring of the fetal heart rate and microblood sampling from the fetal scalp. This study was performed in an attempt to evaluate the correlation between fetal heart rate-uterine contraction (FHR-UC) patterns and fetal scalp blood pH (FSB-pH) in the terminal part of labor with neonatal outcome among 15 cases of normal term and 24 cases of high risk pregnancy admitted to Seoul National University Hospital from June 1 to December 31, 1976. The FHR was monitored with external cardiotocography and the FHR-UC record was analyzed for baseline FHR and periodic changes that were classified qualitatively according to Hon. Fetal scalp blood sampling was performed by the technique of Saling and the acid-base determinations were carried out on an IL-113 pH-blood gas system. The significance of FHR-UC monitoring as a means of predicting the condition of the fetus during labor was studied by correlating FSB-pH determinations with the analysis of the 20minute FHR-UC record preceding the fetal scalp blood sample. The obtained results are as follow: 1. There were 14 instances in the absence of any periodic change. The mean pH of this group was 7.318. Of the pH deteriminations, 12 (85.7%) were greater than 7.250 and only two values was s7.250 2. The mean pH of 6 determinations associated with periodic accelerations was 7.325 with all(100%) >7.250. The mean pH of 10 determinations associated with early decelerations was 7. 312 with 9 (90%) >7.250 3. The mean pH of the group of 5 variable decelerations was 7. 289, which was much Icwer than the group without periodic changes. Of the 5, 3 (60%) were associated with a pH >7.250, and 2 (40%) with a pH ~7. 250. 4. The mean pH of the group of 4 late decelerations was 7.254, which was significantly lower than the group without periodic change. Only one (25%) of the pH values was >7.250, and three (75%) s7.250 5. There is a less than 15% chance of fetal pH ~7. 250 with a normal baseline FHR and no periodic changes or with the so-called "innocuous" changes of periodic accelerations, early decelerations, and uncomplicated baseline bradycardia or tachycardia. 6. The analysis of the so-called "ominous" patterns indicated that 40% of all variable decelerations and 75% of all late deceleration patterns were associated with a pH ~7. 250. 7. In correlating FHR-UC patterns with Apgar scores at 1 minute, it was found that the mean Apgar score, associated with ominous patterns, was much lower than that seen with no significant FHR-UC changes. However, in the presence of late decelerations 50% of neonates had an Apgar score of greater than 6 at 1 minnte, and with variable decelerations, 60% of neonates had an Apgar score at one minute of more than 6. 8. However, where the FSB-pH was ~7. 2, neonatal depression (Apgar score ~6) occurred in all (100%) of two cases. FSB-PH, therefore, provided a more reliable means of diagnosing fetal distress.