胎児の病態生理学的変化に基づく分娩時心拍数モニタリングの再評価(2 wellbeingの臨床的評価法 : その精度と限界)

概要

論文の詳細を見る
Objectives : Intrapartum fetal heart rate (FHR) monitoring is under reevaluation of its clinical importance. We thus performed a clinical study in which we used the HICHD guideline for FHR interpretation and applied our standarad management protocols for obstetric and neonatal cares including NICU. We also investigated a new technology to estimate fetal blood pressure in labor in acute animal models to search for a supplementary method for FHR monitoring to compensate for its limitation. Methods: A retrospective study was performed in low risk pregnancies, and high risk pregnancies such as IUGR (intrauterine growth restriction) and JUl (intrauterine infection). 10,030 deliveries between 1995 and 2001 were enrolled. 5,522 were deemed as low risk pregnancies and delivered singleton at ≥32 weeks gestation, 433 were IUGR, and 145 were JUl. Animal studies were also performed in 7-day-old newborn rats to see the effect of intrauterine infection on hypoxic-ischemic brain damage, and goat fetuses at at〜0.85 gestation (term = 147 days) to correlate intraarterial blood pressure and their estimates derived from the pulse wave velocity. Unpaired t test, chi-square test, one-way ANOVA, Pearson correration test were used. Results: Intrapartum FHR monitoring resulted in no change in 52%, mild variable deceleration (VD) in 29 %, moderate VD in 5%, severe VD in 2%, prolonged D in 5%, occasional late deceleration (LD) in 5%, and recurrent LD in 2%. Umbilical blood gas analysis revealed 1) more severe the VD developed resulted in more hypoxemic and acidemic, 2) occasional LD was hypoxemia alone, and 3) recurrent LD was hypoxemia with acidemia. Positive predictive value for low pH (<7.1) was at most 10% in recurrent LD and prolonged D, but negative predictive value was high (>99%). There was one cerebral palsy (CP) resulting from prolonged D whose mother sufferd from amniotic fluid embolism. In IUGR, umbilical blood gas analyses showed simliar patterns as low risk pregnancies, except that recurrent LD and prolonged D were mani-fested when PO_2 was decreased to a lesser extent. Incidence of CP in IUGR was high with recurrent LD or prolonged D compared to those with no change. Multiple logistic regression analysis revealed that no significant factors of FHR monitoring was related to CP. In IUI, blood gas analyses showed similar patterns as low risk pregnancies, except that fetal PO_2 levels were elevated by 5mmHg and that PCO2 levels were decreased. Multivaritate analyses revealed that fetal tachycardia (OR = 11) and moderate〜severe VD (OR = 5) were significantly related to CP. Animal experiments also showed an additive effect between hypoxia-ischemia and infection (lipopolysaccharide)to cause brain damage. The pulse wave velocity was determined in each cardiac cycle by the time difference from R-wave on electrocardiogram to maximum upstroke of fetal oximetry waveform placed on the tongue. Blood pressure was decreased by 10% by hydralazine or blood withdrawal, resulting in a significant correlation between the intra-arterial blood pressures and the estimates. Correlation coefficients were high (average r2 >0.8) and reproducible in hydralazine and blood withdrawal experimets. Conclusions: We speculated that the threshold to cause non-reassuring FHR patterns was changed according to the fetal pathophysiologic conditions and that the threshold for CP was also set at a higher level such that a mild decrease in fetal oxygenation results in CP in IUGR and IUI. Estimates of blood pressure correlated well with arterial blood pressue, which has a clinical relevance because once the uterine cervix is dilated and membranes are ruptured, fetal electrocardiogram and fetal oximetry are easily obtained. This technology may open a new basic and clinical research.
社団法人日本産科婦人科学会の論文
2002-08-01

胎児の病態生理学的変化に基づく分娩時心拍数モニタリングの再評価(2 wellbeingの臨床的評価法 : その精度と限界)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク