Andres R L, Saade G, Gilstrap L C, Wilkins I, Witlin A, Zlatnik F, Hankins G V
Department of Obstetrics, The University of Texas-Houston Medical School, Houston, USA.
Am J Obstet Gynecol. 1999 Oct;181(4):867-71. doi: 10.1016/s0002-9378(99)70316-9.
Our purpose was to correlate umbilical artery blood gas parameters with neonatal death and indicators of morbidity in neonates with pathologic fetal acidemia (pH <7.0).
We reviewed maternal and neonatal charts of 93 neonates with an umbilical artery pH <7.0 who were delivered at 2 university-based centers. The relationships between umbilical artery pH, PO (2), PCO (2), bicarbonate, base deficit, and neonatal variables-death, need for intubation, cardiopulmonary resuscitation, seizures, hypoxic-ischemic encephalopathy, respiratory distress syndrome, intraventricular hemorrhage, meconium, sepsis, and intrauterine growth restriction-were determined with the Student t test, Mann-Whitney U test, and multiple logistic regression analysis. Data are presented as either median with 25th-75th percentiles or mean +/- SD.
The mean gestational age at delivery was 37.9 +/- 3. 6 weeks, and the mean birth weight was 3003 +/- 866 g. There was no relationship between neonatal death, respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, patent ductus arteriosus, meconium, sepsis, and any umbilical artery blood gas parameter. The PO (2) was not related to any of the variables studied. A lower umbilical artery pH was associated with hypoxic-ischemic encephalopathy (6.69 vs 6.93, P =.03), cardiopulmonary resuscitation (6.83 vs 6.93, P =.03), seizure (6.75 vs 6.93, P =.02), intubation (6.83 vs 6.94, P <.001), and intrauterine growth restriction (6.72 vs 6.93, P =.01). Greater mean base deficit was associated with seizure (20.6 vs 15, P =.01), intubation (18.0 vs 13.7, P <.001), cardiopulmonary resuscitation (18.5 vs 15.0, P =.03), intrauterine growth restriction (22.0 vs 14. 0, P =.02), and hypoxic-ischemic encephalopathy (24.0 vs 14.5, P =. 03). Arterial PCO (2) was higher only in infants with hypoxic-ischemic encephalopathy (138 vs 95.5, P =.048), intubation (106.0 vs 90.5, P =.003), and cardiopulmonary resuscitation (106.5 vs 93.0, P =.04). After control for birth weight and gestational age in the multivariate analysis, base deficit and bicarbonate were independently related to death or morbidity.
Our data suggest that "pathologic" fetal acidemia is indicated by an umbilical artery pH <7.00 with a metabolic component. The metabolic component of fetal acidemia (ie, base deficit and bicarbonate) is the most important variable in subsequent neonatal morbidity. As expected, the umbilical artery PO (2) has no apparent clinical utility. The ability to predict more accurately which newborn infants with fetal acidemia are at risk of having complications may lead to a more efficient implementation of preventive measures.
我们的目的是将脐动脉血气参数与患有病理性胎儿酸血症（pH <7.0）的新生儿的死亡及发病指标相关联。
我们回顾了在2个大学附属医院中心分娩的93例脐动脉pH <7.0的新生儿的母婴病历。采用Student t检验、Mann-Whitney U检验和多因素逻辑回归分析确定脐动脉pH、PO₂、PCO₂、碳酸氢盐、碱缺失与新生儿变量（死亡、插管需求、心肺复苏、惊厥、缺氧缺血性脑病、呼吸窘迫综合征、脑室内出血、胎粪吸入、败血症和宫内生长受限）之间的关系。数据以第25至第75百分位数的中位数或均值±标准差表示。
分娩时的平均胎龄为37.9±3.6周，平均出生体重为3003±866 g。新生儿死亡、呼吸窘迫综合征、脑室内出血、坏死性小肠结肠炎、动脉导管未闭、胎粪吸入、败血症与任何脐动脉血气参数之间均无关联。PO₂与所研究的任何变量均无关。较低的脐动脉pH与缺氧缺血性脑病（6.69对6.93，P = 0.03）、心肺复苏（6.83对6.93，P = 0.03）、惊厥（6.75对6.93，P = 0.02）、插管（6.83对6.94，P <0.001）和宫内生长受限（6.72对6.93，P = 0.01）相关。较高的平均碱缺失与惊厥（20.6对15，P = 0.01）、插管（18.0对13.7，P <0.001）、心肺复苏（18.5对15.0，P = 0.03）、宫内生长受限（22.0对14.0，P = 0.02）和缺氧缺血性脑病（24.0对14.5，P = 0.03）相关。动脉PCO₂仅在患有缺氧缺血性脑病（138对95.5，P = 0.048）、插管（106.0对90.5，P = 0.003）和心肺复苏（106.5对93.0，P = 0.04）的婴儿中较高。在多因素分析中校正出生体重和胎龄后，碱缺失和碳酸氢盐与死亡或发病独立相关。
我们的数据表明，“病理性”胎儿酸血症表现为脐动脉pH <7.00且伴有代谢成分。胎儿酸血症的代谢成分（即碱缺失和碳酸氢盐）是随后新生儿发病的最重要变量。正如预期的那样，脐动脉PO₂没有明显的临床用途。更准确地预测哪些患有胎儿酸血症的新生儿有发生并发症风险的能力可能会导致更有效地实施预防措施。
