Comparison of epidural and general anaesthesia for elective caesarean delivery according to the effects of apgar scores and acid-base status

The objective of this study was to determine the effects of lumbar epidural anaesthesia on the Apgar score and acid-base status of the newborn. Umbilical artery blood gases were obtained in 85 singleton, term, uncomplicated pregnancies delivered by elective Caesarean section. The umbilical artery blood pH, PaCO2, PaO2 and HCO3 values and Apgar scores (1 and 5 minutes) were compared between lumbar epidural and general anaesthesia groups. General anaesthesia was used in 45 (52.9%) women and lumbar epidural anaesthesia in 40 (47.1%). Only 2 of the newborns exposed to epidural anaesthesia had umbilical artery blood pH values 7.19 or less. The mean umbilical artery blood pH was found to be significantly lower in the newborns exposed to lumbar epidural anaesthesia (p = 0.011). None of the newborns in the 2 groups were severely depressed (Apgar scores less than 4). The mean umbilical artery blood PaCO2, PaO2 and HCO3 values did not show any significant difference between the groups. In conclusion, lumbar epidural anaesthesia is associated with lower umbilical artery blood pH values, occasionally with severe fetal acidaemia.     

Comparison of umbilical artery pH and 5-minute Apgar score in the low-birth-weight and very-low-birth-weight infant

The division between "normal" and low Apgar scores is based largely on data obtained from term newborns and may not apply to the premature infant. Umbilical artery pH has been suggested as a better indicator of intrapartum asphyxia. We examined the charts of 558 infants with birth weights less than or equal to 2500 gm with respect to umbilical artery pH, 5-minute Apgar scores, and birth weight percentiles. A positive correlation between birth weight and 5-minute Apgar score was noted. No such relationship existed between birth weight and umbilical artery pH. Within birth weight groups, small-for-gestational-age infants have higher Apgar scores and lower umbilical artery pH values than their appropriate-for-gestational age counterparts.     

Apgar scores and umbilical arterial pH in preterm newborn infants

One- and five-minute Apgar scores and umbilical cord arterial pH values were compared in preterm newborn infants of various gestational ages. The more premature the infant, the more likely the Apgar score was low in the presence of a pH greater than or equal to 7.25. Conversely, the closer to term, the more frequently an infant with a pH of less than 7.25 had an Apgar score of greater than or equal to 7. Therefore, in preterm infants, there is little congruity between the Apgar score and umbilical cord pH. Based on these findings, it is not appropriate to label preterm newborn infants as asphyxiated based on a low Apgar score.     

The effect of preterm birth on umbilical cord blood gases.

Apgar scores are used routinely to assess early neonatal status, but are less accurate in the preterm neonate because of developmental immaturity. Attention has been directed to umbilical cord gases as a method of neonatal evaluation. Using a retrospective chart review of all viable preterm births (24-36 weeks' gestation) between January 1986 and December 1989, we tabulated the umbilical cord gas indices of these infants. Fetuses with lethal congenital anomalies and those with abnormal heart rate tracings on admission were excluded from the data base, leaving 1872 infants. Cord arterial blood gas values were available for analysis in 74.4% of cases and cord venous gas values in 81.8%. The mean (+/- standard deviation [SD]) arterial and venous umbilical cord blood gas values for the preterm infants, were, respectively: pH, 7.26 +/- 0.08 and 7.33 +/- 0.07; oxygen pressure, 19.0 +/- 7.9 and 29.2 +/- 9.7 mmHg; carbon dioxide pressure, 53.0 +/- 10.0 and 43.4 +/- 8.3 mmHg; bicarbonate, 24.0 +/- 2.3 and 22.8 +/- 2.1 mEq/L; and base excess, -3.2 +/- 2.9 and -2.6 +/- 2.5 mEq/L. Acidemia was defined statistically as 2 SDs or more below the population mean. The incidence of 5-minute Apgar scores below 7 in the preterm infants was 8.5% and within this group, 17.8% were acidemic (arterial pH 7.10 or lower). More than 82% of neonates with 5-minute Apgar scores less than 7 had normal umbilical cord blood gases. There was no significant difference in umbilical arterial blood gas values between preterm infants and 1924 term deliveries at our institution between 1986-1988.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnosis of birth asphyxia on the basis of fetal pH, Apgar score, and newborn cerebral dysfunction

Imprecise diagnosis of birth asphyxia coupled with uncertainties about causal factors for neurologic abnormalities in the newborn have greatly fueled the current litigation crisis in obstetrics. Our goal was to more precisely define birth asphyxia based on fetal condition as measured by umbilical artery blood pH, Apgar scores, and neurologic condition of newborns. We selected for study 2738 patients with singleton pregnancies with cephalic presentations who were delivered of infants at term to avoid complications such as prematurity, which may affect infant outcome independent of birth condition. The basis for study of these particular patients were defined criteria for high risk and an indicated arterial cord pH value. A total of five infants demonstrated cerebral dysfunction as evidenced by seizures during the neonatal period. Infection was linked to seizures in three of these infants; one infant had neonatal asphyxia and only one infant's clinical course could be attributed solely to birth events (uterine rupture). Stratification of umbilical artery blood pH values, Apgar scores, and combinations of these dependent variables in relation to newborn clinical outcomes revealed that infants must be severely depressed at delivery before birth asphyxia can be reliably diagnosed. Such depression includes Apgar scores less than or equal to 3 at 1 and 5 minutes plus umbilical artery pH values less than 7.00.     

Routine umbilical cord blood gas determinations?

Between 1986 and 1988, 1924 term nulliparous patients with spontaneous onset of labor were studied to assess the importance of obtaining umbilical cord blood gas levels on all deliveries. The umbilical cord arterial and venous pH values (expressed as mean +/- 2 SD) were 7.24 +/- 0.14 (n = 1694) and 7.32 +/- 0.12 (n = 1820), respectively. The incidence of newborn depression (1- or 5-minute Apgar score less than 7) was 14.1%; of these depressed newborns, the incidence of normal umbilical cord arterial pH values (greater than or equal to -2 SD) was 77.8%. Of the vigorous newborns, there was a 2.1% incidence of umbilical cord arterial blood acidemia. Umbilical cord arterial blood acidemia in vigorous newborns was not highly predictive of specific morbidity in the immediate newborn period. Regression analysis demonstrated the umbilical cord arterial pH to correlate best with the Apgar scores when compared with all other arterial or venous blood gas measurements. We reached the following conclusions: (1) that obtaining cord arterial pH values in vigorous newborns should be considered since the values will provide objective documentation or normal fetal acid base balance in 98% of infants. (2) Only a cord arterial pH determination is recommended since it reflects fetal or newborn status more accurately than all other measurements. Additional measurements increase the likelihood of abnormal results and do not contribute to neonatal management. (3) An umbilical cord blood pH value is extremely useful in ruling out the diagnosis of birth asphyxia in the depressed newborn.     

An assessment of the use of meconium alone as an indication for fetal blood sampling.

OBJECTIVE: To assess the validity of meconium as an indication for fetal blood sampling. METHODS: The study design was a prospective observational study in a teaching hospital. Fetal blood samples were taken from 401 women. One hundred sixty-five patients had meconium-stained amniotic fluid (77 of whom had no cardiotocographic abnormalities). In the remaining 236 patients, the indication for fetal blood sampling was cardiotocographic abnormalities without meconium. The main outcome measures were the values of pH and base excess obtained at fetal blood sampling, 1-minute Apgar scores, and umbilical artery pH values. RESULTS: Patients with meconium alone as an indication for fetal blood sampling had higher scalp sample pH values (P < .001) and 1-minute Apgar scores (P < .01) than laboring patients with both meconium and cardiotocographic abnormalities. The patients with meconium alone had higher scalp pH values than patients with cardiotocographic abnormalities but no meconium (P < .001). In only two patients with meconium alone was a fetal scalp pH less than 7.20 (both infants had good Apgar scores at delivery). However, when cardiotocographic abnormalities were present, the finding of meconium was significant, resulting in lower 1-minute Apgar scores (P < .01) despite a lack of difference in fetal blood sample pH values. CONCLUSION: In the absence of cardiotocographic abnormalities, meconium is not an indication for fetal blood sampling.     

Neonatal complications at term as related to the degree of umbilical artery acidemia

The degree of umbilical arterial acidemia associated with immediate newborn morbidity has not been determined. Therefore we compared 358 term infants with umbilical artery acidemia (pH less than 7.20) with 358 term, nonacidotic matched control infants, to evaluate immediate neonatal complications in both groups. Nonacidotic was defined as an umbilical artery pH greater than or equal to 7.20. Complications included seizures, persistent hypotonia, and/or signs of end-organ damage such as renal or cardiac dysfunction. None of the 693 newborns with an umbilical artery pH greater than or equal to 7.00 had such complications. Two of 23 infants with an umbilical artery pH less than 7.00 had sequelae related to intrapartum asphyxia. In these two infants the umbilical artery pH was less than 7.00, the 1-minute and 5-minute Apgar scores were less than or equal to 3 and the acidemia was metabolic in nature.     

Umbilical cord blood gases for term healthy newborns

Examination of paired umbilical arterial and umbilical venous blood gases for 147 term, healthy newborns revealed a strong correlation of pH, bicarbonate, and base excess with the 1-minute Apgar score. Although significantly different from each other, a strong correlation existed between the gas measurements of the two vessels. The lower limit of pH for the umbilical artery was 7.12 and for the vein, 7.25. The arterial-venous difference for bicarbonate but not pH, oxygen or carbon dioxide tension, or base excess was correlated with the 1-minute Apgar score.     

The Northwestern University triplet study. IV. Biochemical parameters

Umbilical arterial and venous blood gas indices of 11 triplet pregnancies were reviewed. Ten sets of triplets were delivered by cesarean section and one set was delivered vaginally. Mean 1-minute Apgar scores were significantly lower in the group of infants delivered third than in either of the other birth order groups. There were no statistically significant differences when the mean umbilical arterial or venous pH, PCO2, and base deficit were compared among any one triplet and the other two. Similarly, no significant differences were found when these parameters were compared by birth order in relation to mean 5-minute Apgar scores, mean birth weights, and mean gestational ages at delivery. Birth order did not appear to significantly influence acid-base status, although it may become significant with an increasing time in utero after delivery of the firstborn infant. Further study is necessary to investigate whether there is a critical interval of delivery whereby the infants remaining in utero become acidotic.     

Umbilical cord pH and base excess values in relation to neonatal morbidity for infants delivered preterm

OBJECTIVE: Our purpose was to determine the relationship/predictive value of umbilical cord pH and base excess (BE) values to adverse neonatal outcomes for preterm infants. STUDY DESIGN: A tertiary center perinatal/neonatal database was used to obtain umbilical cord pH and BE values, adverse neonatal outcomes, and patient demographics for preterm (PT, 32-36 weeks gestational age) and very preterm (VPT, 25-32 weeks gestational age) singleton live-born infants delivered between November 1995 and March 2002. RESULTS: PT (n=1807) and VPT (n=603) groups demonstrated a significant inverse curvilinear relationship of umbilical cord pH and BE values to Apgar score <7 at 5 minutes, respiratory distress syndrome, assisted ventilation, and intraventricular hemorrhage/periventricular leukomalacia. Receiver operating characteristic area under the curve values ranged from 0.69 to 0.86 (PT) and 0.70 to 0.87 (VPT). There was little difference between umbilical vein, umbilical artery, pH, or BE in predictive value. CONCLUSION: Umbilical cord pH and BE are related to subsequent adverse outcome events for infants delivered preterm. Worsening acidosis is associated with progressively greater increases in these outcomes with no discriminatory value within or between umbilical artery and umbilical vein pH and BE.     

Hypoglycemia in newborn of the diabetic mother in relation to some indicators of perinatal hypoxia

DESIGN: To examine whether perinatal hypoxia increases the risk of occurrence of hypoglycaemia--between first and second hour of life--in newborn of the diabetic mother. MATERIAL AND METHODS: The study material consisted of 151 newborns born to 58 pregestational and 93 gestational diabetes mothers. The occurrence of hypoglycaemia was examined in accordance with some perinatal hypoxia indicators such as: 1 and 5 minutes Apgar scores, umbilical arterial blood gas analysis and cord blood erythropoietin (EPO) level. RESULTS: Newborns of the diabetic mothers in whom hypoglycaemia was recognised had lower 1 minutes Apgar scores, lower pH values, higher pCO2 values and higher EPO levels than those, in whom normoglycaemia was recognised. CONCLUSIONS: Low 1 minutes Apgar scores and occurrence of even mild perinatal hypoxia are factors increasing the risk of hypoglycaemia in the group of newborns of the diabetic mothers in the time between first and second hour of life.     

A prospective study on buprenorphine use during pregnancy: effects on maternal and neonatal outcome

BACKGROUND: Exposure to illicit drugs in utero is associated with low birth weight and premature birth. Therefore, maintenance therapy for opioid dependence during pregnancy has been recommended to help withdrawal from street drugs, in order to improve maternal health and decrease risks to the fetus. METHODS: In 2002-2005, 67 pregnancies of 66 buprenorphine users were followed prospectively in an outpatient multidisciplinary antenatal setting by an obstetrician, a midwife, a psychiatric nurse and a social worker. Decreasing doses or even abstinence from buprenorphine was encouraged. Outcome measures were daily buprenorphine dose, fetal growth, gestational age at birth, mode of delivery, birth weight, Apgar scores, umbilical pH values, and occurrence of neonatal abstinence syndrome [NAS]. National statistics were used as reference values. RESULTS: The daily dose of buprenorphine decreased by 2.3 mg (median, range increase of 8 mg to decrease of 24 mg). There were no more incidences of premature birth, cesarean section, low Apgar scores (< or = 6) or umbilical artery pH <7.05 at birth than in the national register, despite the lower birth weight. A total of 91% of the infants needed treatment in a neonatal care unit, 76% had NAS, and 57% needed morphine replacement therapy. Seven infants were taken into care directly from the maternity hospital. Two sudden infant deaths occurred later. CONCLUSIONS: The pregnancies and deliveries of buprenorphine-using women were uneventful, but severe NAS and need for morphine replacement therapy was seen in 57% of the buprenorphine-exposed newborns. A high number of sudden infant deaths occurred.     

Acidosis in newborns with nuchal cords and normal Apgar scores.

OBJECTIVE: Apgar scores and cord blood gases (BG) and pH were compared between a group of babies with nuchal cords and a group without nuchal cords and uncomplicated deliveries. STUDY DESIGN: We collected umbilical arterial (UA) and umbilical venous (UV) blood samples from the placentas of term infants from both normal deliveries (NORM, n=29) and nuchal cords (NUCH, n=33). BG/pH and hematocrit were measured; base deficits and oxygen contents were calculated; and a member of the study assigned Apgar scores and demographic data were collected from the babies' charts. RESULTS: Median Apgar scores in the NUCH babies at 1 and 5 minutes were 9 and 9 respectively, which did not differ from the NORM infants. The pH, PCO(2), and oxygen content obtained from UV of the NUCH infants was not statistically different from the NORM. The pH and oxygen content of the NUCH UA was significantly lower than that of the NORM. The UA PCO(2) in the NUCH was greater than the NORM. Veno-arterial (VA) differences (Delta VA) in pH and PCO(2) of the NUCH infants were greater than that of the NORM. CONCLUSION: The Apgar score is not a sensitive indicator of acid-base changes in nuchal cord patients; UV samples alone may be misleading. UA must be sampled to detect the hypercapnia and diminished oxygen content that is a result of the nuchal cord.     

产时不同类型胎儿酸血症与胎心监护图形的关系

目的研究产时脐动脉血显示的不同类型酸血症与产时胎心监护图形变化的关系及产后４年随诊的结果。方法采用回顾性病例对照研究方法,选择对象为１９９１年单胎、足月分娩的２９８１例新生儿,产程中定时胎心监护,分娩时测定脐动脉血气。生后４年进行儿童随诊。结果纯代谢性酸血症４７例（代酸组）,混合性酸血症６７例（混酸组）,该两组在第一产程末,胎心率评分＜６和６～７分者发生率显著高于对照组。减速图形特点显示晚期减速与纯代谢性酸血症有关,而异常可变减速与混合性酸血症有关。两组产后１分钟Ａｐｇａｒ评分＜７分者也明显高于对照组。儿童４岁时随诊其发育、运动和语言能力显示：代酸组及混酸组和对照组比较差异无显著性,只在混酸组语言表达迟钝的例数略多。结论晚期减速可能是纯代谢性酸血症的一个表现,而异常可变减速可能是混合性酸血症的一个表现。两者均与１分钟Ａｐｇａｒ评分低分的发生有密切关系。产时酸血症和以后的语言发育缺陷间关系需进一步估价     

Building evidence for practice: a pilot study of newborn bulb suctioning at birth

The purpose of the study was to examine the effects of bulb suctioning on healthy, term newborns and the feasibility of conducting a large-scale study of this practice. In a randomized, controlled two-group design pilot study, 10 newborns received oronasopharyngeal bulb suctioning at birth and 10 did not. Differences in Apgar scores, heart rates, and oxygen saturation levels were determined. Infants were randomized to groups before delivery. The participants were 20 term, healthy newborns of uncomplicated pregnancies. Apgar scores, heart rates, and oxygen saturation levels in the first 20 minutes of life were the main outcome variables. There were no statistically significant differences in Apgar scores between groups. Apgar scores at 5 and 10 minutes were 9 or 10 for all newborns. Newborns receiving bulb suctioning showed a statistically significant, lower heart rate (P=.042) during the first 20 minutes and a significantly higher SpO2 level (P=.005) by 15 minutes of age. Although statistically significant, these findings were not considered clinically significant because values remained within normal parameters.     

Lack of correlation between umbilical artery pH, retinal hemorrhages and Apgar score in the newborn

Measurement of pH was carried out in blood from the umbilical artery in 100 uncomplicated deliveries immediately after birth. The data were correlated with the results of fundoscopic examination carried out on the same infants within the subsequent 24 h. No relationship could be demonstrated between the grade of retinal hemorrhages and the cord blood pH measurements. Similarly, none of the neonatal birth parameters, including Apgar scores, could be related to individual differences in umbilical blood pH or the incidence or grade of retinal bleedings. The duration of bearing down was significantly and positively correlated (p less than 0.001) to the degree of acidosis in the umbilical blood. It is concluded that the presence of retinal hemorrhages provides little or no information about neonatal wellbeing or the impact of spontaneous birth on the fetus.     

The relationship between Apgar score, umbilical artery pH and operative delivery for fetal distress in 2778 infants born at term

A total of 2778 infants born at term were studied to determine the relationship between Apgar scores after 1 min, umbilical artery pH values, mode of delivery, a diagnosis of fetal distress leading to operative delivery, and sex. Eighty-three percent of the population had normal Apgar scores (greater than or equal to 8) and normal pH values (greater than 7.15) in which 10% were operatively delivered for fetal distress (ODFD). Sixty-one percent of the children with low Apgar scores (less than or equal to 7) had normal pH values, and 74% of the infants with acidosis (pH less than or equal to 7.15) had normal Apgar score. Twenty-four percent of the infants with a low Apgar score and/or acidosis were ODFD (sensitivity). Ninety percent of the infants who had Apgar scores and pH values were not ODFD (specificity). The predictive value (a low Apgar score and/or acidosis) of ODFD was 33%, and the negative predictive value (normal Apgar score and a normal pH) of ODFD was 85%. A significantly higher incidence of ODFD and acidosis was found in boys.     

The relationship of Apgar scores, gestational age, and birthweight to survival of low-birthweight infants

While Apgar scores provide a valid prediction of mortality in term infants (primarily reflecting asphyxia), intervening variables in premature newborns complicate interpretation. Physiologic states normal to preterm infants (such as, decreased muscle tone) can depress scores but may not influence survival significantly. Therefore the relationship between Apgar scores and survival in term and preterm infants differs. Because of the paucity of studies on preterm infants, we tested Apgar scores, as well as birthweight and gestational age, as outcome predictors in 748 low-birthweight infants (500-1800 gm). Our purpose was to assess the relationship between 1- and 5-minute Apgar scores and survival, and to evaluate all combinations of the four variables as outcome predictors. Univariate analysis showed a significant relationship between each of the four variables and survival; however, no single variable accounted for more than 32% of the variance in outcome, thus no single factor could be invoked as the major determinant of survival. Logistic regression analyses demonstrated the interrelationships of the four variables to survival. While both Apgar scores were related to survival, independent of the effects of birthweight and gestational age, they were slightly less predictive than either of these variables alone. However, when 1- and 5-minute Apgar scores were combined with gestational age, the predictive value was slightly better than any of the four variables alone or in other possible combinations.     

Acid-base evaluation of umbilical cord blood: relation to delivery mode and Apgar scores

Acid-base status of umbilical artery and vein blood was measured immediately after delivery in 300 cases. A slight acidosis of mixed respiratory/metabolic type was found in newborns delivered following a second stage of 10-30 min duration. After a second stage of more than 30 min the metabolic contribution to the acidosis was predominating. With Apgar scores lower than 10 the pH was found to decrease and carbon dioxide tension to increase. Induction or augmentation of labor by oxytocin did not influence the acid-base status of umbilical cord blood. Delivery by vacuum extraction or low forceps resulted in lower pH and higher carbon dioxide tension in umbilical cord blood, but the changes were associated with the indication for instrumental delivery and not with mode of delivery. A large arterio-venous difference between the acid-base parameters was usually connected to vigorous newborns and a small difference to depressed infants. The carbon dioxide tension was usually increased in newborns with decreased pH, and a close correlation between these parameter was found. No case of acidosis (pH below 7.15) was found in this population at carbon dioxide tensions below 7.2 kPa; at higher Pco2 values only 25% of the newborns were acidotic. A Pco2 level of 7.7 kPa might be used at transcutaneous carbon dioxide monitoring during labor, although the sensitivity and specificity of this parameter will have to be decided in a prospective study.