Mean Umbilical Artery pH Research Articles

Amnioinfusion in term labor with low amniotic fluid due to rupture of membranes: a new indication

Objective: The null hypothesis was that the use of intrapartum amnioinfusion to induce term labor because of premature rupture of membranes when labor was complicated by low amniotic fluid volume due to vaginal loss would not improve fetal heart rate patterns, decrease the incidence of operative delivery, or improve neonatal acid–base status. Study design: 200 term pregnancies with low amniotic fluid due to vaginal loss were randomly chosen to receive intrapartum amnioinfusion or standard obstetric care without amnioinfusion. Fetal heart rate pattern, method of delivery and neonatal acid–base status were compared with Student's t test, chi-squared analysis, Mann–Whitney U- or Fisher's exact test. Results: When amnioinfusion was used, the fetuses had lower rates of variable (74 vs 91%, P<0.01) or late (26 vs 58%, P<0.001) decelerations. Spontaneous deliveries were more frequent (77 vs 59%, P<0.01) and cesarean sections less frequent (3 vs 10%, P<0.05). Mean umbilical arterial (7.24±0.07 vs 7.21±0.08, P<0.01) and venous (7.31±0.06 vs 7.28±0.08, P<0.01) pH were significantly higher in newborns with amnioinfusion, and babies in this group had lower rates of neonatal acidemia of arterial (22 vs 36%, P<0.005) or venous (13 vs 26%, P<0.005) origin. Conclusions: Amnioinfusion improved fetal heart rate pattern, lowered the incidence of operative delivery, and improved neonatal acid–base status in term labor complicated by low amniotic fluid due to vaginal loss.

Umbilical cord blood pH after prior cesarean delivery

Objective: To determine the mean umbilical arterial (UA) pH and incidence of UA pH less than 7.10 in infants born to women with histories of prior cesareans. Methods: Three groups were studied retrospectively. Elective repeat cesarean ( n = 113), cesarean after labor ( n = 58), and successful vaginal birth after cesarean (VBAC) ( n = 135). Comparisons were made across all groups and between elective cesarean and patients who labored. Results: The mean UA pH values were 7.22 for elective cesarean, 7.20 for cesarean after labor, and 7.24 for VBAC ( P = .04). Among the patients who had elective cesareans, 11 (10%) of 110 had a UA pH of less than 7.10, compared with 11 (6%) of 185 among patients who labored, P = .25, odds ratio 0.6, 95% confidence interval 0.22, 1.47. Conclusion: Comparing neonates who underwent trials of labor with those delivered by cesarean, there was no significant difference in the percentage with UA pH values less than 7.10, suggesting vaginal delivery after previous cesarean does not have a deleterious effect on umbilical cord gases. However, our sample size precluded us from examining lower cut points for UA pH, which are of greater clinical significance. Therefore, these results should be interpreted cautiously until confirmed by other studies.

Amnioinfusion in labor induction of term pregnancies with premature rupture of the membranes and low amniotic fluid

Objective: To analyze the utility of prophylactic amnioinfusion in term pregnancies with PROM and a low amniotic fluid index during labor induction. Method: Forty-two women with amnioinfusion and 42 in a control group with amniotic fluid index (AFI) below 10 cm when admitted to labor induction were studied. All patients had electronic fetal heart rate and intrauterine pressure continuous monitoring. Amnioinfusion of normal saline (37°C) was realized in the study group, using a continuous perfusion pump at 600 ml/h for 1 h, after which the AFI was again recorded; if this was<15, the perfusion was continued at 180 ml/h until full cervical dilatation was achieved or until uterine baseline activity reached 20 mm Hg. The control group received identical obstetric care except in respect of amnioinfusion. Result: Both groups were similar in age, primiparity, gestational age, initial AFI, interval from rupture of membranes until delivery and length of labor. The amnioinfusion of 600 ml in 1 h significantly increased the AFI (an increase of 7.2±3.9 vs. a decrease of 1.1±1.6, P<0.01). In the amnioinfusion group, there was a significantly lower rate of cesarean deliveries (0 vs. 6, P<0.05) and a better mean umbilical arterial pH at delivery (7.24±0.07 vs. 7.21±0.08, P<0.05). No differences were observed in maternal or neonatal hospitalization days or infectious morbidity. Conclusion: It is concluded that prophylactic amnioinfusion improves neonatal metabolic state when used in labor induction of term pregnancies with PROM and a low amniotic fluid index.

Prospective validation of a scoring system for predicting neonatal morbidity after acute perinatal asphyxia

Objective: To prospectively validate a previously reported scoring system for identifying the near-term infant at risk for the multiple organ system sequelae of acute perinatal asphyxia. Study design: Prospective observational study. Setting: Three Denver teaching hospitals, each providing comprehensive obstetric care. Subjects: Newborn infants of 36 weeks or more gestation. Intervention: None. Statistical analysis: Chi-squared analysis with Fisher's exact test. Outcome: Scores consisting of graded abnormalities in fetal heart rate monitoring, umbilical arterial base deficit, and 5-minute Apgar score were calculated by the research nurse after admission of the infant to the nursery (range of possible scores, 0 to 9). A second nurse, blinded to these data, prospectively followed the newborn's hospital course for multiple organ system morbidity. Results: Three thousand two hundred thirty-eight newborns were studied; 366 required neonatal intensive care unit admission. Eleven newborns had a score ≥ 6 (mean umbilical artery pH = 6.98, base deficit = 17.1 mEq/L). Morbidities in these 11 newborns included seizures (2), hypoxic-ischemic encephalopathy (5), respiratory distress (9), hypotension (7), renal dysfunction (9), hypoglycemia/hypocalcemia (4), and thrombocytopenia or disseminated intravascular coagulopathy (3). The odds ratio (OR) and 95% confidence interval (CI) for newborns admitted to the neonatal intensive care unit with a score ≥ 6 for having multiple organ system morbidity, defined as three or more affected organ systems, was 38.5 (95% CI, 9.2 to 127.8). The scoring system showed a stronger relationship with multiple organ system morbidity than did isolated individual indicators commonly used to identify asphyxia calculated on the same subjects: for those with pH < 7.00, OR 24 (95% CI, 6.4 to 94.1); base deficit ≥ 10 mEq/L, OR 4.5 (95% CI, 1.9 to 10.3), and 5-minute Apgar score ≤ 3, OR 7.4 (95% CI, 1.3 to 38.1). Conclusion: This scoring system, encompassing both immediate intrapartum and postpartum measures and acid-base status proximate to the time of delivery, is useful for rapidly identifying the term and near-term newborn at risk for multiple organ system morbidity after acute perinatal asphyxia. (J Pediatr 1998;132:619-23)

Randomized trial of bolus phenylephrine or ephedrine for maintenance of arterial pressure during spinal anaesthesia for Caesarean section

Thirty-eight healthy women undergoing elective Caesarean section under spinal anaesthesia at term were allocated randomly to receive boluses of either phenylephrine 100 micrograms or ephedrine 5 mg for maintenance of maternal arterial pressure. The indication for administration of vasopressor was a reduction in systolic pressure to < or = 90% of baseline values. Maternal arterial pressure (BP) and heart rate (HR) were measured every minute by automated oscillometry. Cardiac output (CO) was measured by cross-sectional and Doppler echocardiography before and after preloading with 1500 ml Ringer lactate solution and then every 2 min after administration of bupivacaine. Umbilical artery pulsatility index (PI) was measured using Doppler before and after spinal anaesthesia. The median (range) number of boluses of phenylephrine and ephedrine was similar; 6 (1-10) vs 4 (1-8) respectively. Maternal systolic BP and CO changes were similar in both groups, but the mean [95% CI] maximum percentage change in maternal HR was larger in the phenylephrine group (-28.5 [-24.2, -32.9]%) than in the ephedrine group (-14.4 [-10.6, -18.2]%). As a consequence atropine was required in 11/19 women in the phenylephrine group compared with 2/19 in the ephedrine group (P < 0.01). Mean umbilical artery pH [95% CI] was higher in the phenylephrine group (7.29 [7.28-7.30]) than in the ephedrine group (7.27 [7.25-7.28]). The results of the present study support the use of phenylephrine for maintenance of maternal arterial pressure during spinal anaesthesia for elective Caesarean section.

Markers of acute and chronic asphyxia in infants with meconium-stained amniotic fluid

OBJECTIVE: Cord blood pH, lactate, hypoxanthine, and erythropoietin levels has all been used as markers of either acute or chronic asphyxia. We sought to determine whether these index values were significantly different in infants with or without meconium-stained amniotic fluid. STUDY DESIGN: Fifty-six pregnant women in spontaneous labor at term were divided into two groups on the basis of the presence or absence of meconium-stained amniotic fluid. All meconium-stained fluid was centrifuged, and the volume percentage of particulate mater (i.e., meconium) was recorded. Umbilical artery blood and mixed arterial and venous cord blood were obtained at each delivery. Lactate, hypoxanthine, and erythropoietin levels were measured. Statistical analysis included Student t test and rank sum statistics where appropriate. Normal and Spearman correlation coefficients wer also used. RESULTS: There were no significant differences in mean umbilical artery pH 97.26 ± 0.06 vs 7.25 ± 0.10), lactate levels (32.8 ± 10 mg/dl vs 30.4 ± 14.2 mg/dl), and hypoxanthine levels (13.4 ± 6.7 μmol/L vs 14.0 ± 6.0 μmol/L) in newborns with meconium ( n = 28) compared with controls ( n = 26). Erythropoietin levels were significantly greater in newborns with meconium (median 39.5 mlU/ml vs 26.8 mlU/ml, p = 0.039). There was no correlation between the amount of particulate matter and any marker of asphyxia. CONCLUSIONS: There was no correlation between markers of acute asphyxia (i.e., umbilical artery blood pH, lactate, or hypoxanthine) and meconium. However, erythropoietin levels were significantly elevated in newborns with meconium-stained amniotic fluid. This latter marker may better correlate with chronic asphyxia.

Meconium in the Amniotic Fluid of Pregnancies Complicated by Preterm Premature Ruptureof Membranes Is Associated With Early Onset Neonatal Sepsis

Objective: This study was to determine the significance of meconium in the amniotic fluid of pregnancies complicated by preterm premature rupture of membranes (PPROM) without labor. Methods: A case-control study of 31 pregnancies complicated by PPROM at 27–36 weeks gestation with meconium present (study group) and 93 pregnancies complicated by PPROM but without meconium was performed. The patients were matched for year of delivery, gestational age, race, and parity. Pregnancy and neonatal outcome variables of the 2 groups were compared. Results: The incidence of early onset neonatal sepsis was significantly increased in the study group (16.1% vs. 1.1%; P < 0.001). Similarly, chorioamnionitis (48.3% vs. 22.5%; P < 0.01), cesarean delivery for a nonreassuring fetal heart rate pattern (19.4% vs. 3.2%; P < 0.01), a 5-min Apgar score < 7 (22.5% vs. 8.6%; P < 0.05), and fetal growth retardation (FGR) (12.9% vs. 2.2%; P < 0.05) were also more common in pregnancies complicated by PPROM with meconium. The mean umbilical cord arterial pH was significantly lower in these pregnancies (7.18 ± 0.07 vs. 7.28 ± 0.08; P < 0.001). After controlling for confounding variables with multiple logistic regression analysis, we found that meconium in the amniotic fluid remained associated with early onset neonatal sepsis. Conclusions: The presence of meconium in the amniotic fluid of pregnancies complicated by PPROM is associated with an increased incidence of early onset neonatal group B β-hemolytic streptococcus (GBBS) sepsis.

Spontaneous recovery after severe metabolic acidaemia at birth.

Twenty-two severely acidaemic babies (mean umbilical artery pH 7.00), born at term but not requiring resuscitation, were matched for gestational age, mode of delivery and birthweight with non-acidaemic infants. Skin-puncture pH, PCO2 and base deficit were measured at 1 h of age in the acidaemic group. Mean respiratory and heart rates at 30 and 60 min in the two groups were not significantly different. The improvement in pH and base deficit in the acidaemic group correlated with PCO2 at 1 h of age but not with respiratory rates, heart rates or birthweight. However, all four small-for-gestational age infants and one other showed a significantly smaller rise in pH (mean 0.09) compared with the others (mean 0.33). This was associated with a smaller fall in PCO2 and no change in base deficit and these babies were not identified by clinical observations at 1 h of age. Thus, clinical observations of respiratory and heart rates over the first hour of life did not distinguish babies born with severe metabolic acidaemia and did not identify babies who were less efficient at compensating for the acidaemia.

Prophylactic Amnioinfusion in Pregnancies Complicated by Oligohydramnios: A Prospective Study

Prophylactic amnioinfusion was assessed in term and post-dates pregnancies with decreased amniotic fluid volume. Subjects were randomly assigned to one of three groups: amnioinfusion with warmed saline solution, room-temperature saline, or control. Patients receiving prophylactic amnioinfusion had a significant decrease in both the frequency and severity of variable decelerations in the first stage of labor (P = .006) and in the average total number of variable decelerations in the first and second stages of labor (P = .01) compared with controls. There was no observed effect on newborn serum electrolyte levels with amnioinfusion, nor was there any apparent benefit of infusion of warmed saline compared with room-temperature saline. In contrast to premature gestations with oligohydramnios, prophylactic amnioinfusion was not associated with a significant improvement in mean umbilical arterial and venous pH or a significant decrease in cesarean delivery for fetal distress (P = .09). This is perhaps because the term fetus has an enhanced ability to tolerate recurrent episodes of heart rate decelerations without demonstrating the rapid metabolic changes seen in the premature fetus.

Dopplerflußverhalten in mütterlichen und fetalen Gefäßen vor und während Periduralanästhesie

26 women with an uneventful singleton pregnancy near term underwent scheduled Caesarean section with lumbar epidural anaesthesia (PDA). Doppler-flow measurements of the foetal umbilical artery and the maternal hypogastric artery were taken before and after sympathicolysis was established. The mean arterial blood pressure was maintained unchanged between the measurements. Both measurements were performed by the same examiner. Three patients received additional general anaesthesia during the operation because of inadequate analgesia. The resistance index (RI) with PDA decreased significantly in 23 patients by a mean of 7.6% (p less than 0.05). The RI in those patients (n = 3) with inadequate analgesia increased by a mean of 27%. The physiologically reversed diastolic flow in the maternal hypogastric artery was mathematically taken into consideration by applying the quotient of the systolic flow and the diastolic reversed flow (V/R-quotient). The V/R-quotient increased with established sympathicolysis by more than 180% in all but one patient. The neonates' mean umbilical artery pH was 7.32 (7.27 to 7.41), the mean five minute Apgar score was 10 (8 to 10).

Phenylephrine in the prevention of hypotension following spinal anesthesia for cesarean delivery

Study Objective: Phenylephrine and ephedrine were compared in the prevention of maternal hypotension following spinal anesthesia for elective cesarean delivery. Design: Randomized, double-blind trial. Setting: Obstetric suite at a university-affiliated hospital. Patients: Sixty healthy patients electively scheduled for cesarean delivery under spinal anesthesia. Interventions: Patients were randomly assigned to receive either ephedrine (n = 29) in 10 mg intravenous (IV) bolus injections or phenylephrine (n = 31) in 80 μg IV bolus injections to maintain systolic blood pressure (SBP) above 100 mmHg. Measurements and Main Results: Maternal venous, umbilical artery, and umbilical vein blood gases were measured, and neonatal Apgar scores and Early Neonatal Neurobehavior Scale scores were assessed. In the ephedrine group, umbilical artery pH was 7.28 ± 0.01 (mean ± SEM), umbilical artery partial pressure of carbon dioxide (PCO 2) was 56.6 ± 1.4 mmHg, and umbilical artery base deficit was 2.2 ± 0.04 meq. In the phenylephrine group, umbilical artery pH was 7.32 ± 0.01, umbilical artery PCO 2 was 52.1 ± 1.3 torr, and umbilical artery base deficit was 0.38 ± 0.35 meq. There were significant differences between the groups in mean umbilical artery pH, PCO 2 and base deficit, although all values obtained were within normal limits. There were no significant differences between the groups in the remaining acid-base values, neonatal Apgar scores, Early Neonatal Neurobehavior Scale scores, or frequency of maternal nausea and vomiting. Conclusions: Phenylephrine is as effective as ephedrine in the treatment of maternal hypotension, and when used in small incremental bolus injections, it appears to have no adverse neonatal effects in healthy, nonlaboring parturients.

Safety of term vaginal breech delivery

Of 247 women who were pregnant of one healthy child in breech presentation at term, 13 (5.3%) were delivered by a primary cesarean section. The other 234 (94.7%) were allowed to attempt vaginal birth. In these women, the only factor to determine the possibility of a vaginal delivery was normal progression of labor during the first stage, without secondary arrest or signs of fetal distress. 109 Women (44.1%) were delivered spontaneously according to Bracht, 87 (35.2%) had an assisted breech delivery, and 38 (15.4%) underwent a secondary cesarean section. There were two perinatal deaths (0.8%). One of them was directly related to the trial of labor. Two children with a birth trauma had an uneventful recovery. The 1 min Apgar score in all breech delivery groups was more often lower than in a control group of children, who were born spontaneously at term in vertex presentation. However, the 5 min Apgar score and the mean umbilical artery pH were within normal limits in all groups. The secondary cesarean section rate was inversely related to vaginal parity of the mother, and directly related to the newborns' birth weight. There was no relation between the secondary cesarean section rate and the type of breech presentation. It is concluded, that a trial of labor in carefully selected patients with a child in breech presentation at term is a safe procedure, that can be successfully completed in almost 80% of cases. In retrospect, low vaginal parity and high birth weight of the newborn have a negative influence on normal progression of labor.

Klinikinterne, individuelle Leistungserfassung und geburtshilfliche Qualitätssicherung

Obstetrical management and fetal outcome were individually analysed annually from 1987 to 1990, using computerised equipment. The individual results were discussed anonymously with all colleagues, but every colleague knew his own results. Clinical methods and obstetrical management had not been changed during the investigation period. The number of high-risk pregnancies increased significantly, whereby the incidence of risk-related surgical interventions decreased at the same rate. The number of FBA and EDA increased significantly (p less than 0.001). The mean umbilical artery pH increased during the last four years from 7.27 to 7.30 (p less than 0.05), i.e. that each colleague achieved an improvement. The incidence of acidotic values in the umbilical artery decreased significantly (pH less than 7.20 from 13.2% to 7.1%, pH less than 7.10 from 3.6% to 1.2% p less than 0.01). The rate of caesarean section increased (p less than 0.05) and the number of vaginal operative deliveries did not change significantly. As early as one year after the introduction of the individual efficiency control, a significant improvement in obstetrical results could be demonstrated.

Intrapartum asphyxia in pregnancies complicated by intra-amniotic infection

Intra-amniotic infection has been reported to be associated with intrapartum asphyxia; however, the criteria used to define asphyxia have been imprecise. In the present study of 123 women with intra-amniotic infection and 6769 women without infection, the mean umbilical artery pH was 7.28 in both groups. The frequency of acidemia (umbilical artery pH less than 7.20) was not significantly different between the infection group and controls (15 versus 10%; P = .12). Likewise, there was no significant difference between the groups when a lower umbilical artery pH value (less than 7.15) was used to define acidemia. None of the infants from infected mothers had metabolic acidemia with a pH of less than 7.15 and none had a pH of less than 7.00. Significantly more (P less than .05) infants in the infected group did have low 1-minute (20 versus 5%) and 5-minute (3 versus 1%) Apgar scores of 6 or less, criteria often used to define asphyxia. However, none of the newborns from the infected group had recently proposed criteria for the diagnosis of birth asphyxia (ie, leading to neurologic impairment) such as metabolic acidemia, seizures in the immediate newborn period, and low Apgar scores (3 or less). Birth asphyxia is rarely associated with intra-amniotic infection, and in the absence of other signs of fetal jeopardy such as an ominous fetal heart rate pattern, an immediate cesarean to prevent asphyxia does not appear justified once the diagnosis of chorioamnionitis is made.

Epidural Versus General Anaesthesia for Elective Caesarean Section Effect on Apgar Score and Acid-Base Status of the Newborn

Summary Elective Caesarean section deliveries over a 5-year period were studied to compare the effect of epidural block with general anaesthesia on the condition of the infant at birth. The Apgar score and umbilical arterial acid-base status were used as determinants of the latter. Epidural block was used in 139 (22.8%) mothers while 471 (77.2%) were performed under general anaesthesia. No babies in the epidural group were severely depressed (Apgar < 4), compared with 6.2% in the general anaesthesia group. Only 4.3% of the epidural sections were moderately depressed (Apgar 4–6), compared with 15.4% of the others. These differences remained highly significant when infants of less than 2500 g were excluded, and when matched groups were compared. Mean umbilical arterial pH was similar within the two groups (pH 7.28), and was not consistent with asphyxia in almost 90% of the depressed infants. The findings suggest that general anaesthesia, rather than asphyxia or aortocaval compression, is responsible for most of the depressed infants born by elective Caesarean section. This may involve over 20% of babies delivered in this manner, so greater use of epidural block for elective Caesarean section is recommended. Further investigations are required to improve results with general anaesthesia.

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.

The Northwestern University triplet study

Abstract 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, PCO 2 , 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.

A double blind quantitative study of the effects of meptazinol and pethidine on the fetal heart rate in labour

SummaryA double blind controlled trial was carried out to measure the effects of pethidine and meptazinol on the fetal heart rate in labour. Patients who selected epidural or inhalational analgesia were used as controls.The fetal heart rate was analysed numerically, using a microcomputer, for 45-60 min before and after drug administration to allow for fetal behavioural state changes. Controls showed no change in heart rate or its variation over two successive periods of observation.The mean numbers of accelerations (> 10 beats per min and 15 s duration) were reduced by 46 per cent (P < 0.001) with pethidine administration and by 33 per cent (p < 0.05) with meptazinol. The reduction in overall fetal heart rate variation with pethidine was only 20 per cent (P < 0.05); no change was demonstrated with meptazinol.The mean umbilical artery pH at delivery was 7.28 in the meptazinol babies, higher than the mean of 7.22 in the controls (P<0.05), but no other differences in the blood gas values were found.

Transcutaneous carbon dioxide measurements in the fetus during labor.

Continuous transcutaneous carbon dioxide partial pressure (tcPco2) was monitored in 40 spontaneous labors. The electrode was attached by glue fixation. An interpretable tracing was obtained in 36 cases. All cases but 2 were normal pregnancies. Thirty-two patients had epidural analgesia while the others had no analgesia. All infants had an Apgar score above 7 at five minutes after delivery and only two had a pH of the umbilical artery of less than 7.16. Mean duration of the recordings was 116 minutes (range: 15-300) and mean time for reaching steady-state was 27 minutes (range: 10-45 minutes). Mean value of tcPco2 was 48 mmHg (SD: 6) before 6 cm of dilatation, 47 mmHg (SD: 8) between 6 and 10 cm, and 47 mmHg (SD: 15) at the second stage of labor. Mean umbilical artery Pco2 was 48 mmHg (SD: 14) and mean umbilical artery pH was 7.25 (SD: 0.06). The range of tcPco2 obtained in these normal cases was 20 to 62 mmHg. Comparison of the results with those of other authors and with previous studies of normal labor and epidural analgesia show a higher tcPco2 compared to scalp Pco2. In contrast to other studies in these series no correlation was found in the series between umbilical artery Pco2 and tcPco2 values. This lack of correlation could be explained either by the small number of cases in which both measurements were available (9 cases) and by the small range of variation or by some inaccuracy in the measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

CORD PLASMA HYPOXANTHINE (HX ), VASOPRESSIN (AVP), AND ERYTHROPOIETIN (EP) AS PARAMETERS OF ACUTE BIRTH ASPHYXIA

The Apgar score correlates poorly with metabolic acidosis at birth. We evaluated the relationship of these 2 parameters to 3 other indices of asphyxia, cord plasma HX, AVP, and EP concentrations, in infants born with acute asphyxia after normal pregnancy. During a 2-month period, at 972 consecutive deliveries, the umbilical cord was doubly clamped immediately after birth. 16 infants had an Apgar score of ≤6 at 5 min (group A). Their mean umbilical arterial (UA) pH was 7.18; only 3 had a pH ≤7.05. 17 infants had an UA-pH of ≤7.05 (group B). Log mean of UA-HX was 15 ymol/1 in group A (n=8) and 32 ymol/1 in group B (n=10). In both groups combined, UA-pH and HX were significantly correlated (r=-0.57). Log mean of UA-AVP was 79 pg/ml in group A (n=5), and 603 pg/ml in group B (n=9). In both groups combined, UA-pH and AVP (r=-0.76) and HX and AVP (r=0.55) were correlated. Log mean of UV-EP was 32 mU/ml in group A (n=8) and 44 mU/ml in group B (n=13). UA-pH and UV-EP, nor any of the parameters and Apgar score were correlated. We conclude that UA-pH, HX, and AVP are related indices of acute birth asphyxia, defining a risk group different from that defined by Apgar score UV-EP does not reflect acute asphyxia, which is in line with the known delay between a hypoxic insult and EP response.