Cord Blood Acid-base Research Articles

Delayed umbilical cord clamping at birth has effects on arterial and venous blood gases and lactate concentrations

To estimate the influence of delayed umbilical cord clamping at birth on arterial and venous umbilical cord blood gases, bicarbonate (HCO3-), base excess (BE) and lactate in vigorous newborns. University hospital. Prospective observational. Vaginally delivered term newborns. Umbilical cord arterial and venous blood was sampled repeatedly every 45 seconds (T(0)= time zero; T(45)= 45 seconds, T(90)= 90 seconds) until the cord pulsations spontaneously ceased in 66 vigorous singletons with cephalic vaginal delivery at 36-42 weeks. Longitudinal comparisons were performed with the Wilcoxon signed-ranks matched pairs test. Mixed effect models were used to describe the shape of the regression curves. Longitudinal changes of umbilical cord blood gases and lactate. In arterial cord blood, there were significant decreases of pH (7.24-7.21), HCO3- (18.9-18.1 mmol/l) and BE (-4.85 to -6.14 mmol/l), and significant increases of PaCO(2) (7.64-8.07 kPa), PO(2) (2.30-2.74 kPa) and lactate (5.3-5.9 mmol/l) from T(0) to T(90), with the most pronounced changes at T(0)-T(45). Similar changes occurred in venous blood pH (7.32-7.31), HCO3- (19.54-19.33 mmol/l), BE (-4.93 to -5.19 mmol/l), PaCO(2) (5.69-5.81 kPa) and lactate (5.0-5.3 mmol/l), although the changes were smaller and most pronounced at T(45)-T(90). No significant changes were observed in venous PO(2). Persistent cord pulsations and delayed cord clamping at birth result in significantly different measured values of cord blood acid-base parameters.

Cord blood thyroid-stimulating hormone level and risk of acidosis at birth

Objective Cord blood thyroid-stimulating hormone level is elevated in neonates who had undergone more perinatal stresses. The present study aimed to evaluate the cord blood acid–base status in neonates with elevated thyroid-stimulating hormone level. Study design The study population consisted of 2366 singleton, term pregnancies. Subjects were categorized by their cord blood thyroid-stimulating hormone level into four quartiles, and cord blood acid–base parameters were compared among the four groups. The correlations between cord acid–base parameters and thyroid-stimulating hormone level were also studied. Results Cord blood pH was significantly lower in the highest (arterial, 7.27 ± 0.08; venous, 7.32 ± 0.07) and second highest thyroid-stimulating hormone quartile groups (arterial, 7.29 ± 0.07; venous, 7.34 ± 0.06) compared to the lowest quartile group (arterial, 7.30 ± 0.06; venous, 7.35 ± 0.05). Incidences of cord arterial pH ≤7.20 were 4.7%, 6.8%, 10.9%, and 17.3% in lowest to the highest thyroid-stimulating hormone quartile groups, respectively. There was a significant negative correlation between cord blood thyroid-stimulating hormone level and cord arterial and venous pH ( r = −0.26, P < 0.001). When stratified according to the mode of delivery, the negative correlations remained significant in neonates delivered vaginally and by intrapartum emergency cesarean section but not in neonates delivered by elective cesarean section. Conclusion Incidence of cord blood acidosis is significantly higher in neonates with elevated thyroid-stimulating hormone level. This findings support the postulation that stress-induced elevation of cord blood thyroid-stimulating hormone level may be mediated through intrapartum fetal hypoxia.

Cord blood acid-base status at delivery after successful external cephalic version.

This study was designed to evaluate whether cord blood acidosis is more likely in infants born after successful external cephalic version. This retrospective cohort study included 89 singleton deliveries with successful version performed over a 2-year period. Their cord blood acid-base parameters were compared to 89 pregnancies with spontaneous cephalic presentation (control group). There was no significant difference between the version and control groups in birthweight and Apgar scores. There was no difference between the version and control groups in cord arterial pH (7.26 vs. 7.26), arterial pCO(2) (7.04 vs. 7.09 kPa), arterial pO(2) (2.34 vs. 2.59 kPa), arterial base excess (-5.59 vs. -5.64 mmol/L), venous pH (7.32 vs. 7.33), venous pCO(2) (5.73 vs. 5.63 kPa), venous pO(2) (3.86 vs. 3.84 kPa), or venous base excess (-5.03 vs. -5.12 mmol/L). There was also no significant difference in the number of fetuses with cord arterial pH <7.20 between the two groups. Neonates delivered after successful external cephalic version are not more likely to be born with acidosis. Our study provides further support for the safety of external cephalic version for term breech pregnancies.

Cord blood acid-base status at delivery after successful external cephalic version

Cord blood acid-base status at delivery after successful external cephalic version

Vaginal breech delivery: is it still an option?

Objective: To provide local data on term breech delivery for future guidance. Study design: Retrospective, ‘intended-mode-of-delivery’ analysis of 711 antenatally uncomplicated singleton breech deliveries at ≥37 weeks: 445 (63%) planned for vaginal delivery (VD) (no fetal growth restriction, fetal weight 2000–4000 g, adequate pelvic size, maternal consent) and 266 for cesarean section (CS). Outcome measures: Apgar score, cord blood acid–base status, childhood deaths and disability. Results: Perinatal mortality was nil in both groups. Low 1-min Apgar scores and low arterial cord blood pH were significantly more frequent in planned VD, but not low Apgar scores at 5 or 10 min or low venous pH. Metabolic acidosis, neonatal intensive care, neonatal seizures, birth trauma, childhood death (CS=1), and neurodevelopmental handicaps (CS=2, VD=1) were equally common. Conclusion: Our results do not disqualify selective vaginal breech delivery at term and beyond as an option.

Lipid peroxidation, antioxidant defence and acid-base status in cord blood at birth: the influence of diabetes.

Pregnancy complicated by poor control of diabetes is associated with a higher risk of embryopathies, spontaneous abortions and perinatal mortality. A number of authors suggest an involvement of reactive oxygen species (ROS) in diabetic pregnancy. Determining lipid peroxidation products (LP), scavenging enzyme activities and the umbilical cord blood's acid-base balance may contribute to an adequate diagnosis of the neonate at birth. Nevertheless, such measurements seem to have limited value in practical clinical routine. The present study evaluates LP, antioxidant defence and acid-base status related to diabetic pregnancy. Twenty-eight women with type 1 diabetes (PGDM), 19 with gestational diabetes (GDM) and 13 control cases were investigated. An additional control group consisted of 15 healthy patients with negative diabetic history; all women underwent vaginal delivery. Immediately after delivery cord blood samples and placental tissue were collected for malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) determination. Additionally, pH, pCO2, pO2 and base excess were measured in both vessels and compared to identify and exclude double venous samples. MDA levels in both cord blood and placental homogenates were significantly higher in both pregestational and gestational diabetic groups, but SOD activity was significantly diminished. Cord blood GSH was markedly elevated in PGDM and GDM. We have also shown significant differences in acid-base parameters in infants of PGDM group. Statistical analysis was performed using the Mann-Whitney U-test. These findings indicate an excessive oxidative stress in pregnancy complicated by diabetes mellitus. Evaluating LP products and scavenging enzyme activities may be valuable, sensitive indexes of fetal/neonatal threat in diabetic pregnancy in humans. Since oxidative stress is an important pathway for fetal injury, we believe that obtaining adequate measurements at the time of birth would contribute to clarifying the fetal/neonatal status in a medical and legal context and might be of value in altering therapy in newborn infants.

Lipid peroxidation in umbilical arterial blood at birth: the effects of breech delivery.

To determine oxygen free radical activity in breech presentation at birth and relate it to umbilical cord blood acid-base status. A series of 63 singleton deliveries (28 cephalic deliveries as controls), 23 breech deliveries with normoacidemia, and 12 breech deliveries with mild acidaemia) had determination of malondialdehyde and acid-base parameters. The delivery suite in the Department of Obstetrics and Gynaecology at the Süleyman Demirel University, Isparta, Turkey. Sixty-three singleton infants born at term with spontaneous or induced labour and initially normal fetal heart rate tracing. After delivery, umbilical cord arterial and venous blood samples were collected for the determination of malondialdehyde concentrations. Oxygen saturation, pO2, pCO2, pH, and base excess were also measured. Umbilical cord arterial and venous blood gases and malondialdehyde levels. There was a significant correlation between umbilical arterial and venous levels of malondialdehyde and all acid-base parameters (P < 0.001). There were negative correlations between malondialdehyde levels and pH, pO2 and bicarbonate, while there was a positive correlation between malondialdehyde concentrations and pCO2. A positive correlation between malondialdehyde levels and base excess was present in the control group and total breech group (n = 35). The malondialdehyde levels in the total breech group, nonacidaemic breech group (n = 23) and the mildly acidaemic breech group (n = 12) were significantly higher than those in the control group (P < 0.0001). However, acid-base parameters in the nonacidaemic breech group were not statistically different from those in the control group. Lipid peroxidation products (malondialdehyde) existed to some extent in the umbilical cords of newborns with normal acid-base parameters in breech delivery. Our data support the contention that lipid peroxide may be a more sensitive measure for metabolic dysfunctions due to fetal hypoxia than acid-base balance.

The association between oxidative stress and umbilical cord blood acid-base status during delivery

International Journal of Gynecology & ObstetricsVolume 70, Issue S2 p. B121-B121 Fetal monitoring/programming The association between oxidative stress and umbilical cord blood acid-base status during delivery A. Bobakova, A. BobakovaSearch for more papers by this authorM. Simko, M. SimkoSearch for more papers by this authorP. Blazicek, P. BlazicekSearch for more papers by this authorI. Holly, I. HollySearch for more papers by this authorD. Syrova, D. SyrovaSearch for more papers by this author A. Bobakova, A. BobakovaSearch for more papers by this authorM. Simko, M. SimkoSearch for more papers by this authorP. Blazicek, P. BlazicekSearch for more papers by this authorI. Holly, I. HollySearch for more papers by this authorD. Syrova, D. SyrovaSearch for more papers by this author First published: 10 December 2003 https://doi.org/10.1016/S0020-7292(00)83077-5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume70, IssueS22000Pages B121-B121 RelatedInformation

Concentration of Purine Metabolites in Birth Asphyxia: Correlation with Cord Blood Acid Base Changes

Concentration of Purine Metabolites in Birth Asphyxia: Correlation with Cord Blood Acid Base Changes

Umbilical cord blood gas analysis in augmented labour

Labour augmentation with oxytocin may produce an excessive increase in frequency, duration or strength in uterine contractions which may result in fetal stress. Umbilical cord acid-base assessment provides an objective parameter in evaluating the neonatal condition immediately after delivery. We evaluated the neonatal condition in 235 deliveries where oxytocin was used for labour augmentation. The umbilical cord blood acid-base status was correlated with intrapartum cardiotocographic findings and Apgar scores. In two cases we noted umbilical artery pH <7.05 but the BDecF was not higher than 11 mmol/l and the 5-minute Apgar score was 8 in all cases. Our results indicate that the use of oxytocin for labour augmentation had no adverse effects on neonatal condition.

Umbilical cord blood acid‐base values in uncomplicated termvaginal breech deliveries

This prospective study was conducted to compare the umbilical cord blood acid-base values of uncomplicated, assisted, vaginal-breech-delivery term neonates with those of uncomplicated, cephalic-vaginal delivery term neonates and to determine whether a different metabolic status should be expected in neonates born by way of uncomplicated vaginal breech delivery. Umbilical cord artery and vein blood samples were obtained from 30 term neonates with frank or complete breech presentations who were born by uncomplicated assisted vaginal breech delivery. All these neonates had an Apgar score of >7 at 5 min and an uneventful neonatal course (study group). For each neonate in the study group the two consecutive term neonates who were delivered by uncomplicated cephalic spontaneous vaginal delivery, and had uneventful neonatal courses, served as controls (control group). The umbilical cord artery blood pH and pO2 were significantly lower (p<0.001 and <0.01, respectively) and the pCO2 was significantly higher (p<0.001) in newborns of the study group, compared to the controls. The umbilical cord vein blood pH was significantly lower (p<0.01), and the pCO2 significantly higher (p<0.01) in the study group. The umbilical cord blood acid-base values of uncomplicated, vaginal-breech-delivery term neonates differ significantly from those of uncomplicated, cephalic-vaginal delivery neonates. These differences may represent a greater degree of acute cord compression that reflects the different mechanisms of labor in vaginal breech delivery.

Umbilical cord blood acid-base values in uncomplicated termvaginal breech deliveries

Umbilical cord blood acid-base values in uncomplicated termvaginal breech deliveries

Perinatal factors predicting severe intracranial hemorrhage.

The objective of this paper is to determine the importance of perinatal factors predicting occurrence of severe intracranial hemorrhage (ICH) in premature newborns. A post-hoc analysis of a previously published randomized, double-blinded, prospective trial was performed. Logistic regression analysis was used to assess the importance of obstetrical variables and umbilical cord blood coagulation studies and acid-base status in predicting severe ICH (grades 3 and 4). The trial lasted 42 months; 401 pregnant women were invited to participate and 48 declined. The most important predictors of severe ICH in order of decreasing significance were: gestational age at delivery (p=0.0001), duration of painful labor (p=0.0077), duration of antenatal antibiotic therapy (p=0.0203), maternal age (p=0.0247), and factor X activity in umbilical cord blood (p=0.0302). Mode of delivery, cord blood acid-base, and coagulation status did not correlate with severe ICH. The majority of severe ICHs were late in onset; only two of 31 were known to have occurred in the first 24 hr of life. Gestational age, duration of painful labor, duration of antibiotic therapy, and maternal age were the most important predictors of severe ICH.

The etiology of fetal acidosis as determined by umbilical cord acid-base studies

OBJECTIVE: Our purpose was to determine whether umbilical cord acid-base values might be used to differentiate abruptio placentae from cord prolapse. STUDY DESIGN: By use of a retrospective study design, umbilical cord blood acid-base values of 32 cases of severely acidotic acute abruptio placentae were statistically compared with those of 19 cases of severely acidotic acute cord prolapse with Fisher's exact test, Mann-Whitney U tests, and receiver-operator curve characteristic analyses. RESULTS: No significant differences in electronic fetal heart rate record interpretations were detected. Highly significant differences in umbilical arterial and umbilical venous blood gas values were noted between the two groups. Most notable were the differences between umbilical venous and arterial blood gas values in the cord prolapse group. Receiver-operator characteristic curve analysis demonstrated that an umbilical venous-arterial pH difference of 0.15 was an effective cutoff value in differentiating cord prolapse from abruptio placentae (accuracy 92%). CONCLUSION: Umbilical arterial blood gas values combined with umbilical venous blood gas values can assist in determining the pathogenesis of marked fetal acidosis. (Am J Obstet Gynecol 1997;177:274-82.)

Umbilical cord blood sampling--a tool for delivery quality control?

Regular cord blood analysis post partum is regarded by many as one of the most accurate and objective methods of auditing intrapartum care. Emergency cesarean sections and ventouse deliveries, due to the threat of asphyxia, are examples where post partum acid base data from the umbilical artery ought to be a must. The possibility of having cord blood analyses as a routine at all deliveries was investigated in this study. During a two month period blood samples were drawn from both the umbilical artery and vein at all vaginal deliveries and cesarean sections between 8 am and 4 pm. Samples were analysed for a complete acid base status and lactate concentration. True paired artery-venous samples for acid base data and lactate concentrations were obtained from 48% of the women. Sampling was especially difficult after emergency cesarean section and vaginal twin deliveries. Lactate analyses gave the same information about the metabolic state of the newborn as did BEecf. Cord blood acid base data are a superior method of retrospective analyses of CTG-tracings and partographs within a quality control program relating to intra partum care. However, routines for cord blood sampling must be well established in both the delivery room and in the operating theater to obtain samples from the umbilical artery in cases of threatening intrapartum asphyxia. A graph for easy post partum documentation and interpretation of acid base data is introduced.

Oral Administration of Misoprostol for Labor Induction

In Brief Objective To evaluate the effectiveness, safety, and gastrointestinal tolerance of misoprostol taken orally for induction of labor, against our established protocol, with the interval from induction to vaginal birth as the primary outcome measure. Methods Two hundred seventy-five women who presented with indication for induction of labor were assigned randomly to receive either 50 μg of misoprostol orally every 4 hours as needed or treatment according to our established protocol (physician-chosen combinations of intracervical or vaginal prostaglandins every 4–6 hours, artificial rupture of membranes, and oxytocin infusion). Sample size was calculated with a two-tailed alpha = .05 and power of 95%. Results The mean time (± standard deviation) to vaginal birth with oral misoprostol was 926 ± 521 minutes versus 909 ± 585 minutes with the established protocol, a nonsignificant difference. There were no clinically or statistically significant differences in maternal secondary outcome measures (cesarean rate, frequency of epidural use, perineal trauma, or manual removal of the placenta). There was no difference in frequency of maternal gastrointestinal side effects. Neonatal outcomes, including cord blood acid-base analysis, were not different. Conclusions Oral misoprostol may be a new option for labor induction. It appears to be no less effective or safe than our usual regimen for induction of labor at term and is well tolerated. Further studies are warranted to confirm the safety of this approach and to determine optimal dose and frequency of administration. Oral adminstration of misoprostol is effective as a method of labor induction and has no adverse maternal or fetal side effects.

Oral administration of misoprostol for labor induction: A randomized controlled trial

To evaluate the effectiveness, safety, and gastrointestinal tolerance of misoprostol taken orally for induction of labor, against our established protocol, with the interval from induction to vaginal birth as the primary outcome measure. Two hundred seventy-five women who presented with indication for induction of labor were assigned randomly to receive either 50 micrograms of misoprostol orally every 4 hours as needed or treatment according to our established protocol (physician-chosen combinations of intracervical or vaginal prostaglandins every 4-6 hours, artificial rupture of membranes, and oxytocin infusion). Sample size was calculated with a two-tailed alpha = .05 and power of 95%. The mean time (+/-standard deviation) to vaginal birth with oral misoprostol was 926 +/- 521 minutes versus 909 +/- 585 minutes with the established protocol, a nonsignificant difference. There were no clinically or statistically significant differences in maternal secondary outcome measures (cesarean rate, frequency of epidural use, perineal trauma, or manual removal of the placenta). There was no difference in frequency of maternal gastrointestinal side effects. Neonatal outcomes, including cord blood acid-base analysis, were not different. Oral misoprostol may be a new option for labor induction. It appears to be no less effective or safe than our usual regimen for induction of labor at term and is well tolerated. Further studies are warranted to confirm the safety of this approach and to determine optimal dose and frequency of administration.

Umbilical cord blood gas analysis at the time of delivery

Aims: it is now recommended that cord blood acid-base measurement is performed routinely at time of delivery in the UK as a measure of fetal response to labour. However, there remains some uncertainty about the value of this procedure. In this paper our experience of cord blood analysis is described and the literature is reviewed to: (1) provide an overview of the physiological basis of cord blood acid-base assessment; (2) describe the appropriate methodology and identify issues which have contributed to confusion and undermined the value of cord blood sampling; and (3) address the practical issues of cord blood sampling. Conclusions: cord blood acid-base measurement has a sound physiological basis. It provides objective information which is a useful adjunct to subjective methods of newborn assessment, enables babies at risk of neonatal morbidity to be identified, can be helpful in litigation cases and is a prerequisite for clinical audit. However, to be of benefit the information must be correct and correctly interpreted.

Fetal effects of prophylactic ephedrine and maternal hypotension during regional anesthesia for cesarean section

The purpose of this study was to evaluate the effects of a prophylactic intravenous bolus of ephedrine on the incidence and severity of maternal hypotension and on neonatal outcome. Term healthy parturients (n = 122) scheduled for elective repeat cesarean section under regional anesthesia were studied. Ninety-two women received 10 mg ephedrine as a prophylactic intravenous bolus prior to intrathecal epidural local anesthesia. Thirty parturients who served as controls did not receive prophylactic ephedrine. Maternal blood pressures, Apgar scores, and umbilical cord blood acid-base status were evaluated. Sixty-three of 92 women (69%) who received intravenous prophylactic ephedrine prior to regional anesthesia developed hypotension compared to 21 (70%) controls. The mean (+/- SD) lowest systolic blood pressure was similar in both groups (95.6 +/- 12.9 vs. 96 +/- 8.9 mmHg; P = 0.86). The mean (+/-SD) fetal pH was significantly lower with prophylactic ephedrine than controls (7.24 +/- 0.07 vs. 7.28 +/- 0.05; P = 0.001). The frequency of umbilical artery blood pH < 7.20 was 10.6% for the ephedrine group vs. 3.2% for controls (P = 0.024). Among newborns of hypotensive mothers, the frequency of umbilical artery blood pH < 7.20 was 30.2% and 4.6% for the ephedrine and control groups, respectively (P = 0.018). Intravenous prophylaxis with ephedrine did not significantly decrease the frequency of hypotension in women receiving regional anesthesia and resulted in a greater proportion of umbilical artery blood pH values < 7.20.

Effect of vacuum extraction on umbilical cord blood acid‐base measurements

The objective of this study was to determine whether vacuum extraction is associated with umbilical cord blood acid-base changes when used electively or in the presence of suspected fetal distress. Data from 1,428 patients from a previously published randomized trial of intrapartum electronic fetal heart rate monitoring versus intermittent auscultation were analyzed to identify differences in umbilical cord blood acid-base measurements associated with the elective use of vacuum extraction (patients with duration of second stage of labor 60 min or less) and also in the presence of suspected fetal distress during the second stage of labor. When used electively, vacuum extraction was associated with lower pH (in both umbilical cord artery and vein), lower venous base excess, and higher venous carbon dioxide tension (PCO2), as compared to normal spontaneous vaginal delivery. After correcting for duration of second stage of labor, elective vacuum delivery was significantly associated only with a decrease in cord venous pH and increase in venous PCO2. However, these cord blood acid-base changes were not accompanied by any differences in perinatal morbidity and mortality or in the number of neonates born with acidemia (cord arterial pH <7.15 or <7.10). In cases of suspected fetal distress, the use of vacuum extraction was not associated with any detectable cord blood acid-base changes as compared to normal spontaneous vaginal delivery. These data support the continued use of vacuum extraction, especially in cases of suspected fetal distress during the second stage of labor. © 1996 Wiley-Liss, Inc.