Cord Blood Gas Research Articles

Umbilical Cord Blood Gas Pairs with Near-Identical Results: Probability of Arterial or Venous Source.

In studies of concomitant arterial-venous umbilical cord blood gases (CAV-UBGs), approximately 10% of technically valid samples have very similar pH and/or pCO2 values and were probably drawn from the same type of blood vessel. Without a way to objectively determine the source in these cases, it has been argued that most of these same-source CAV-UBGs are venous because the vein is larger and more easily sampled than the artery. This study aimed to calculate the probability of an arterial (ProbAS) or venous source (ProbVS) of same-source CAV-UBGs in the clinically and medicolegally important pH range of 6.70 to 7.25 using a statistical predictive model based on the cord blood gas values. Starting with a dataset of 56,703 CAV-UBGs, the ProbAS, ProbVS, and respective 95% confidence intervals (CIs) were calculated for the 241 sample pairs with near-identical pH, pCO2, and pO2 values and a pH of 6.70 to 7.25. Using a previously validated generalized additive model, the source was categorized as: Probable Arterial or Highly Probable Arterial if the ProbAS and CIs were >0.5 or >0.8, respectively; Probable Venous or Highly Probable Venous if the ProbVS and CIs were >0.5 or >0.8, respectively; or Indeterminant if the CIs encompassed ProbAS/VS = 0.5. A total of 39% of the same-source CAV-UBGs were Probable Arterial, 56% were Probable Venous, and 5% were Indeterminant. However, considering samples with a pH ≤7.19, 80% were Probable Arterial and 16% were Probable Venous. Considering the Highly Probable categories, the more acidemic specimens were 9 times more likely to be arterial than venous. Similarly, CAV-UBGs with pCO2 > 8.2 kPa (62 mm Hg) or pO2 ≤ 1.9 kPa (14 mm Hg) were more likely to be in the arterial rather than the venous categories. Same-source CAV-UBGs in the more acidemic, hypercarbic, or hypoxemic ranges are more likely to be arterial than venous. · Umbilical cord arterial/venous gases (CAV-UBGs) with similar values are thought to be mainly venous.. · A validated statistical model was used to predict the probability an arterial or venous source.. · CAV-UBGs with very similar values and pH > 7.19 are likely venous; however, those with pH ≤ 7.19 and/or pCO2 > 8.2 kPa and/or pO2 ≤1.9 kPa are more likely arterial..

Fetal Oxygenation from the 23rd to the 36th Week of Gestation Evaluated through the Umbilical Cord Blood Gas Analysis.

The embryo and fetus grow in a hypoxic environment. Intrauterine oxygen levels fluctuate throughout the pregnancy, allowing the oxygen to modulate apparently contradictory functions, such as the expansion of stemness but also differentiation. We have recently demonstrated that in the last weeks of pregnancy, oxygenation progressively increases, but the trend of oxygen levels during the previous weeks remains to be clarified. In the present retrospective study, umbilical venous and arterial oxygen levels, fetal oxygen extraction, oxygen content, CO2, and lactate were evaluated in a cohort of healthy newborns with gestational age < 37 weeks. A progressive decrease in pO2 levels associated with a concomitant increase in pCO2 and reduction in pH has been observed starting from the 23rd week until approximately the 33-34th week of gestation. Over this period, despite the increased hypoxemia, oxygen content remains stable thanks to increasing hemoglobin concentration, which allows the fetus to become more hypoxemic but not more hypoxic. Starting from the 33-34th week, fetal oxygenation increases and ideally continues following the trend recently described in term fetuses. The present study confirms that oxygenation during intrauterine life continues to vary even after placenta development, showing a clear biphasic trend. Fetuses, in fact, from mid-gestation to near-term, become progressively more hypoxemic. However, starting from the 33-34th week, oxygenation progressively increases until birth. In this regard, our data suggest that the placenta is the hub that ensures this variable oxygen availability to the fetus, and we speculate that this biphasic trend is functional for the promotion, in specific tissues and at specific times, of stemness and intrauterine differentiation.

Timely Detection of Infants at Risk of Intrapartum Acidosis and Hypoxic-Ischemic Encephalopathy Using Cardiotocography.

This work aims to improve the intrapartum detection of fetuses with an increased risk of developing fetal acidosis or hypoxic-ischemic encephalopathy (HIE) using fetal heart rate (FHR) and uterine pressure (UP) signals. Our study population comprised 40,831 term births divided into 3 classes based on umbilical cord or early neonatal blood gas assessments: 374 with verified HIE, 3,047 with acidosis but no encephalopathy and 37,410 healthy babies with normal gases. We developed an intervention recommendation system based on a random forest classifier. The classifier was trained using classical and novel features extracted electronically from 20-minute epochs of FHR and UP. Then, using the predictions of the classifier on each epoch, we designed a decision rule to determine when to recommended intervention. Compared to the Caesarean rates in each study group, our system identified an additional 5.68% of babies who developed HIE (54.55% vs 60.23%, p < 0.01) with a specific alert threshold. Importantly, about 75% of these recommendations were made more than 200 minutes before birth. In the acidosis group, the system identified an additional 17.44% (37.15% vs 54.59%, p < 0.01) and about 2/3 of these recommendations were made more than 200 minutes before birth. Compared to the Caesarean rate in the healthy group, the associated false positive rate was increased by 1.07% (38.80% vs 39.87%, p<0.01).Clinical Relevance- This method recommended intervention in more babies affected by acidosis or HIE, than the intervention rate observed in practice and most often did so 200 minutes before delivery. This was early enough to expect that interventions would have clinical benefit and reduce the rate of HIE. Given the high burden associated with HIE, this would justify the marginal increase in the normal Cesarean rate.

Evaluation of fetal acidemia during delivery using the conventional 5-tier classification and Rainbow systems.

The association between prepartum time-series fetal heart rate pattern changes and cord blood gas data at delivery was examined using the conventional 5-tier classification and the Rainbow system for 229 female patients who delivered vaginally. They were classified into three groups based on the results of umbilical cord blood gas analysis at delivery. The fetal heart rate pattern classifications were based on analysis of measurement taken at 10-min intervals, beginning at 120 min pre-delivery. The relationship between fetal heart rate pattern classification and cord blood pH at delivery changed over time. The 5-tier classification at each interval increased before delivery in the Mild and Severe groups compared with the Normal group. No significant differences were observed between acidemia groups. The Rainbow classification showed a significant differences between the acidemia groups at each interval, particularly during the prepartum period. A relationship between classification and outcome was evident before delivery for both the 5-tier classification and Rainbow system.

Effect of initial anesthetic technique on fetal cord blood gas pH for cesarean deliveries performed for the indication of fetal heart rate abnormalities

Background We hypothesized that parturients who had general anesthesia as the initial anesthetic technique for cesarean deliveries performed for fetal heart rate abnormalities would have a lower fetal cord blood gas pH compared to parturients who had regional anesthesia as the initial anesthetic technique. Methods We searched our electronic medical record for patients who had cesarean deliveries for the indication of fetal heart rate abnormalities from July 1, 2019, to June 30, 2021, at our hospital. An obstetrics resident and a maternal fetal medicine physician determined if the fetal heart tracing was category 2 or 3. Results A total of 130 and 29 patients with category 2 and 3 fetal heart tracing had regional and general anesthesia as the initial anesthetic technique, respectively. Fourteen and 20 patients with a category 3 fetal heart tracing had regional and general anesthesia as the initial anesthetic techniques, respectively. There were no differences in fetal cord blood gas pH between patients who had regional or general anesthesia as the first attempted anesthetic technique when patients with category 2 and 3 tracings were evaluated separately. Conclusion The initial anesthetic technique attempted for cesarean delivery was not associated with a worse fetal cord blood gas pH.

Neonatal serial creatinine levels as an adjunct biomarker in timing of fetal neurologic injury.

To investigate the rise and clearance of newborn creatinine in perinatal asphyxia as an adjunct biomarker to support or refute allegations of acute intrapartum asphyxia. In this retrospective chart review, newborns >35 weeks gestational age were evaluated from closed medicolegal cases of confirmed perinatal asphyxia and reviewed for causation. Data collected included newborn demographic data, patterns of hypoxic ischemic encephalopathy, brain magnetic resonance imaging, Apgar scores, cord and initial newborn blood gases, and serial newborn creatinine levels during the first 96h of life. Newborn serum creatinine values were collected at 0-12, 13-24, 25-48, and 49-96h. Newborn brain magnetic resonance imaging was used to define 3 patterns of asphyxial injury: acute profound, partial prolonged, or Both. Two hundred and eleven cases of neonatal encephalopathy from multiple institutions were reviewed from 1987 to 2019 with only 76 cases having serial creatinine values during the first 96h of life. A total of 187 creatinine values were collected. Partial prolonged and Both had significantly greater degree of metabolic acidosis in the first newborn arterial blood gas in comparison to acute profound. Acute profound and Both had significantly lower 5- and 10- minute Apgar scores in comparison to partial prolonged. Newborn creatinine values were stratified by asphyxial injury. Acute profound injury showed minimally elevated creatinine trends with rapid normalization. Partial prolonged and Both demonstrated higher creatinine trends with delayed normalization. Mean creatinine values were significantly different between the three types of asphyxial injuries within 13-24h of life at the time when creatinine values peaked (p=0.01). Serial newborn serum creatinine levels taken within the first 96h of life can provide objective data of timing and duration of perinatal asphyxia.

Is There Still a Place for Forceps Delivery in Modern Obstetrics?

Nowadays, we are witnessing a decrease of vaginal instrumental deliveries and continuous increase of caesarean section rate. However, proper identification of possibility of execution, indications for instrumental delivery and their skilful use may improve the broadly understood maternal and neonatal outcomes. The aim of this study is to present prevalence, risk factors, indications and outcomes of forceps deliveries among the patients at Department of Perinatology, Lodz. A retrospective study was conducted at the Department of Perinatology, Medical University of Lodz. The study included forceps deliveries carried out between January 2019 and December 2022. Total number of 147 cases were analysed in terms of indications for forceps delivery and maternal and neonatal outcomes such as vaginal - or cervical - laceration, postpartum haemorrhage, perineal tear, newborn injuries, Apgar score, umbilical cord blood gas analysis, NICU admission and cranial ultrasound scans. The prevalence of forceps delivery was 2.2%. The most common indication for forceps delivery was foetal distress (81.6%). Among mothers, the most frequent complication was vaginal laceration (40.1%). Third-and fourth-degree perineal tears were not noted. Regarding neonatal outcomes, Apgar score ≥ 8 after 1st and 5th minute of life received accordingly 91.2% and 98% of newborns. Only 8.8% experienced severe birth injuries (subperiosteal haematoma, clavicle fracture). Although foetal distress is the most common indication for forceps delivery, the vast majority of newborns were born in good condition and did not require admission to NICU. Taking into consideration high efficacy and low risk of neonatal and maternal complications, forceps should remain in modern obstetrics.

Prediction of Hypotension During Neuraxial Anesthesia in Patients with Pregnancy-Induced Hypertension Through Subclavian Vein Collapsibility Index

Objective: To explore and evaluate the predictive value of subclavian vein collapsibility index (SCV-CI) on hypotension during neuraxial anesthesia in patients with pregnancy-induced hypertension (PIH). Methods: Pregnant women with PIH who underwent elective cesarean section in our hospital from January to July 2021 were selected as the research subjects. Patients who experienced hypotension during anesthesia were included into the hypotension group, whereas patients who had a normal blood pressure during anesthesia were included in the normotensive group. The SCV-CI was then calculated for three respiratory cycles, the average value was taken as the base value, and the patient was monitored for another 20 minutes. The blood pressure, heart rate, blood oxygen saturation, and SCV-CI of the patients were measured, and the incidence of maternal nausea and vomiting and cord blood gas were recorded. Then, a correlation analysis was conducted on the relationship between subclavian vein collapsibility index and hypotension. A receiver operating characteristic curve was drawn to seek the threshold value of subclavian vein collapsibility index for post-anesthesia hypotension. Results: There was no significant difference in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) between the two groups before anesthesia (P &gt; 0.05). After anesthesia, the above indexes (SBP, 103.25 ± 12.48 mmHg; DBP, 58.94 ± 7.46 mmHg; and HR, 52.96 ± 6.48 beats/min) were significantly lower than those of the normal blood pressure group, and the difference was statistically significant (P &lt; 0.05). In comparison, the SCV-CI in the hypotension group was 35.82 ± 4.93% greater than that in the normal blood pressure group (23.85 ± 5.27%), and the incidence of nausea and vomiting in the hypotension group (40.0%) was significantly higher than that in the normotensive group (10.53%), and the difference was statistically significant (P &lt; 0.05). The area under the curve of SCV-CI prediction against hypotension in patients with PIH under neuraxial anesthesia was 0.825 (95% CI: 0.762–0.893, P &lt; 0.001), the cut-off value was 25.68%, the predictive sensitivity was 92.68%, and the specificity was 81.24%. Conclusion: SCV-CI has a good predictive value for the occurrence of hypotension in patients with PIH during neuraxial anesthesia.

Association of Umbilical Cord Blood Gas Values With Mortality and Severe Neurologic Injury in Preterm Neonates &lt;29 Weeks’ Gestation: A National Cohort Study

(Am J Obstet Gynecol. 2022;227:85.e1–10) The acid-base status of a neonate at the time of birth is determined through analysis of umbilical cord blood gas values. Deranged umbilical cord arterial (UA) and umbilical cord venous (UV) blood gas values can be linked to poor neonatal outcomes. Previous studies have found an association between a UA or UV pH value of &lt;7.0 and neonatal mortality. However, the relationship between umbilical cord blood gas values and adverse outcomes, specifically in preterm neonates born before 29 weeks gestation, is not clear. This study aimed to explore the association between umbilical cord blood gas values with neonatal mortality and severe neurological injury (SNI) in infants born before 29 weeks gestation.

Mode of delivery and neonatal outcomes with early preterm severe preeclampsia: does fetal growth restriction matter?

Objective Severe preeclampsia diagnosed at or prior to 34 weeks is an indication for preterm delivery. Many patients with severe preeclampsia develop fetal growth restriction as a result of the placental dysfunction associated with both conditions. The ideal mode of delivery in cases of preterm severe preeclampsia with fetal growth restriction remains controversial, with providers often proceeding directly to cesarean delivery rather than attempting a trial of labor due to theoretic concerns about the harms of labor in the face of placental dysfunction. There are limited data supporting this approach. This study evaluates whether the presence of fetal growth restriction affects the ultimate mode of delivery or neonatal outcomes among pregnancies with severe preeclampsia undergoing induction of labor at or before 34 weeks. Methods This was a retrospective cohort study of singletons with severe preeclampsia undergoing induction of labor ≤ 34 weeks at a single center between January 2015 and April 2022. The primary predictor was fetal growth restriction, defined as estimated fetal weight < 10th percentile for gestational age on ultrasound. Mode of delivery and neonatal outcomes were compared between those with and without fetal growth restriction using Fisher’s exact and Kruskal-Wallis tests, and multivariate logistic regression was used to obtain adjusted odds ratios. Results 159 patients were included (N = 117 without fetal growth restriction, N = 42 with fetal growth restriction). There was no difference in vaginal delivery between the groups (70% vs 67%, p = .70). While those with fetal growth restriction had a higher incidence of respiratory distress syndrome and longer neonatal hospital stay, these differences were not statistically significant after adjusting for gestational age at delivery. There were no significant differences in other neonatal outcomes, including Apgar score, cord blood gases, intraventricular hemorrhage, necrotizing enterocolitis, neonatal sepsis, and neonatal demise. Conclusion For pregnancies complicated by severe preeclampsia that require delivery ≤ 34 weeks, the likelihood of successful vaginal delivery following induction of labor does not differ based on presence of fetal growth restriction. Furthermore, fetal growth restriction is not an independent risk factor for adverse neonatal outcomes in this population. Induction of labor should be considered a reasonable approach and should be routinely offered to patients with concurrent preterm severe preeclampsia and fetal growth restriction.

Fetal oxygenation in the last weeks of pregnancy evaluated through the umbilical cord blood gas analysis.

Embryo and fetus grow and mature over the first trimester of pregnancy in a dynamic hypoxic environment, where placenta development assures an increased oxygen availability. However, it is unclear whether and how oxygenation changes in the later trimesters and, more specifically, in the last weeks of pregnancy. Observational study that evaluated the gas analysis of the umbilical cord blood collected from a cohort of healthy newborns with gestational age ≥37 weeks. Umbilical venous and arterial oxygen levels as well as fetal oxygen extraction were calculated to establish whether oxygenation level changes over the last weeks of pregnancy. In addition, fetal lactate, and carbon dioxide production were analyzed to establish whether oxygen oscillations may induce metabolic effects in utero. This study demonstrates a progressive increase in fetal oxygenation levels from the 37th to the 41st weeks of gestation (mean venous PaO2 approximately from 20 to 25 mmHg; p < 0.001). This increase is largely attributable to growing umbilical venous PaO2, regardless of delivery modalities. In neonates born by vaginal delivery, the increased oxygen availability is associated with a modest increase in oxygen extraction, while in neonates born by cesarean section, it is associated with reduced lactate production. Independently from the type of delivery, carbon dioxide production moderately increased. These findings suggest a progressive shift from a prevalent anaerobic metabolism (Warburg effect) towards a growing aerobic metabolism. This study confirms that fetuses grow in a hypoxic environment that becomes progressively less hypoxic in the last weeks of gestation. The increased oxygen availability seems to favor aerobic metabolic shift during the last weeks of intrauterine life; we hypothesize that this environmental change may have implications for fetal maturation during intrauterine life.

Umbilical cord blood acid-base analysis at birth and long-term neurodevelopmental outcomes in children: a systematic review and meta-analysis.

Umbilical cord blood acid-base sampling is routinely performed at many hospitals. Recent studies have questioned this practice and the association of acidosis with cerebral palsy. To investigate the associations between the results of umbilical cord blood acid-base analysis at birth and long-term neurodevelopmental outcomes and mortality in children. We searched six databases using the search strategy: umbilical cord AND outcomes. Randomised controlled trials, cohorts and case-control studies from high-income countries that investigated the association between umbilical cord blood analysis and neurodevelopmental outcomes and mortality from 1 year after birth in children born at term. We critically assessed the included studies, extracted data and conducted meta-analyses comparing adverse outcomes between children with and without acidosis, and the mean proportions of adverse outcomes. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach. We have very low confidence in the following findings: acidosis was associated with higher cognitive development scores compared with non-acidosis (mean difference 5.18, 95% CI 0.84-9.52; n = two studies). Children with acidosis also showed a tendency towards higher risk of death (relative risk [RR] 5.72, 95% CI 0.90-36.27; n = four studies) and CP (RR 3.40, 95% CI 0.86-13.39; n = four studies), although this was not statistically significant. The proportion of children with CP was 2.39/1000 across the studies, assessed as high certainty evidence. Due to low certainty of evidence, the associations between umbilical cord blood gas analysis at delivery and long-term neurodevelopmental outcomes in children remains unclear.

Implementation of universal umbilical cord pH analysis in Denmark. A national register-based study.

Umbilical cord blood gas analysis provides information about intrapartum hypoxia and is considered an important measure of quality in maternity care. Universal measurement of umbilical cord pH (UC-pH), as part of umbilical cord blood gas analysis, has been recommended in Denmark since 2009. The recommendation is that UC-pH is measured from the umbilical cord artery (pHUA ) and vein (pHUV ). The aim of this study was to evaluate the national implementation of universal measurement of UC-pH. The study consisted of two parts. First, an evaluation of the implementation, that is, the proportion of births with measured UC-pH since the recommendation was introduced. Second, an evaluation of the cases in which UC-pH was missing. This analysis only involved births with gestational age ≥35 + 0 weeks. In the period 2009 to 2018 there were 560 889 singleton, live births with registered gestational age in Denmark. The proportion of births with measured pHUA and pHUV increased from 12.4% in 2009 to 82.8% in 2015 and then declined to 76.9% in 2018 (p < 0.001). When comparing the group with missing pH from one or both vessels to the group with both pHUA and pHUV we found lower occurrence of pregnancy and births complications in the first group, body mass index ≥35 (unadjusted RR: 0.89, 95% CI: 0.85-0.93), pregnancy induced medical conditions (RR: 0.86, 95% CI: 0.84-0.89), fetal distress during birth (RR: 0.77, 95% CI: 0.76-0.79), emergency cesarean section (RR: 0.80, 95% CI: 0.78-0.83) and serious births events (RR: 0.80, 95% CI: 0.74-0.86). In contrast, the occurrence of placental insufficiency (RR: 1.07, 95% CI: 1.03-1.11), small for gestational age (RR: 1.36, 95% CI: 1.30-1.43, for <2.3th percentile), hypothermia treatment (RR: 1.60, 95% CI: 1.21-2.14) and neonatal death (RR: 1.96, 95% CI: 1.40-2.74) were higher in the group without measured pHUA and pHUV . The use of UC-pH measurement has increased markedly in Denmark since universal measurement was recommended in 2009. Missing UC-pH from one or both vessels was associated with less complicated pregnancies and with small for gestational age, hypothermia treatment and neonatal death.

The effect of cord clamping time on cord blood gas in term newborn babies delivered by cesarean section

Objective: Umbilical cord clamping time is a situation that should be planned before delivery. It is recommended that the umbilical cord be clamped for at least 30–60 seconds after birth in healthy preterm and term newborns. There are few studies investigating the effect of umbilical cord clamping time on cord blood gas. If the umbilical cord is clamped before 30 seconds after birth, it is considered early clamping, and if it is clamped after 30 seconds, it is considered late clamping. In this study, we aimed to compare the early or late clamping time of the umbilical cord with the acid-base parameters and lactate values of babies. Methods: A total of 217 term newborn infants who were delivered by cesarean section between December 2020 and December 2021 in our hospital, whose umbilical cord clamping times were recorded and who had cord blood samples, were included in our study retrospectively. pH, pCO2, pO2, HCO3, BE, lactate, Hb and bilirubin values in cord blood gas samples were compared between the two groups. Results: Two hundred seventeen term newborn babies were included in the study. Cord clamping time of infants was delayed in 125 (57.6%) and early in 92 (42.4%) infants. The mean pH in cord blood gas was 7.37±0.07 (7.16–7.57), pCO2 was 39.73 ±8.97 (20.3–65.4) mmHg, pO2 was 53.42±41.95 (14.8–198) mmHg, BE was -2.18±2.90 (-11.9–13.6) mmol/L, lactate was 2.12±0.88 (0.50–5.90) mmol/L, Hb was 14.57± 2.54 (10–23.7) g/dl, and bilirubin was 1.71±1.33 (0–3.7) mg/dl. Conclusion: There was no significant relationship between early and late clamping of the umbilical cord and acid-base parameters, and hemoglobin values in cord blood gas in term newborn babies delivered by cesarean section.

Trajectory of serum bilirubin in offspring of women with gestational diabetes mellitus

AimsTo investigate the trajectory of bilirubin from birth to the first 48 h of life in neonates of women with gestational diabetes. MethodsIn a cohort of 69 neonates of women with gestational diabetes, delivered at Policlinic Abano, Abano Terme, Italy, from October 2021 to May 2022, we conducted a case–control study (1:2 ratio) on total serum bilirubin (TSB) trajectory over the first 48 h after birth. An ancillary analysis was conducted on arterial cord blood gas analysis at birth and on concurrent hemoglobin, hematocrit, lactate, glycemia, and bilirubin levels. ResultsThe neonates of women with gestational diabetes showed a significantly higher mean percent variation of TSB from birth to the first 48 h of life (p = 0.01), a finding supported by a higher, although not significant, TSB levels at 48 h of life in comparison to controls (8.05 ± 4.8 vs 8.05 ± 4 mg%, p = 0.082), and by a significantly lower cord TSB levels (2.3 ± 0.9 vs 2.6 ± 0.9 mg%, p = 0.010). ConclusionsThe findings suggest that future primary studies on hyperbilirubinemia risk in neonates of women with gestational diabetes should consider the trajectory of TSB beyond the first 48 h, adjusting for a more complete set of pre-pregnancy and gestational prognostic risk factors.

Cerebral Tissue Oxygen Saturation Measurements in Perinatal Asphyxia Cases Treated with Therapeutic Hypothermia.

Cerebral tissue oxygen saturation (CrSO2) measured with near-infrared spectroscopy (NIRS) technology has recently become the subject of several research studies. The aim of this study was to investigate the diagnostic value of CrSO2 measurements in perinatal asphyxia (PA) cases. The study included a patient group of 42 PA cases, who were to be applied with therapeutic hypothermia (TH), and a control group of 42 healthy term newborns. PA cases were determined as moderate or severe encephalopathy (Sarnat score stage II or III) in clinical evaluation. In both groups, left (CrSO2L) and right (CrSO2R) NIRS measurements were taken for 10 minutes on the scalp. The arithmetic mean value of measurements was calculated and compared. The mean measurements were CrSO2R 67.38 ± 9.39 and CrSO2L 66.73 ± 7.76 in the patient group, and CrSO2R 80.28 ± 8.04 and CrSO2L 79.14 ± 8.49 in the control group. The mean CrSO2R and CrSO2L measurements of the patient group were statistically significantly lower than those of the control group (p < 0.001). In the Pearson correlation analysis, a significant correlation was determined in the patient group between cord blood gas pH and CrSO2R (r: 0.539, p < 0.001) and CrSO2L (r: 0.54, p < 0.001). For a cutoff value of CrSO2L ≤ 72%, the positive predictive value was 80 and the negative predictive value was 84.6. For a cutoff value of CrSO2R ≤ 74%, the positive predictive value was 79.5 and the negative predictive value was 82.5. Low CrSO2 measurements obtained with the NIRS method in PA cases to be applied with TH together with cord blood gas parameters can be considered a helpful parameter in diagnosis.

Incidence of bradycardia during noradrenaline or phenylephrine bolus treatment of postspinal hypotension in cesarean delivery: A randomized double-blinded controlled trial.

The treatment of choice for spinal anesthesia-induced hypotension during cesarean section is phenylephrine. As this vasopressor can cause reflex bradycardia, noradrenaline is a suggested alternative. This randomized double-blinded controlled trial included 76 parturients undergoing elective cesarean delivery under spinal anesthesia. Women received noradrenaline in bolus doses of 5mcg or phenylephrine in bolus doses of 100 mcg. These drugs were used intermittently and therapeutically to maintain systolic blood pressure ≥ 90% of its baseline value. The primary study outcome was bradycardia incidence (<60 bpm) with intermittent bolus administration of these drugs. Secondary outcomes included extreme bradycardia (<40 bpm), number of bradycardia episodes, hypertension (systolic blood pressure > 120% of baseline value), and hypotension (systolic blood pressure < 90% of baseline value and requiring vasopressor use). Neonatal outcomes per the Apgar scale and umbilical cord blood gas analysis were also compared. The incidence of bradycardia in both groups (51.4% and 70.3%, respectively; p=0.16) were not significantly different. No neonates had umbilical vein or artery pH values below 7.20. The noradrenaline group required more boluses than phenylephrine group (8 vs. 5; p=0.01). There was no significant intergroup difference in any of the other secondary outcomes. When administered in intermittent bolus doses for the treatment of postspinal hypotension in elective cesarean delivery, noradrenaline, and phenylephrine have a similar incidence of bradycardia. When treating hypotension related to spinal anesthesia in obstetric cases, strong vasopressors are commonly administered, thought these can also have side effects. This trial assessed bradycardia after bolus administration of noradrenaline or phenylephrine, and found no difference in risk for clinically meaningful bradycardia.

Adverse neonatal outcome and veno-arterial differences in umbilical cord blood pH (ΔpH) at birth: a population-based study of 108,629 newborns

BackgroundUmbilical cord blood gases are routinely used by midwives and obstetricians for quality assurance of birth management and in clinical research. They can form the basis for solving medicolegal issues in the identification of severe intrapartum hypoxia at birth. However, the scientific value of veno-arterial differences in cord blood pH, also known as ΔpH, is largely unknown. By tradition, the Apgar score is frequently used to predict perinatal morbidity and mortality, however significant inter-observer and regional variations decrease its reliability and there is a need to identify more accurate markers of perinatal asphyxia. The aim of our study was to investigate the association of small and large veno-arterial differences in umbilical cord pH, ΔpH, with adverse neonatal outcome.MethodsThis retrospective, population-based study collected obstetric and neonatal data from women giving birth in nine maternity units from Southern Sweden from 1995 to 2015. Data was extracted from the Perinatal South Revision Register, a quality regional health database. Newborns at ≥37 gestational weeks with a complete and validated set of umbilical cord blood samples from both cord artery and vein were included. Outcome measures included: ΔpH percentiles, ‘Small ΔpH’ (10th percentile), ‘Large ΔpH’ (90th percentile), Apgar score (0–6), need for continuous positive airway pressure (CPAP) and admission to neonatal intensive care unit (NICU). Relative risks (RR) were calculated with modified Poisson regression model.ResultsThe study population comprised of 108,629 newborns with complete and validated data. Mean and median ΔpH was 0.08 ± 0.05. Analyses of RR showed that ‘Large ΔpH’ was associated with a decreased RR of adverse perinatal outcome with increasing UApH (at UApH ≥7.20: RR for low Apgar 0.29, P = 0.01; CPAP 0.55, P = 0.02; NICU admission 0.81, P = 0.01). ‘Small ΔpH’ was associated with an increased RR for low Apgar score and NICU admission only at higher UApH values (at UApH 7.15–7.199: RR for low Apgar 1.96, P = 0.01; at UApH ≥7.20: RR for low Apgar 1.65, P = 0.00, RR for NICU admission 1.13, P = 0.01).ConclusionLarge differences between cord venous and arterial pH (ΔpH) at birth were associated with a lower risk for perinatal morbidity including low 5-minute Apgar Score, the need for continuous positive airway pressure and NICU admission when UApH was above 7.15. Clinically, ΔpH may be a useful tool in the assessment of the newborn’s metabolic condition at birth. Our findings may stem from the ability of the placenta to adequately replenish acid-base balance in fetal blood. ‘Large ΔpH’ may therefore be a marker of effective gas exchange in the placenta during birth.

Determination of maternal serum pro-inflammatory cytokine changes in intrauterine growth restriction.

To evaluate maternal serum inflammatory marker changes in intrauterine growth restriction (IUGR) pregnancies. 50 healthy pregnant women and 50 patients diagnosed with IUGR were enrolled. Maternal serum high sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-10 levels were measured before delivery and neonatal outcomes were evaluated. Birth weight, Apgar scores, and cord blood gas pH were lower in the IUGR group (p<0.001, p<0.001, p<0.001 and p=0.006, respectively). While the levels of ESR, hsCRP, IL-6, and TNF-α were higher, the IL-10 level was found to be lower in the IUGR group (p<0.001, p=0.033, p<0.001, p=0.004 and p<0.001, respectively). As ESR, hsCRP, and IL-6 levels increased, birth weight, Apgar scores, and cord blood gas pH decreased (p<0.001, p<0.001, p<0.001, p<0.001, p=0.02, p=0.002, p=0.001, p=0.03, p<0.001, p<0.001, p<0.001 and p=0.02, respectively). As TNF-α level increased, only birth weight and Apgar score at the 1st minute decreased (p=0.006 and p=0.048, respectively). As IL-10 level decreased, birth weight, Apgar scores, and cord blood gas pH decreased (p<0.001 for all). IL-6 (>3.2 pg/ml) had a sensitivity of 100%, specificity of 100%, PPV of 100% and NPV of 100%. While birth weight, Apgar score and cord blood pH decreased in IUGR cases, ESR, hsCRP, IL-6 and TNF-α levels increased. Combined measurement of these markers can be used for the diagnosis of IUGR.

Arterial blood gases in newborn infants: Early extraction without prior clamping versus extraction after delayed clamping

ObjectivesTo compare the postpartum arterial blood gas parameters recorded early before cord clamping and after delayed cord clamping (DCC). To explore adverse effects and complications of the cord blood gas collection technique without clamping. DesignRandomised controlled trial. SettingBirthing room of La Ribera University Hospital (Valencia, Spain). Participants122 full-term infants born between February 2020 and January 2021. Two groups were established: the experimental group (early sampling prior to clamping and sampling again after DCC) and the non-experimental group (sampling only after DCC). Measurements and findingsThe comparison of arterial blood gas parameters was made using the Student t-test, while the Fisher's exact test was used to compare the proportion of the adverse effects recorded. The pH and base excess values in the experimental group were significantly greater when the sampling was performed without prior clamping. No statistically significant differences were observed in relation to pCO2 or the appearance of adverse effects between the two groups. No complications were recorded. Key conclusions and implications for practiceThe pH and base excess values were higher when the arterial blood gas measurements were made prior to performing the umbilical cord clamping than when the sampling was performed after the DCC. Arterial blood gas sampling without prior clamping was found to be safe, since no complications or increased adverse effects were observed. The use of this technique is therefore advised in normal births of full-term infants.