Umbilical cord pH and base excess values in relation to adverse outcome events for infants delivering at term

Umbilical Cord pH Levels and Neonatal Morbidity and Mortality

Importance

Umbilical cord pH (UC-pH) level is an important objective indicator of intrapartum fetal hypoxia and is used to predict neonatal morbidity and mortality. A UC-pH value of less than 7.00 is often defined as a threshold for severe acidosis, but existing evidence is divergent and largely based on UC-pH measurements from selected populations; consequently, the results are challenging to interpret.

Objective

To investigate the association between UC-pH levels and the risk of adverse neonatal outcomes in a national setting with universal UC-pH measurement.

Design, Setting, and Participants

This national, population-based cohort study included all liveborn, singleton, full-term infants without malformations born in Denmark from January 1, 2012, to December 31, 2018. Data were analyzed from January 1, 2023, to March 1, 2024.

Exposure

Umbilical cord pH level categorized as less than 7.00, 7.00 to 7.09, 7.10 to 7.19 and 7.20 to 7.50 (reference group).

Main Outcomes and Measures

The primary outcome was a composite of severe adverse neonatal outcomes: neonatal death, therapeutic hypothermia, mechanical ventilation, treatment with inhaled nitric oxide, or seizures. Secondary outcomes were individual components of the primary outcome, Apgar score, respiratory outcomes, and hypoglycemia. Data are presented as adjusted risk ratios (ARRs) with 95% CIs.

Results

Among the 340 431 infants included, mean (SD) gestational age was 39.9 (1.6) weeks; mean (SD) birth weight was 3561 (480) g; and 51.3% were male. Umbilical cord pH of less than 7.20 was observed more often among infants with a gestational age of 40 or 41 weeks (31.6%-33.6% compared with 18.2%-20.2% at a gestational age of 39 weeks) and among male infants (53.9%-55.4% vs 44.6%-46.1% among female infants). Compared with the pH reference group (576 of 253 540 [0.2%]), the risk for the primary outcome was increased for the groups with UC-pH levels of less than 7.00 (171 of 1743 [9.8%]), 7.00 to 7.09 (101 of 11 904 [0.8%]), and 7.10 to 7.19 (259 of 73 244 [0.4%]). Comparable patterns were observed for the individual outcomes, except for neonatal death, which was only increased in the group with UC-pH levels of less than 7.10. The risk of treatment with continuous positive airway pressure was increased when UC-pH levels were less than 7.20, and the risk of hypoglycemia was 21.5% if UC-pH levels were less than 7.10.

Conclusions and Relevance

In this cohort study of 340 431 newborn infants, results support and extend previous studies indicating a higher risk of adverse outcomes even at UC-pH levels above 7.00. The threshold for more intensive observation and treatment may be reconsidered.

Epidural analgesia and neonatal short-term outcomes during routine childbirth: a 10-year retrospective analysis from the national birth registry of Austria

BACKGROUND

Epidural analgesia (EA) is well-accepted for pain relief during labor. Still, the impact on neonatal short-term outcome is under continuous debate. This study assessed the outcome of neonates in deliveries with and without EA in a nationwide cohort.

METHODS

We analyzed the National Birth Registry of Austria between 2008 and 2017 of primiparous women with vaginal birth of singleton pregnancies. Neonatal short-term morbidity was assessed by arterial cord pH and base excess (BE). Secondary outcomes were admission to a neonatological intensive care unit, APGAR scores, and perinatal mortality. Propensity score-adjusted regression models were used to investigate the association of EA with short-term neonatal outcome.

RESULTS

Of 247,536 included deliveries, 52 153 received EA (21%). Differences in pH (7.24 vs. 7.25; 97.5% CI -0.0066 to -0.0047) and BE (-5.89±3.2 vs. -6.15±3.2 mmol/L; 97.5% CI 0.32 to 0.40) with EA could be shown. APGAR score at five minutes <7 was more frequent with EA (OR 1.45; 95% CI: 1.29 to 1.63). Admission to a neonatological intensive care unit occurred more often with EA (4.7% vs. 3.4%) with an OR for EA of 1.2 (95% CI: 1.14 to 1.26). EA was not associated with perinatal mortality (OR 1.33; 95% CI: 0.79 to 2.25).

CONCLUSIONS

EA showed no clinically relevant association with neonatal short-term outcome. Higher rates of NICU admission and APGAR score after five minutes <7 were observed with EA. The overall use of EA in Austria is low, and an investigation of causes may be indicated.

Trends in Apgar scores and umbilical artery pH: a population-based cohort study on 10,696,831 live births in Germany, 2008-2022

Low Apgar scores and low umbilical arterial (UA) blood pH are considered indicators of adverse perinatal events. This study investigated trends of these perinatal health indicators in Germany. Perinatal data on 10,696,831 in-hospital live births from 2008 to 2022 were obtained from quality assurance institutes. Joinpoint regression analysis was used to quantify trends of low Apgar score and UA pH. Additional analyses stratified by mode of delivery were performed on term singletons with cephalic presentation. Robustness against unmeasured confounding was analyzed using the E-value sensitivity analysis. The overall rates of 5-min Apgar scores < 7 and UA pH < 7.10 in liveborn infants were 1.17% and 1.98%, respectively. For low Apgar scores, joinpoint analysis revealed an increase from 2008 to 2011 (annual percent change (APC) 5.19; 95% CI 3.66-9.00) followed by a slower increase from 2011 to 2019 (APC 2.56; 95% CI 2.00-3.03) and a stabilization from 2019 onwards (APC - 0.64; 95% CI - 3.60 to 0.62). The rate of UA blood pH < 7.10 increased significantly between 2011 and 2017 (APC 5.90; 95% CI 5.15-7.42). For term singletons in cephalic presentation, the risk amplification of low Apgar scores was highest after instrumental delivery (risk ratio 1.623, 95% CI 1.509-1.745), whereas those born spontaneous had the highest increase in pH < 7.10 (risk ratio 1.648, 95% CI 1.615-1.682).          Conclusion: Rates of low 5-min Apgar scores and UA pH in liveborn infants increased from 2008 to 2022 in Germany. What is Known: • Low Apgar scores at 5 min after birth and umbilical arterial blood pH are associated with adverse perinatal outcomes. • Prospective collection of Apgar scores and arterial blood pH data allows for nationwide quality assurance. What is New: • The rates of liveborn infants with 5-min Apgar scores < 7 rose from 0.97 to 1.30% and that of umbilical arterial blood pH < 7.10 from 1.55 to 2.30% between 2008-2010 and 2020-2022. • In spontaneously born term singletons in cephalic presentation, the rate of metabolic acidosis with pH < 7.10 and BE < -5 mmol/L in umbilical arterial blood roughly doubled between the periods 2008-2010 and 2020-2022.

Nonreassuring fetal status during labor and offspring's childhood neurodevelopment at 3 years of age: The Japan Environment and Children's Study

OBJECTIVE

Although prior attempts have failed to identify the beneficial effects of intensive fetal monitoring on cerebral palsy, the association between nonreassuring fetal status (NRFS) during labor and the incidence of long-term neurodevelopmental delays in offspring remains unclear. This study aimed to evaluate this association using a nationwide birth cohort.

METHODS

Data from 72 869 women with singleton deliveries at and after 37 weeks of gestation from the Japan Environment and Children's Study (2011-2014) were analyzed. Multivariable logistic regression models were used to analyze the odds ratios (ORs) for neurodevelopmental delays using the Ages & Stages Questionnaire (Third Edition) in offspring aged 3 years.

RESULTS

The adjusted ORs for personal-social problems were 1.52 (95% confidence interval [CI], 1.06-2.16) for offspring delivered vaginally by nulliparous mothers and 1.51 (95% CI, 1.05-2.18) (for males, 1.70 [95% CI, 1.15-2.50]) for those delivered via cesarean section. No significant changes in adjusted ORs for neurodevelopmental delays were observed among participants without neonatal Apgar scores (ASs) <7 and without umbilical arterial pH (UmA-pH) <7.20.

CONCLUSION

NRFS during labor was associated with an increased incidence of personal-social problems in offspring aged 3 years. However, this association was not confirmed after excluding participants with neonatal ASs <7 and UmA-pH <7.20. The association between NRFS and offspring's neurodevelopmental delays might vary based on delivery settings, offspring sex, and short-term neonatal outcomes.

Machine learning on cardiotocography data to classify fetal outcomes: A scoping review

INTRODUCTION

Uterine contractions during labour constrict maternal blood flow and oxygen delivery to the developing baby, causing transient hypoxia. While most babies are physiologically adapted to withstand such intrapartum hypoxia, those exposed to severe hypoxia or with poor physiological reserves may experience neurological injury or death during labour. Cardiotocography (CTG) monitoring was developed to identify babies at risk of hypoxia by detecting changes in fetal heart rate (FHR) patterns. CTG monitoring is in widespread use in intrapartum care for the detection of fetal hypoxia, but the clinical utility is limited by a relatively poor positive predictive value (PPV) of an abnormal CTG and significant inter and intra observer variability in CTG interpretation. Clinical risk and human factors may impact the quality of CTG interpretation. Misclassification of CTG traces may lead to both under-treatment (with the risk of fetal injury or death) or over-treatment (which may include unnecessary operative interventions that put both mother and baby at risk of complications). Machine learning (ML) has been applied to this problem since early 2000 and has shown potential to predict fetal hypoxia more accurately than visual interpretation of CTG alone. To consider how these tools might be translated for clinical practice, we conducted a review of ML techniques already applied to CTG classification and identified research gaps requiring investigation in order to progress towards clinical implementation.

MATERIALS AND METHOD

We used identified keywords to search databases for relevant publications on PubMed, EMBASE and IEEE Xplore. We used Preferred Reporting Items for Systematic Review and Meta-Analysis for Scoping Reviews (PRISMA-ScR). Title, abstract and full text were screened according to the inclusion criteria.

RESULTS

We included 36 studies that used signal processing and ML techniques to classify CTG. Most studies used an open-access CTG database and predominantly used fetal metabolic acidosis as the benchmark for hypoxia with varying pH levels. Various methods were used to process and extract CTG signals and several ML algorithms were used to classify CTG. We identified significant concerns over the practicality of using varying pH levels as the CTG classification benchmark. Furthermore, studies needed to be more generalised as most used the same database with a low number of subjects for an ML study.

CONCLUSION

ML studies demonstrate potential in predicting fetal hypoxia from CTG. However, more diverse datasets, standardisation of hypoxia benchmarks and enhancement of algorithms and features are needed for future clinical implementation.

Impact of an e-learning training for interpreting intrapartum fetal heart rate monitoring to avoid perinatal asphyxia: A before-after multicenter observational study

INTRODUCTION

Perinatal asphyxia, a condition that results from compromised placental or pulmonary gas exchange during the birth process, is rare but can lead to serious neonatal and long-term consequences. The visual analysis of cardiotocography (CTG) is designed to avoid perinatal asphyxia, but its interpretation can be difficult. Our aim was to test the impact of an e-learning training program for interpreting CTG on the rate of avoidable perinatal asphyxia at term.

METHOD

We conducted a retrospective multicenter before-after study comparing two periods, before and after the implementation of e-learning training program from July 1, 2016 to December 31, 2016, in CTG interpretation for midwives and obstetricians in five maternity hospitals in the Paris area, France. The training involved theoretical aspects such as fetal physiology and heart rhythm abnormalities, followed by practical exercises using real case studies to enhance skills in interpreting CTG. We included all term births that occurred between the "before" period (July 1 to December 31, 2014) and the "after period (January 1 to June 30, 2017). We excluded multiple pregnancies, antenatal detection of congenital abnormalities, breech births and all scheduled caesarean sections. Perinatal asphyxia cases were analyzed by a pair of experts consisting of midwives and obstetricians, and avoidability of perinatal asphyxia was estimated. The main criterion was the prevalence of avoidable perinatal asphyxia.

RESULTS

The e-learning program was performed by 83 % of the obstetrician-gynecologists and 65 % of the midwives working in the delivery rooms of the five centers. The prevalence of perinatal asphyxia was 0.45 % (29/7902 births) before the training and 0.54 % (35/7722) after. The rate of perinatal asphyxia rated as avoidable was 0.30 % of live births before the training and 0.28 % after (p = 0.870). The main causes of perinatal asphyxia deemed avoidable were delay in reactions to severe CTG anomalies and errors in the analysis and interpretation of the CTG. These causes did not differ between the two periods.

CONCLUSION

One session of e-learning training to analyze CTG was not associated with a reduction in avoidable perinatal asphyxia. Other types of e-learning, repeated and implemented over a longer period should be evaluated.

Umbilical cord blood gases sampling in low-risk vaginal deliveries as a predictor of adverse neonatal outcome

INTRODUCTION

There is no clear correlation between abnormal umbilical cord blood gas studies (UCGS) and adverse neonatal outcome in low-risk deliveries. We investigated the need for its routine use in low-risk deliveries.

METHODS

We retrospectively compared maternal, neonatal, and obstetrical characteristics among low-risk deliveries (2014-2022) between "normal" and "abnormal" pH groups: A:normal pH ≥ 7.15; abnormal pH < 7.15; B: normal pH ≥ 7.15 and base excess (BE) > - 12 mmol/L; abnormal pH < 7.15 and BE ≤ We retrospectively compared 12 mmol/L; C: normal pH ≥ 7.1; abnormal pH < 7.1; D: normal pH > 7.1 and BE > - 12 mmol/L; abnormal pH < 7.1 and BE ≤ - 12 mmol/L.

RESULTS

Of 14,338 deliveries, the rates of UCGS were: A-0.3% (n = 43); B-0.07% (n = 10); C-0.11% (n = 17); D-0.03% (n = 4). The primary outcome, composite adverse neonatal outcome (CANO) occurred in 178 neonates with normal UCGS (1.2%) and in only one case with UCGS (2.6%). The sensitivity and specificity of UCGS as a predictor of CANO were high (99.7-99.9%) and low (0.56-0.59%), respectively.

CONCLUSION

UCGS were an uncommon finding in low-risk deliveries and its association with CANO was not clinically relevant. Consequently, its routine use should be considered.

Prevention of fetal brain injury in category II tracings

INTRODUCTION

With category II fetal heart rate tracings, the preferred timing of interventions to prevent fetal hypoxic brain damage while limiting operative interventions remains unclear. We aimed to estimate fetal extracellular base deficit (BDecf ) during labor with category II tracings to quantify the timing of potential interventions to prevent severe fetal metabolic acidemia.

MATERIAL AND METHODS

A longitudinal study was conducted using the database of the Recurrence Prevention Committee, Japan Obstetric Compensation System for Cerebral Palsy, including infants with severe cerebral palsy born at ≥34 weeks' gestation between 2009 and 2014. Cases included those presumed to have an intrapartum onset of hypoxic-ischemic insult based on the fetal heart rate pattern evolution from reassuring to an abnormal pattern during delivery, in association with category II tracings marked by recurrent decelerations and an umbilical arterial BDecf  ≥ 12 mEq/L. BDecf changes during labor were estimated based on stages of labor and the frequency/severity of fetal heart rate decelerations using the algorithm of Ross and Gala. The times from the onset of recurrent decelerations to BDecf 8 and 12 mEq/L (Decels-to-BD8, Decels-to-BD12) and to delivery were determined. Cases were divided into two groups (rapid and slow progression) based upon the rate of progression of acidosis from onset of decelerations to BDecf 12 mEq/L, determined by a finite-mixture model.

RESULTS

The median Decels-to-BD8 (28 vs. 144 min, p < 0.01) and Decels-to-BD12 (46 vs. 177 min, p < 0.01) times were significantly shorter in the rapid vs slow progression. In rapid progression cases, physicians' decisions to deliver the fetus occurred at ~BDecf 8 mEq/L, whereas the "decisions" did not occur until BDecf reached 12 mEq/L in slow progression cases.

CONCLUSIONS

Fetal BDecf reached 12 mEq/L within 1 h of recurrent fetal heart rate decelerations in the rapid progression group and within 3 h in the slow progression group. These findings suggest that cases with category II tracings marked by recurrent decelerations (i.e., slow progression) may benefit from operative intervention if persisting for longer than 2 h. In contrast, cases with sudden bradycardia (i.e., rapid progression) represent a challenge to prevent severe acidosis and hypoxic brain injury due to the limited time opportunity for emergent delivery.

Umbilical cord pH, blood gases, and lactate at birth: normal values, interpretation, and clinical utility

Normal birth is a eustress reaction, a beneficial hedonic stress with extremely high catecholamines that protects us from intrauterine hypoxia and assists in the rapid shift to extrauterine life. Occasionally the cellular O2 requirement becomes critical and an O2 deficit in blood (hypoxemia) may evolve to a tissue deficit (hypoxia) and finally a risk of organ damage (asphyxia). An increase in H+ concentration is reflected in a decrease in pH, which together with increased base deficit is a proxy for the level of fetal O2 deficit. Base deficit (or its negative value, base excess) was introduced to reflect the metabolic component of a low pH and to distinguish from the respiratory cause of a low pH, which is a high CO2 concentration. Base deficit is a theoretical estimate and not a measured parameter, calculated by the blood gas analyzer from values of pH, the partial pressure of CO2, and hemoglobin. Different brands of analyzers use different calculation equations, and base deficit values can thus differ by multiples. This could influence the diagnosis of metabolic acidosis, which is commonly defined as a pH <7.00 combined with a base deficit ≥12.0 mmol/L in umbilical cord arterial blood. Base deficit can be calculated as base deficit in blood (or actual base deficit) or base deficit in extracellular fluid (or standard base deficit). The extracellular fluid compartment represents the blood volume diluted with the interstitial fluid. Base deficit in extracellular fluid is advocated for fetal blood because a high partial pressure of CO2 (hypercapnia) is common in newborns without concomitant hypoxia, and hypercapnia has a strong influence on the pH value, then termed respiratory acidosis. An increase in partial pressure of CO2 causes less increase in base deficit in extracellular fluid than in base deficit in blood, thus base deficit in extracellular fluid better represents the metabolic component of acidosis. The different types of base deficit for defining metabolic acidosis in cord blood have unfortunately not been noticed by many obstetrical experts and organizations. In addition to an increase in H+ concentration, the lactate production is accelerated during hypoxia and anaerobic metabolism. There is no global consensus on definitions of normal cord blood gases and lactate, and different cutoff values for abnormality are used. At a pH <7.20, 7% to 9% of newborns are deemed academic; at <7.10, 1% to 3%; and at <7.00, 0.26% to 1.3%. From numerous studies of different eras and sizes, it can firmly be concluded that in the cord artery, the statistically defined lower pH limit (mean -2 standard deviations) is 7.10. Given that the pH for optimal enzyme activity differs between different cell types and organs, it seems difficult to establish a general biologically critical pH limit. The blood gases and lactate in cord blood change with the progression of pregnancy toward a mixed metabolic and respiratory acidemia because of increased metabolism and CO2 production in the growing fetus. Gestational age-adjusted normal reference values have accordingly been published for pH and lactate, and they associate with Apgar score slightly better than stationary cutoffs, but they are not widely used in clinical practice. On the basis of good-quality data, it is reasonable to set a cord artery lactate cutoff (mean +2 standard deviations) at 10 mmol/L at 39 to 40 weeks' gestation. For base deficit, it is not possible to establish statistically defined reference values because base deficit is calculated with different equations, and there is no consensus on which to use. Arterial cord blood represents the fetus better than venous blood, and samples from both vessels are needed to validate the arterial origin. A venoarterial pH gradient of <0.02 is commonly used to differentiate arterial from venous samples. Reference values for pH in cord venous blood have been determined, but venous blood comes from the placenta after clearance of a surplus of arterial CO2, and base deficit in venous blood then overestimates the metabolic component of fetal acidosis. The ambition to increase neonatal hemoglobin and iron depots by delaying cord clamping after birth results in falsely acidic blood gas and lactate values if the blood sampling is also delayed. Within seconds after birth, sour metabolites accumulated in peripheral tissues and organs will flood into the central circulation and further to the cord arteries when the newborn starts to breathe, move, and cry. This influence of "hidden acidosis" can be avoided by needle puncture of unclamped cord vessels and blood collection immediately after birth. Because of a continuing anaerobic glycolysis in the collected blood, it should be analyzed within 5 minutes to not result in a falsely high lactate value. If the syringe is placed in ice slurry, the time limit is 20 minutes. For pH, it is reasonable to wait no longer than 15 minutes if not in ice. Routine analyses of cord blood gases enable perinatal audits to gain the wisdom of hindsight, to maintain quality assurance at a maternity unit over years by following the rate of neonatal acidosis, to compare results between hospitals on regional or national bases, and to obtain an objective outcome measure in clinical research. Given that the intrapartum cardiotocogram is an uncertain proxy for fetal hypoxia, and there is no strong correlation between pathologic cardiotocograms and fetal acidosis, a cord artery pH may help rather than hurt a staff person subjected to a malpractice suit based on undesirable cardiotocogram patterns. Contrary to common beliefs and assumptions, up to 90% of cases of cerebral palsy do not originate from intrapartum events. Future research will elucidate whether cell injury markers with point-of-care analysis will become valuable in improving the dating of perinatal injuries and differentiating hypoxic from nonhypoxic injuries.

Low Apgar score and need for resuscitation increased the probability of receiving therapeutic hypothermia more strongly than acidosis at birth

AIM

The aim of this study was to investigate how individual markers for birth asphyxia, so-called A criteria, were associated with the probability of receiving therapeutic hypothermia.

METHODS

This population-based cohort study included 1336 live-born singleton term infants with any A criterion in the Stockholm-Gotland Region, Sweden during 2008 to 2014. The Swedish Neonatal Quality Register and National Patient Register were used for data collection. Results were presented as adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

RESULTS

There were 89 infants, 44 boys and 45 girls with mean gestational age 40.5 weeks, who received therapeutic hypothermia. Low Apgar score, aOR 12.44 (95% CI 5.99-25.86), and resuscitation, aOR 9.18 (95% CI 3.77-22.34), were strongly associated with therapeutic hypothermia. A pH <7.0 was less associated with the outcome, aOR 2.02 (95% CI 1.02-4.0). No infant who received therapeutic hypothermia fulfilled the criteria of base deficit ≥16 mmol/L only.

CONCLUSION

A low Apgar score of and/or a need for resuscitation is more relevant for identifying infants eligible for therapeutic hypothermia, compared to other A criteria. This knowledge could be used clinically to identify cases for review and avoid unnecessary monitoring of infants.

Maternal and newborn plasma oxytocin levels in response to maternal synthetic oxytocin administration during labour, birth and postpartum - a systematic review with implications for the function of the oxytocinergic system

BACKGROUND

The reproductive hormone oxytocin facilitates labour, birth and postpartum adaptations for women and newborns. Synthetic oxytocin is commonly given to induce or augment labour and to decrease postpartum bleeding.

AIM

To systematically review studies measuring plasma oxytocin levels in women and newborns following maternal administration of synthetic oxytocin during labour, birth and/or postpartum and to consider possible impacts on endogenous oxytocin and related systems.

METHODS

Systematic searches of PubMed, CINAHL, PsycInfo and Scopus databases followed PRISMA guidelines, including all peer-reviewed studies in languages understood by the authors. Thirty-five publications met inclusion criteria, including 1373 women and 148 newborns. Studies varied substantially in design and methodology, so classical meta-analysis was not possible. Therefore, results were categorized, analysed and summarised in text and tables.

RESULTS

Infusions of synthetic oxytocin increased maternal plasma oxytocin levels dose-dependently; doubling the infusion rate approximately doubled oxytocin levels. Infusions below 10 milliunits per minute (mU/min) did not raise maternal oxytocin above the range observed in physiological labour. At high intrapartum infusion rates (up to 32 mU/min) maternal plasma oxytocin reached 2-3 times physiological levels. Postpartum synthetic oxytocin regimens used comparatively higher doses with shorter duration compared to labour, giving greater but transient maternal oxytocin elevations. Total postpartum dose was comparable to total intrapartum dose following vaginal birth, but post-caesarean dosages were higher. Newborn oxytocin levels were higher in the umbilical artery vs. umbilical vein, and both were higher than maternal plasma levels, implying substantial fetal oxytocin production in labour. Newborn oxytocin levels were not further elevated following maternal intrapartum synthetic oxytocin, suggesting that synthetic oxytocin at clinical doses does not cross from mother to fetus.

CONCLUSIONS

Synthetic oxytocin infusion during labour increased maternal plasma oxytocin levels 2-3-fold at the highest doses and was not associated with neonatal plasma oxytocin elevations. Therefore, direct effects from synthetic oxytocin transfer to maternal brain or fetus are unlikely. However, infusions of synthetic oxytocin in labour change uterine contraction patterns. This may influence uterine blood flow and maternal autonomic nervous system activity, potentially harming the fetus and increasing maternal pain and stress.

Fetal Movement Counting in Prolonged Pregnancies: The COMPTAMAF Prospective Randomized Trial

In prolonged pregnancies, the risks of neonatal morbidity and mortality are increased. The aim of this trial was to assess the benefits of maternal information about fetal movement (FM) counting on neonatal outcomes in prolonged pregnancy. It was a prospective, single center, randomized, open-label study conducted from October 2019 to March 2022. Intention-to-treat analyses were performed on 278 patients randomized into two 1:1 groups (control group and FM counting group). The primary outcome was a composite score of neonatal morbidity (presence of two of the following items: fetal heart rate abnormality at delivery, Apgar score of <7 at 5 min, umbilical cord arterial pH of <7.20, and acute respiratory distress with mutation in neonatal intensive care unit). There was no significant difference between the two groups in the rate of neonatal morbidity (14.0% in the FM counting group versus 22.9% in the standard information group; p = 0.063; OR 0.55, 95% CI 0.29−1.0). In this study, fetal movement counting for women in prolonged pregnancy failed to demonstrate a significant reduction in adverse neonatal outcomes.

Association of labour duration in spontaneous deliveries with low neonatal Apgar scores and foetal acidosis: the Japan Environment and Children's Study

This study evaluated the association between labour duration (LD) and incidence of low neonatal Apgar scores and foetal acidosis. Data of 37,682 women with full-term singleton spontaneous vaginal deliveries from the Japan Environment and Children's Study were analysed. Women were classified according to the median LD as nulliparous (< 10 or ≥ 10 h) or multiparous (< 5 or ≥ 5 h) and further into five subcategories: nulliparous (< 10.0, 10.0-12.9, 13.0-15.9, 16.0-18.9, and ≥ 19 h) and multiparous (< 5.0, 5.0-7.9, 8.0-10.9, 11.0-13.9, and ≥ 14.0 h). Multiple logistic regression models were used to determine odds ratios (ORs) for outcomes in women with over-median LD. Over-median LD exhibited no statistically significant association with low neonatal Apgar scores. The adjusted ORs for both umbilical artery (UmA-pH) < 7.2 and < 7.1 were increased in nulliparous women with over-median LD, whereas only the adjusted OR for UmA-pH < 7.2 was increased in multiparous women with over-median LD. Moreover, this association manifested as a plateau in nulliparous women with LD ≥ 13 h and without dose-dependent association in multiparous women.

Comparison of phase rectified signal averaging and short term variation in predicting perinatal outcome in early onset fetal growth restriction

OBJECTIVES

To compare short term variation (STV) and phase rectified signal averaging (PRSA) and their association with fetal outcome in early onset fetal growth restriction (FGR).

METHODS

Data were used from a retrospective cohort study of women who were admitted for FGR and/or pre-eclampsia and who were delivered by pre-labor Cesarean section or had a fetal death before 32 weeks' gestation. Computerized cardiotocography (cCTG) registrations of the 5 days before delivery or fetal death were used for calculation of STV and PRSA. PRSA was expressed as the average acceleration capacity (AAC) and average deceleration capacity (ADC). FHR decelerations were classified visually as absent, 1-2 per hour or recurrent. Abnormality of STV and of PRSA was either analyzed as a single parameter or in combination with recurrent decelerations. Endpoints were defined as composite adverse condition at birth consisting of fetal death, low Apgar score, low umbilical pH, the need for resuscitation after birth and as major neonatal morbidity or neonatal death.

RESULTS

Included were 367 pregnancies of which 20 resulted in fetal death. An abnormal cCTG with either recurrent decelerations and/or low STV or recurrent decelerations and/or low PRSA were similarly associated with composite adverse condition at birth (n=99), but neither with major neonatal morbidity.

CONCLUSIONS

PRSA and STV have similar efficacy for measuring fetal heart rate variation in early onset FGR. An increased risk of a composite adverse condition at birth is indicated by a low value of either parameter and/or the presence of recurrent decelerations.

Association of fetal heart rate short term variability pattern during term labor with neonatal morbidity and small for gestational age status

OBJECTIVE

To assess the association of fetal heart rate short-term variability (STV) pattern during term labor with both neonatal composite morbidity (cord blood pH ≤ 7.10 and/or neonatal intensive care unit admission and/or Apgar score at 5 min <7) and small for gestational age (SGA) status.

STUDY DESIGN

Retrospective cohort in a single academic institution between January 2016 and December 2018. A total of 1896 women that delivered a singleton during labor in cephalic presentation after 37 weeks of gestation were included (948 women with SGA neonates and 948 women with appropriate weight for gestational age (AGA) neonates that were matched to women with SGA neonates based on maternal age, parity, induction of labor, gestational diabetes, gestational age at delivery and a history of one cesarean section using propensity score matching). STV was compared at labor onset (cervical dilation ≤ 4 cm), in the first stage of labor (cervical dilation = 6 cm) and in the second stage of labor (cervical dilation = 10 cm). A generalized linear mixed model was used to assess the association between SGA status, neonatal composite morbidity and STV.

RESULTS

After adjustment for maternal origin, term, gestational diabetes, labor length, SGA status was not associated with any change in STV during labor (mean adjusted STV: -0.20 ms, 95 %CI[-0.58-0.17], p = 0.284 at labor onset, 0.29 ms, 95 %CI[-0.1- 0.68], p = 0.155, in the first stage of labor and 0.36 ms, 95 %CI[-0.02-0.74], p = 0.065 in the second stage of labor). In case of neonatal composite morbidity mean adjusted STV was lower in the first stage of labor (mean adjusted STV: -1.29 ms, 95 %CI[-2.1 - -0.43], p = 0.003) and in the second stage of labor (mean adjusted STV: -1.15 ms, 95 %CI[-1.96 - -0.34], p = 0.005). The results were similar with the addition of delivery mode and meconium-stained amniotic fluid in the model or non-reassuring fetal heart rate and meconium-stained amniotic fluid.

CONCLUSIONS

This work suggests that STV decrease during term labor is associated with fetal well-being, independently of fetal weight. This suggests that further prospective studies should consider the evaluation of this parameter in the prediction of neonatal compromise.

Umbilical Cord Blood Acid-Base Parameters and Lactate as Predictors of Subsequent Meconium Aspiration Syndrome in Neonates

Meconium aspiration syndrome (MAS) in neonates born through meconium-stained amniotic fluid (MSAF) causes significant morbidity and mortality. Early recognition of at-risk neonates could help optimize treatment. The aim was to determine predictive characteristics of cord blood pH, base deficit and lactate with subsequent MAS. Receiver operating characteristic (ROC) curves with area under curve (AUC) were estimated. Among 231 MSAF complicated pregnancies, 25 (10.8%) had MAS. Mean cord pH was significantly lower in neonates with MAS compared to those without MAS (7.15 ± 0.11 vs. 7.26 ± 0.07; p < 0.001). Median lactate between the two groups [5.6 (7.5, 3.7) vs. 2.7 (4.5, 2.0)] and base deficit [-10.6 (-13.2, -4.2) vs. -3.7 (-6.3, -2.6)] also differed significantly (p = 0.01). ROC curve area for cord lactate, pH, and base deficit were 0.81, 0.79, and 0.75, respectively. The predictive cutoff values for pH, lactate, and base deficit were 7.20, 3.55 mmol/L, and -5.3 mmol/L, respectively.

Development of a comprehensive database for research on foetal acidosis

OBJECTIVE

To develop a research database for mother-and-child clinical and laboratory data and digital foetal heart rate (FHR) recordings.

METHODS

The Base Bien Naître (BBN) database was derived from a single-centre health data warehouse. It contains exhaustive data on all parturients with a singleton pregnancy, a vaginal or caesarean delivery in labour with a cephalic presentation after at least 37 weeks of amenorrhea, and a live birth between February 1st, 2011, and December 31st, 2018. On arrival in the delivery room, the FHR was recorded digitally for at least 30 min. A cord blood sample was always taken in order to obtain arterial pH (pHa). More than 6,000 recordings were analyzed visually for the risk of foetal acidosis and classified into five groups (according to the French College of Gynaecologists and Obstetricians (CNGOF) classification) or three groups (according to the International Federation of Gynaecology and Obstetrics (FIGO) classification).

RESULTS

Of the 16,089 files in the health data warehouse, 11,026 were complete and met the BBN's inclusion criteria. The FHR digital recordings were of good quality, with low signal loss (median [interquartile range]: 7.0% [4.3;10.9]) and a median recording time of 304 min [190;438]). In 3.7% of the children, the pHa was below 7.10. We selected a subset of 6115 records with good-quality FHR recordings over 120 min and reliable cord blood gas data: 692 (11.3%) had at least a significant risk of acidosis (according to the CNGOF classification), and 1638 (26.8%) were at least suspicious (according to the FIGO classification).

CONCLUSION

The BBN database has been designed as a searchable tool with data reuse. It currently contains over 11,000 records with comprehensive data.

Paracetamol preceding very preterm birth: Is it safe?

INTRODUCTION

The use of paracetamol for pain relief in pregnancy is common. However, the influence of paracetamol on the perinatal adaptation of high-risk infants has not been studied. These data are important for safety, since another inhibitor of prostaglandin synthesis is harmful to infants born very preterm and increases serious morbidity. We studied whether the use of paracetamol had an adverse influence on neonatal adaptation and the outcomes of infants during the first hospitalization.

MATERIAL AND METHODS

We studied the patient records of high-risk mothers and their infants born before 32 weeks of gestation for multiple variables over a period of 84 months in Oulu University Hospital, a regional tertiary care hospital caring for high-risk deliveries and providing neonatal intensive care. In a matched cohort setting, the exposition was defined as paracetamol use <24 h before childbirth. The controls had consumed no paracetamol up to 1 week before delivery. Infants with major anomalies were excluded. The primary outcome was defined as the need for early interventional treatments for the preterm infants. Outcomes during the first hospitalization were also studied.

RESULTS

Altogether, 170 fetuses from 149 mothers were exposed to paracetamol during the study period. The control population, delivering during the same period, consisted of 118 non-exposed fetuses from 104 mothers. Among them, the mothers were pairwise matched according to their medications, amniotic fluid leakage time, clinical infections, and delivery mode. After matching, 72 mothers/group remained, resulting in 88 paracetamol-exposed infants and 85 controls. No perinatal adverse reactions were detected. There were no differences in either circulatory support during the first postnatal day or in the risk for major diseases during the first hospitalization. Paracetamol-exposed infants needed fewer acute delivery room therapies (51.1% vs. 65.9%, mean difference -14.89; 95% confidence interval -0.29 to -0.003). Maternal total paracetamol dose in the 1 week before delivery correlated positively with Apgar scores.

CONCLUSIONS

Antenatal paracetamol given within 24 h before birth had no adverse effects on extremely or very preterm infants. The long-term safety of paracetamol and the potential acute benefits for preterm infants during perinatal transition remain to be proven in larger, prospective settings.

Acid base and blood gas analysis in term neonates immediately after birth with uncomplicated neonatal transition

BACKGROUND

Acid base and blood gas measurements provide essential information, especially in critically ill neonates. After birth, rapidly changing physiology and difficulty to obtain blood samples represent unique challenges.

OBJECTIVES

The aim of the present study was to establish normal values of capillary acid base and blood gas analysis immediately after birth in term neonates after uncomplicated neonatal transition.

METHOD

This is a post-hoc-analysis of ancillary outcome parameter of a prospective observational study in term neonates immediately after caesarean section. Neonates were included after immediate neonatal transition without need of medical support and a capillary blood sample was taken by a heel-stick within 15-20 minutes after birth.

RESULT

One hundred thirty-two term neonates were included with mean (SD) gestational age of 38.7 ± 0.7 weeks. The blood was drawn mean (SD) 16 ± 1.7 minutes after birth. The mean (SD) values of the analyses were: pH 7.30 ± 0.04, pCO₂ 52.6 ± 6.4, base excess - 0.9 ± 1.7 and bicarbonate 24.8 ± 1.6.

CONCLUSION

This is the first study describing acid base and blood gas analyses in term neonates immediately after birth with uncomplicated neonatal transition.

Short-term morbidity and types of intrapartum hypoxia in the newborn with metabolic acidaemia: a retrospective cohort study

Objectives

To assess labour characteristics in relation to the occurrence of Composite Adverse neonatal Outcome (CAO) within a cohort of fetuses with metabolic acidaemia.

Design

Retrospective cohort study.

Setting

Three Italian tertiary maternity units.

Population

431 neonates born with acidaemia ≥36 weeks.

Methods

Intrapartum CTG traces were assigned to one of these four types of labour hypoxia: acute, subacute, gradually evolving and chronic hypoxia. The presence of CAO was defined by the occurrence of at least one of the following: Sarnat Score grade ≥2, seizures, hypothermia and death <7 days from birth.

Main outcome measures

To compare the type of hypoxia on the intrapartum CTG traces among the acidaemic neonates with and without CAO.

Results

The occurrence of a CAO was recorded in 15.1% of neonates. At logistic regression analysis, the duration of the hypoxia was the only parameter associated with CAO in the case of an acute or subacute pattern (odds ratio [OR] 1.3; 95% CI 1.02–1.6 and OR 1.04; 95% CI 1.0–1.1, respectively), whereas both the duration of the hypoxic insult and the time from PROM to delivery were associated with CAO in those with a gradually evolving pattern (OR 1.13; 95% CI 1.01–1.3 and OR 1.04; 95% CI 1.0–1.7, respectively). The incidence of CAO was higher in fetuses with chronic antepartum hypoxia than in those showing CTG features of intrapartum hypoxia (64.7 vs. 13.0%; P < 0.001).

Conclusions

The frequency of CAO seems related to the duration and the type of the hypoxic injury, being higher in fetuses showing CTG features of antepartum chronic hypoxia.

Tweetable abstract

This study demonstrates that in a large population of neonates with metabolic acidaemia at birth, the overall incidence of short‐term adverse outcome is around 15%. Such risk seems closely correlated to the duration and the type of hypoxic injury, being higher in fetuses admitted in labour with antepartum chronic hypoxia than those experiencing intrapartum hypoxia.

This study demonstrates that in a large population of neonates with metabolic acidaemia at birth, the overall incidence of short‐term adverse outcome is around 15%. Such risk seems closely correlated to the duration and the type of hypoxic injury, being higher in fetuses admitted in labour with antepartum chronic hypoxia than those experiencing intrapartum hypoxia.

Umbilical cord arterial blood lactate dehydrogenase and pH as predictors of perinatal outcome in high-risk term pregnancies: A cohort study

BACKGROUND

Birth asphyxia is a common cause of perinatal morbidity, mortality.

OBJECTIVE

To compare the efficacy of umbilical cord arterial blood lactate dehydrogenase (LDH) and pH as predictors of neonatal outcome in high-risk term pregnancies using receiver operating characteristic (ROC) curves.

MATERIAL AND METHODS

Present retrospective cohort study was conducted in the rural tertiary centre of Northern India over two years (January 2017-December 2018). Neonates delivered to 300 term (≥37 - ≤42 weeks) high-risk antenatal women were enrolled after fulfilling inclusion criteria. Immediately after delivery of a newborn by any mode, the segment of the umbilical cord (10 cm) was double clamped, cut, and arterial blood samples were taken for LDH and pH and were compared with neonatal outcome. Statistical analysis was done using SPSS 22.0 software.

RESULTS

For all 300 neonates mean ± SD values of cord blood LDH and pH were 545.19 ± 391.93 U/L and 7.13 ± 0.15, respectively. High cord blood lactate and low pH values were significantly associated with adverse neonatal outcomes including neonatal resuscitation, NICU admission, complications and early neonatal deaths (p=0.000). The sensitivity, specificity and negative predictive value of cord blood LDH in the prediction of neonatal death was 100.00%, 53.17%, 100%, and pH was 93.75%, 53.17%, 99.34%, respectively.

CONCLUSION

Cord blood lactate and pH help in the early prediction of neonatal outcomes, but cord blood lactate is a better predictor.

Perinatal hypoxia and the risk of severe Molar-Incisor Hypomineralisation (MIH): a retrospective analysis of the pH value of umbilical arterial blood after birth

PURPOSE

Molar-Incisor Hypomineralisation (MIH) remains a widespread developmental disorder of the teeth with a still largely unknown etiology. Perinatal events were blamed in previous studies for the development of MIH. The aim of the present study was to evaluate the influence of perinatal hypoxia-determined by the pH value of the umbilical cord blood-and to investigate its correlation with severe MIH retrospectively. In addition, cesarean section was recorded as differentiation variable.

METHODS

A total number of 138 children (mean age 8.0 years ± 1.7), who were treated for severe MIH in a dental office in Berlin between the years 2008 and 2019, were included in the study. The control group was comprised of patients with the same date of birth (44 children, mean age 7.7 years ± 1.7). Information on the pH value of the arterial blood from the umbilical cord taken immediately after birth, whose recording is mandatory in Germany, was received from the parents by letter survey requesting the entries from the German Child Health Booklet.

RESULTS

In the group of the male children born without cesarean section, the pH value of the control group was significantly lower (7.19 ± 0.09) than the pH value of the MIH group (7.27 ± 0.07, p = 0.0008). In female children born with or without cesarean section as well as in male children born by cesarean section there were no significant differences between the MIH and control group.

CONCLUSIONS

No significant association between MIH and the pH value of the umbilical cord blood or birth by cesarean section could be found in the examined patient population.

Is acidemia at birth a risk factor for functional gastrointestinal disorders?

Functional gastrointestinal disorders (FGIDs) are common in early childhood. It has been demonstrated that neonatal acidemia at delivery can lead to significant neonatal morbidity. The primary aim of this study was to evaluate the relationship between acidemia at birth and the development of FGIDs, as regurgitation, colic, and constipation, in term infants. Term newborns born at the Foggia University Hospital, Italy during the year 2020 were included in the study. As per routine clinical practice, a cord blood gas analysis on a blood sample drawn from the umbilical artery (UA) of each infant immediately after birth was performed, and Apgar score was recorded. One year after birth, each infant's parents were interviewed through a phone call to investigate development of FGIDs, feeding practices, and morbidities. During the study period, 1574 term newborns met the inclusion criteria. The prevalence of infantile colic, regurgitation, and constipation was higher in infants with low UA pH (colic 51.5% vs. 25.4%, p < 0.001; regurgitation 30.6% vs. 15.2%, p < 0.001; constipation 24.6% vs. 16.0%, p = 0.015), with infants having moderate-severe acidemia facing the highest risk for all the examined FGIDs. In binary logistic regression analyses, UA pH and perinatal antibiotic exposure proved to be independently associated with the later diagnosis of each FGID.

CONCLUSION

Newborns with acidemia at birth appear to face a higher risk of FGIDs in infancy. Avoiding low cord blood pH should continue to be the goal for obstetricians, while enhanced long-term surveillance for infants who experienced birth acidemia should be required.

WHAT IS KNOWN

• Cord blood gas analysis is recommended in all high-risk deliveries, and in some centers, it is performed after all deliveries. • Neonatal acidemia at birth has been linked to adverse outcomes, mainly neurological. Recently, perinatal asphyxia has been reported to increase the risk of developing necrotizing enterocolitis in term infants.

WHAT IS NEW

• An association between acidemia at birth and risk of developing FGIDs such as regurgitation and colic during the first year of life had never been described so far. • An increased surveillance of infants with low UA pH at birth may be beneficial and could allow for early detection of any of the reported FGIDs.

Can we improve our ability to interpret category II fetal heart rate tracings using additional clinical parameters?

OBJECTIVES

This study examined predictive factors, in addition to Category II Fetal Herat Rate (FHR) monitoring that might imply fetal acidosis and risk of asphyxia.

METHODS

This retrospective cohort study compared three groups of patients with Category II FHR monitoring indicating need for imminent delivery. Groups were divided based on fetal cord blood pH: pH≤7.0, 7.0<pH<7.2 and pH≥7.2. Demographics, medical history, delivery data and early neonatal outcomes were reviewed.

RESULTS

The cohort included 417 women. Nine (2.2%) had cord pH≤7.0, 105 (25.2%) pH 7.0 to 7.2 and 303 (72.6%) ad pH≥7.2. Background characteristics, pregnancy follow-up and intrauterine fetal evaluation prior to delivery were similar in all groups. As expected, more patients in the low pH group had cesarean section (55.6%), than vaginal delivery or vacuum extraction (p=0.02). Five-minute Apgar scores were similar in all groups.

CONCLUSIONS

This retrospective study did not detect a specific parameter that could help predict the prognosis of fetal acidosis and risk of asphyxia. As we only included patients with a Category II tracing that was worrisome enough to lead to imminent delivery, it is reasonable to believe that this is due to patient selection, meaning that when the Category II FHR results in decision for prompt delivery, there is no added value in additional clinical characteristics. The evaluation should be expanded to all patients with Category II tracing for better interpretation tools for Category II FHR monitors, as well as a larger study population.

Adverse obstetric outcomes in early-diagnosed gestational diabetes mellitus: The Japan Environment and Children's Study

AIMS/INTRODUCTION

To examine adverse outcomes in women with early-diagnosed gestational diabetes mellitus using data from a large birth cohort study in Japan.

MATERIALS AND METHODS

This study analyzed data from singleton pregnancies in the Japan Environment and Children's Study including births during 2011-2014. Mothers with an HbA1c level ≥6.5% in the first trimester, a history of diabetes mellitus, or steroid use during pregnancy were excluded. The participants were divided into three groups: control (without gestational diabetes mellitus), early-diagnosed gestational diabetes mellitus (diagnosed before gestational week 24), and late-diagnosed gestational diabetes mellitus (diagnosed after gestational week 24). Multiple logistic regression analysis was performed to calculate the risk of early-diagnosed and late-diagnosed gestational diabetes mellitus for adverse obstetrics outcomes.

RESULTS

In total, 100,376 eligible participants were included in this study. The number of individuals in control cases, early-diagnosed gestational diabetes mellitus cases, and late-diagnosed gestational diabetes mellitus cases was 98,090 (97.7%), 751 (0.7%), and 1,535 (1.5%), respectively. When control cases were used as reference, multiple logistic regression analysis revealed that early-diagnosed gestational diabetes mellitus increased the risk of hypertensive disorders of pregnancy (adjusted odds ratio: 2.08, 95% confidence interval: 1.51-2.86), early-onset hypertensive disorders of pregnancy (adjusted odds ratio: 1.91, 95% confidence interval: 1.01-3.65), and late-onset hypertensive disorders of pregnancy (adjusted odds ratio: 1.92, 95% confidence interval: 1.29-2.86).

CONCLUSION

Early-diagnosed gestational diabetes mellitus is associated with serious obstetric complications. Our findings indicate the necessity of further investigations to validate the benefit of early screening for gestational diabetes mellitus in pregnant women.

Umbilical cord prolapse: revisiting its definition and management

Umbilical cord prolapse is an unpredictable obstetrical emergency with an incidence ranging from 1 to 6 per 1000 pregnancies. It is associated with high perinatal mortality, ranging from 23% to 27% in low-income countries to 6% to 10% in high-income countries. In this review, we specifically addressed 3 issues. First, its definition is not consistent in the current literature, and "occult cord prolapse" is a misnomer because the cord is still above the cervix. We proposed that cord prolapse, cord presentation, and compound cord presentation should be classified according to the positional relationship among the cord, the fetal presenting part, and the cervix. All of them may occur with either ruptured or intact membranes. The fetal risk is highest in cord prolapse, followed by cord presentation, and lastly by compound cord presentation, which replaces the misnomer "occult cord prolapse." Second, the mainstay of treatment of cord prolapse is urgent delivery, which means cesarean delivery in most cases, unless vaginal delivery is imminent. The urgency depends on the fetal heart rate pattern, which can be bradycardia, recurrent decelerations, or normal. It is most urgent in cases with bradycardia, because a recent study showed that cord arterial pH declines significantly with the bradycardia-to-delivery interval at a rate of 0.009 per minute (95% confident interval, 0.0003-0.0180), and this may indicate an irreversible pathology such as vasospasm or persistent cord compression. However, cord arterial pH does not correlate with either deceleration-to-delivery interval or decision-to-delivery interval, indicating that intermittent cord compression causing decelerations is reversible and less risk. Third, while cesarean delivery is being arranged, different maneuvers should be adopted to relieve cord compression by elevating the fetal presenting part and to prevent further cord prolapse beyond the vagina. A recent study showed that the knee-chest position provides the greatest elevation effect, followed by filling of the maternal urinary bladder with 500 mL of fluid, and then the Trendelenburg position (15°) and other maneuvers. However, each maneuver has its own advantages and limitations; thus, they should be applied wisely and with great caution, depending on the actual clinical situation. Therefore, we have proposed an algorithm to guide this acute management.

Proposed cutoff for fetal scalp blood lactate in intrapartum fetal surveillance based on neonatal outcomes: a large prospective observational study

OBJECTIVE

Determination of lactate in fetal scalp blood (FBS) during labour has been recognised since the 1970s. The internationally accepted cutoff of >4.8 mmol/l indicating fetal acidosis is exclusive for the point-of-care device (POC) LactatePro™, which is no longer in production. The aim of this study was to establish a new cutoff for scalp lactate based on neonatal outcomes with the use of the StatstripLactate^® /StatstripXpress^® Lactate system, the only POC designed for hospital use.

DESIGN

Observational study.

SETTING

January 2016 to March 2020 labouring women with indication for FBS were prospectively included from seven Swedish and one Australian delivery unit.

POPULATION

Inclusion criteria: singleton pregnancy, vertex presentation, ≥35⁺⁰  weeks of gestation.

METHOD

Based on the optimal correlation between FBS lactate and cord pH/lactate, only cases with ≤25 minutes from FBS to delivery were included in the final calculations.

MAIN OUTCOME MEASURES

Metabolic acidosis in cord blood defined as pH <7.05 plus BD_ecf >10 mmol/l and/or lactate >10 mmol/l.

RESULTS

A total of 3334 women were enrolled of whom 799 were delivered within 25 minutes. The areas under the receiver operating characteristics curves (AUC) and corresponding optimal cutoff values were as follows; metabolic acidosis AUC 0.87 (95% CI 0.77-0.97), cutoff 5.7 mmol/l; pH <7.0 AUC 0.83 (95% CI 0.68-0.97), cutoff 4.6 mmol/l; pH <7.05 plus BD_ecf ≥12 mmol/l AUC 0.97 (95% CI 0.92-1), cutoff 5.8 mmol/l; Apgar score <7 at 5 minutes AUC 0.74 (95% CI 0.63-0.86), cutoff 5.2 mmol/l; and pH <7.10 plus composite neonatal outcome AUC 0.76 (95% CI 0.67-0.85), cutoff 4.8 mmol/l.

CONCLUSION

A scalp lactate level <5.2 mmol/l using the StatstripLactate^® /StatstripXpress^® system will safely rule out fetal metabolic acidosis.

TWEETABLE ABSTRACT

Scalp blood lactate <5.2 mmol/l using the StatstripLactate^® /StatstripXpress system has an excellent ability to rule out fetal acidosis.

Effects of acute tocolysis using ritodrine hydrochloride on foetal heart rate patterns in intrauterine foetal resuscitation: a retrospective, single-centre observational study

No consistent recommendations concerning the preferred tocolytic agents for intrauterine foetal resuscitation are available. We evaluated the effects of acute tocolysis (AT) using ritodrine hydrochloride on foetal heart rate (FHR) patterns and neonatal outcomes. We retrospectively analysed the data of patients undergoing emergency caesarean section because of non-reassuring foetal status indicated by foetal scalp electrodes. Patients were classified into AT (ritodrine hydrochloride approximately 500 µg/min) and control groups with 15 and 12 participants, respectively. FHR patterns, Apgar scores, umbilical arterial analysis, and neonatal admission were compared. All participants had FHR category II; decelerations disappeared in all foetuses in the AT group, with no significant difference in neonatal outcomes. The AT group had a higher baseline FHR and lower short-term FHR variability than the control group, indicating foetal autonomic responses. Further studies are needed to clarify the effects of AT on FHR patterns, neonatal outcomes, and foetal and neonatal autonomic responses.Impact statementWhat is already known on this subject? The usefulness of acute tocolysis using ritodrine hydrochloride has been well-documented in several studies; however, such an application often induces side effects, such as maternal tachycardia, palpitations, and tremors.What the results of this study add? The short-term administration of ritodrine hydrochloride eliminated decelerations, with no significant difference in neonatal outcomes in pregnant women with foetal heart rate category II. Meanwhile, there were higher foetal heart rate and lower short-term foetal heart rate variability in pregnant women administered with ritodrine hydrochloride, indicating foetal autonomic responses.What the implications are of these findings for clinical practice and/or further research? Ritodrine hydrochloride administration, even for short-term, appears to be associated with foetal autonomic responses. Further studies with stratification of patient groups based on the severity and aetiology of non-reassuring foetal status, including pregnant women with foetal category III, would elucidate the risk and benefit of acute tocolysis using ritodrine hydrochloride, based on foetal heart rate patterns, neonatal outcomes, and foetal and neonatal autonomic responses.

Antenatal screening of small for gestational age: Impact on obstetrical management and neonatal outcomes in case of trial of labor after 37 weeks

OBJECTIVE

Antenatal screening of small fetuses for gestational age (SGA) is a public health challenge. The aim of this study is to assess the obstetrical management and the immediate neonatal outcomes, according to the antenatal screening of the SGA fetuses.

METHODS

We performed a retrospective study in a French tertiary care hospital between January 1, 2016 and December 31, 2018. Women were eligible if they had a monofetal pregnancy with a fetus in head presentation and a trial of labor after 37 weeks. A fetus was considered SGA when the estimated fetal weight was less than the 10^th percentile at the third trimester ultrasound. A newborn was considered hypotrophic when the birthweight was less than the 10th percentile.

RESULTS

8 153 newborns were included and 948 of the newborns were hypotrophic (308 were suspected for SGA, 640 were not suspected for SGA) and 7205 were eutrophic. Among the hypotrophic neonates, we observed no significant difference regarding the immediate neonatal outcomes between the two groups of fetuses suspected and not suspected for SGA. Among the fetuses not suspected for SGA, the rate of arterial umbilical cord pH below 7.10 was significantly higher in the hypotrophic newborns compared to the non hypotrophic newborns (4.7% vs 3.1%, p = 0.041).

CONCLUSION

In our population, unsuspected fetal hypotrophy may be associated with an increased risk of neonatal acidosis. These results emphasize the benefit of improving prenatal screening to identify the SGA fetuses.

Mild Neonatal Acidemia is Associated with Neonatal Morbidity at Term

OBJECTIVE

The aim of this study is to determine the association between mild acidemia (umbilical artery [UA] pH: 7.11-7.19) and neonatal morbidity in neonates at term.

STUDY DESIGN

This is a secondary analysis of a prospective cohort of women admitted for labor at ≥37 weeks of gestation within a single institution from 2010 to 2015. Universal umbilical cord blood gas assessment was performed and validated. A composite neonatal morbidity index was created including respiratory distress, mechanical ventilation, meconium aspiration syndrome, suspected or confirmed sepsis, hypoxic-ischemic encephalopathy, need for therapeutic hypothermia, seizures and death. The cohort was stratified by UA pH into normal (≥7.20), mild acidemia (7.11-7.19), acidemia (7.00-7.10), and severe acidemia (≤7.00). A subanalysis was also performed where neonates with UA pH between 7.11 and 7.19 were further stratified into two groups (7.11-7.14 and 7.15-7.19) to determine if mildly acidotic infants at the lower end of the pH range were at increased risk of morbidity. Multivariable logistic regression was used to estimate the association between UA pH and neonatal morbidity.

RESULTS

Among 6,341 participants, 614 (9.7%) had mild acidemia. These infants were more likely to experience morbidity compared with those with normal UA pH (adjusted odds ratio [aOR]: 2.14; [1.68-2.73]). Among neonates with mild acidemia, UA pH 7.11 to 7.14 was associated with increased risk of composite neonatal morbidity (aOR: 3.02; [1.89-4.82]), as well as respiratory distress and suspected or confirmed sepsis when compared with UA pH 7.15 to 7.19.

CONCLUSION

These data demonstrate that term neonates with mild acidemia at birth are at higher odds for short-term morbidity compared with neonates with normal UA pH. Furthermore, among neonates with mild acidemia, those with lower UA pH had worse neonatal outcomes than those with higher UA pH. This suggests that closer evaluation of neonates with UA pH higher than traditionally used could allow for earlier detection of morbidity and possible intervention.

KEY POINTS

· Neonates with mild acidemia (umbilical artery [UA] pH: 7.11-7.19) demonstrated an increased risk of composite morbidity compared with those with normal UA pH (≥7.20).. · Among neonates with mild acidemia, those with lower UA pH (7.11-7.14) had a greater risk of morbidity compared with those with higher UA pH (7.15-7.19), suggesting a progression of risk of morbidity as UA pH decreases.. · The majority of prior research has focused on severe acidemia (UA pH ≤ 7.00) using outcomes of severe neurologic morbidity and mortality. These data suggest that an increased risk of morbidity exists at higher pH values when more proximal and less severe outcomes are included, such as respiratory distress and neonatal sepsis..

The Term Newborn: Delivery Room Triage and Transitions of Care

Term newborn infants without significant medical problems usually transition from fetal to newborn life without medical assistance. Infants requiring therapy often need care in a neonatal intensive care unit as opposed to a well-baby unit. Infants with unclear physiologic status or disease that may require therapies in the immediate newborn period may benefit from a period of observation with close monitoring before admission to a well-baby unit. Whenever possible, providing care for a newborn infant in an area that provides care for the newborn and mother together in the same room facilitates adaptation to normal breastfeeding and family bonding.

Teenage pregnancy as a risk factor for placental abruption: Findings from the prospective Japan environment and children's study

Objective

Placental abruption is a significant obstetric complication that affects both maternal and neonatal mortality and morbidity. The present study examined the effect of maternal age on the incidence of placental abruption.

Methods

We used data of singleton pregnancies from the Japan Environment and Children’s Study, which was a prospective birth cohort study conducted between January 2011 and March 2014 across 15 regional centers in Japan. A multiple regression model was used to identify whether maternal age (<20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years) is a risk factor for placental abruption. The analyses were conducted while considering the history of placental abruption, assisted reproductive technology, number of previous deliveries, smoking during pregnancy, body mass index before pregnancy, and chronic hypertension.

Results

A total of 94,410 Japanese women (93,994 without placental abruption and 416 with placental abruption) were recruited. Herein, 764, 8421, 25915, 33517, and 25793 women were aged <20 years, 20–24 years, 25–29 years, 30–34 years, and ≥35 years, respectively. Besides advanced maternal age (≥35 years; adjusted odds ratio: 1.7, 95% confidence interval: 1.1–2.5), teenage pregnancy was also a risk factor for placental abruption (adjusted odds ratio: 2.8, 95% confidence interval: 1.2–6.5) when the maternal age of 20–24 years was set as a reference.

Conclusions

In the Japanese general population, besides advanced maternal age, teenage pregnancy was associated with placental abruption. Recently, the mean maternal age has been changing in Japan. Therefore, it is important for obstetric care providers to provide proper counseling to young women based on up-to-date evidence.

Forensic Analysis of Umbilical and Newborn Blood Gas Values for Infants at Risk of Cerebral Palsy

Cerebral palsy litigation cases account for the highest claims involving obstetricians/gynecologists, a specialty that ranks among the highest liability medical professions. Although epidemiologic studies indicate that only a small proportion of cerebral palsy (10-20%) is due to birth asphyxia, negligent obstetrical care is often alleged to be the etiologic factor, resulting in contentious medical-legal conflicts. Defense and plaintiff expert opinions regarding the etiology and timing of injury are often polarized, as there is a lack of established methodology for analysis. The objective results provided by umbilical cord and newborn acid/base and blood gas values and the established association with the incidence of cerebral palsy provide a basis for the forensic assessment of both the mechanism and timing of fetal neurologic injury. Using established physiologic and biochemical principles, a series of case examples demonstrates how an unbiased expert assessment can aid in both conflict resolution and opportunities for clinical education.

The Impact of Pregnancy on Outcomes After Bariatric Surgery

BACKGROUND

Bariatric surgery is performed mostly on obese women of reproductive age. Many studies have analyzed pregnancy outcomes after bariatric surgery, but only a small number have studied the impact of pregnancy on the postoperative outcomes.

PURPOSE

To study the effect of pregnancy on outcomes after bariatric surgery in women of childbearing age.

METHODS

From January 2010 to October 2017, a retrospective study of a prospectively maintained database was conducted at the University Hospital of Geneva (HUG), where 287 women between the ages of 18 and 45 years had undergone Roux-en-Y gastric bypass (RYGB). A comparison of the results during a 5-year follow-up was performed between women who became pregnant after their bariatric surgery (pregnancy group, n = 40) and postoperative non-pregnant women (non-pregnancy group, n = 247). The two groups were compared for weight loss, complications, and nutritional deficiencies.

RESULTS

The pregnancy group was significantly younger (29.2 ± 5.5 vs. 36.4± 6.3 years, p < 0.001) and heavier (124.0 ± 18.0 kg vs. 114.7 ± 17.1, p < 0.001) compared with the non-pregnancy group at the time of surgery. The percentage of excess BMI loss (%EBMI loss) was similar in both groups during the 5-year follow-up. Complications after RYGB and nutritional deficiencies were nearly identical in the two groups. The interval of time between bariatric surgery and first pregnancy was a median of 20.8 months. Out of 40 first pregnancies, 28 women completed pregnancy successfully with live birth.

CONCLUSION

Pregnancy after bariatric surgery is safe and does not adversely affect outcomes after RYGB.

Maternal pre-pregnancy body mass index and foetal acidosis in vaginal and caesarean deliveries: The Japan Environment and Children's Study

A high maternal body mass index (BMI) is associated with increased risks of asphyxia-related neonatal morbidity. We evaluated the association between maternal pre-pregnancy BMI and foetal acidosis while accounting for the mode of delivery. Participants from the Japan Environment and Children's Study with singleton pregnancies after 22 weeks of gestation who gave birth during 2011-2014 were included. The participants (n = 71,799) were categorised into five groups according to the pre-pregnancy BMI: G1 (BMI < 18.5 kg/m2), G2 (18.5 to < 20.0 kg/m2), G3 (20.0 to < 23.0 kg/m2), G4 (23.0 to < 25.0 kg/m2), and G5 (≥ 25.0 kg/m2). Foetal acidosis was defined as umbilical artery pH (UmA-pH) < 7.20 or < 7.10. Multiple logistic regression analyses were used to evaluate the effect of pre-pregnancy BMI on foetal acidosis risk, accounting for the mode of delivery. In Japanese women, pre-pregnancy BMI ≥ 25.0 kg/m2 significantly increased the likelihood of foetal acidosis in newborns delivered vaginally. We found no association between pre-pregnancy BMI and foetal acidosis in newborns delivered via caesarean section. Counselling for body weight control before pregnancy and adequate management and selection of the mode of delivery in pregnant women with a high BMI who are in labour may be essential to avoid foetal acidosis.

Predicting long-term neurodevelopmental outcomes in very preterm neonates by umbilical cord gas parameters

BACKGROUND

The predictive value of acidemia at birth on long-term neurodevelopmental outcomes remains poorly understood, especially in preterm neonates.

OBJECTIVE

This study aimed to assess the relationship between the umbilical artery acid-base status and major neurodevelopmental disability at an age of between 5 and 8 years among children born very prematurely.

STUDY DESIGN

We performed a secondary analysis of the data from a follow-up study of a prospective cohort of 457 children aged between 23 weeks and 31 weeks and 6 days from 1996 to 2001. Arterial cord gas parameters that were <10th percentile in the original cohort of 457 neonates (ie, pH of <7.1, base deficit of <-8.6 mEq/L, and a partial pressure of CO2 of >77 mm Hg) were considered abnormal. Sensitivity analyses considered alternative definitions for abnormal cord gases including a pH of <7.0 or base deficit of <-12 mEq/L. The primary outcome was a composite of major neurodevelopmental disability, including an intelligence quotient score of <70, cerebral palsy, blindness, deafness, abnormal balance, impaired cognition, dystonia, and seizure disorder. A logistic regression analysis was used to adjust for race and caregiver intelligence quotient score and, in an additional analysis, for gestational age.

RESULTS

A total of 259 of 261 maternal-infant dyads were evaluated at a mean child age of 6.8 years, with complete umbilical cord gas data for 228 of those. Infants with an abnormal pH and a base deficit (defined above) were over 4-fold more likely to have the composite disability and an intelligence quotient score of <70. These increased odds persisted after adjusting for age and caregiver intelligence quotient score, but when considering gestational age as well, none of the umbilical cord gas parameters significantly predicted the presence of the composite disability or an intelligence quotient score of <70. However, when using the stricter umbilical cord gas criteria (ie, pH of <7.0 and a base deficit of <-12 mEq/L), a base deficit of <-12 mEq/L was independently associated with both neurodevelopmental disability and an intelligence quotient score of <70.

CONCLUSION

When defined more strictly, abnormal umbilical cord gases, specifically a base deficit of <-12 mEq/L, are associated with an increased risk for major long-term neurodevelopmental disability and an intelligence quotient score of <70 in children born very prematurely.

Effect of Different Positions During Surgical Preparation With Combined Spinal-Epidural Anesthesia for Elective Cesarean Delivery: A Randomized Controlled Trial

BACKGROUND

The intraoperative 15° left-tilt position during cesarean delivery has more recently been questioned regarding its effect on fetal acid-base balance and is a frequent source of complaints by surgeons. We hypothesized that a 30° left-tilt position during surgical preparation could improve the acid-base balance of the fetus compared with the 15° left-tilt or supine position during surgical preparation.

METHODS

Women undergoing elective cesarean delivery under combined spinal epidural anesthesia were randomized to a supine position, 15° left-lateral tilt position or 30° left-lateral tilt position; the position was changed to supine before the incision. Anesthetic management was standardized and included fluid loading with 10 mL/kg of normal saline followed by colloid loading. Hypotension (systolic blood pressure [SBP] reduction >20% baseline value or SBP <90 mm Hg) was treated with boluses of phenylephrine or ephedrine according to maternal heart rate. The primary outcome was umbilical arterial blood pH and the secondary outcomes included maternal SBP within 15 minutes after induction of anesthesia, the amount of vasoactive drug administered before end of the surgery, and the incidence of hypotension during cesarean delivery.

RESULTS

Seventy-five patients were included. After testing by analysis of variance, there was no significant difference in the umbilical arterial pH among the 3 groups (supine group: 7.31 ± 0.03 vs 15° group: 7.30 ± 0.04 vs 30° group: 7.31 ± 0.02, P = .28). The 30° group required significantly less phenylephrine (P = .007) and ephedrine (P = .005) before the end of surgery than the supine group; however, the only benefit observed in the 15° group was that the mean SBP at 3 minutes after spinal injection was significantly improved compared with the supine group.

CONCLUSIONS

Compared with the supine position, the 30° left-tilt position during surgical preparation did not significantly improve the fetal acid-base status, but it significantly reduced the use of phenylephrine and ephedrine and reduced the incidence of hypotension; however, these benefits were not observed in the 15° left-tilt group.

Umbilical cord lactate compared with pH as predictors of intrapartum asphyxia

Despite advances in fetal monitoring during labor, one of the most critical causes of neonatal death and neurologic injuries remains intrapartum asphyxia. Umbilical cord gases can be used to detect acidosis and fetal distress. We conducted a retrospective, multicenter study to evaluate umbilical cord blood pH and lactate as a mean of evaluating the degree of intrapartum hypoxia and also to establish which of the two is more reliable in predicting morbidity in term neonates. The present study utilized a total of 124 cases that met the criteria for intrapartum asphyxia and 150 normal term newborns that were randomly selected as case control. Both umbilical cord lactate and pH proved to be accurate predictors of neonatal morbidity caused by intrapartum hypoxia. Lactate proved to be superior to pH in predicting adverse neonatal outcome. The greatest sensibility and specificity in predicting intrapartum asphyxia were achieved in our study by using a cutoff value of 3.75 mmol/l for lactate and 7.24 for pH.

Gestational weight gain and foetal acidosis in vaginal and caesarean deliveries: The Japan Environment and Children's Study

Inappropriate gestational weight gain (GWG), either above or below the recommended values, has been associated with an increased risk of adverse obstetric outcomes. To evaluate the risks of GWG for foetal acidosis according to pre-pregnancy body mass index (BMI) and mode of delivery, we analysed women with singleton pregnancies between 2011 and 2014 in the Japan Environment and Children’s Study. Participants (n = 71,799) were categorised according to pre-pregnancy BMI. GWG was categorised into insufficient, appropriate, or excessive. Foetal acidosis was defined as umbilical artery pH (UmA-pH) < 7.20 or < 7.10. Multiple logistic regressions were performed for each BMI category to identify the risks of GWG for foetal acidosis, accounting for the mode of delivery. Excessive GWG was significantly associated with increased foetal acidosis in overweight women and in women whose pre-pregnancy BMI was 23.0–25.0 kg/m² especially in those with vaginal deliveries. Conversely, excessive GWG was not significantly associated with increased foetal acidosis in obese women and in women whose pre-pregnancy BMI was  ≥ 25.0 kg/m².

Dietary Inflammatory Index during Pregnancy and the Risk of Intrapartum Fetal Asphyxia: The Japan Environment and Children's Study

We aimed to examine the impact of a daily pro-inflammatory diet during pregnancy on intrapartum fetal acidemia using a large birth cohort study in Japan. We used data on singleton pregnancies in the Japan Environment and Children’s Study (JECS) involving births from 2011 to 2014 through vaginal delivery to calculate the maternal dietary inflammatory index (DII). Participants were categorized according to DII quintiles. A multiple logistic regression model was used to estimate the risk of a pro-inflammatory diet on fetal umbilical artery pH. In total, 56,490 participants were eligible for this study. Multiple regression analysis showed that nulliparous women who had undergone vaginal delivery and were consuming a pro-inflammatory diet had an increased risk of pH < 7.10 (adjusted odds ratio [aOR]: 1.64, 95% confidence interval [CI]: 1.12–2.39). Among these women, the risk of pH < 7.10 was not affected by the duration of labor (aOR: 1.64, 95% CI: 1.11–2.42). In conclusion, following a pro-inflammatory diet during pregnancy is a risk factor for fetal acidosis among nulliparous women undergoing vaginal delivery. A high DII diet during pregnancy may modify the intrapartum fetal heart rate pattern via intrauterine inflammation.

The Effect of Maternal Pulmonary Function Test Parameters on Umbilical Cord Blood Gas and the Duration of Labor

OBJECTIVE

To evaluate the relationship between the maternal pulmonary function test (PFT) and the Apgar score of the newborn, umbilical cord blood (UCB) gas values and the duration of delivery.

MATERIAL AND METHODS

The present study included 41 volunteer nulliparous pregnant women who presented to our obstetrics clinic and PFTs were performed by using spirometry.

RESULTS

A significant positive correlation was observed between 5^th-minute Apgar scores and maternal FEV1 (forced expiratory volume in the first second) (lt), FEV1%, FVC (lt), FVC% (r=0.509, p=0.003; r=0.47, p=0.007; r=0.434, p=0.013; r=0.417, p=0.017; respectively). A significant positive correlation was observed between UCB pH value and maternal FEV1 (lt), FVC (lt) (r=0.515, p=0.003; r=0.351, p=0.049; respectively).

CONCLUSION

Our results showed that FEV1 and FVC values, which indicate maternal respiratory functions, may affect Apgar scores of the newborn and UCB gas values.

Head Ultrasound Resistive Indices Are Associated With Brain Injury on Diffusion Tensor Imaging Magnetic Resonance Imaging in Neonates With Hypoxic-Ischemic Encephalopathy

BACKGROUND

Neonatal hypoxic-ischemic encephalopathy (HIE) is associated with dysfunctional cerebral autoregulation. Resistive index (RI) measured in the anterior cerebral artery on transfontanellar head ultrasound is a noninvasive measure of blood flow and may indicate autoregulation dysfunction. We tested whether RI was associated with brain injury on diffusion tensor imaging magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Seventy-five neonates who underwent therapeutic hypothermia for HIE were enrolled. Resistive index values were obtained from head ultrasound performed at the end of therapeutic hypothermia. Apparent diffusion coefficient scalars were measured on MRIs performed before day of life 10.

RESULTS

Lower RI was associated with lower apparent diffusion coefficient in the centrum semiovale, basal ganglia, thalamus, and posterior limb of the internal capsule. Combining RI and Apgar scores improved the ability to distinguish injury severity on MRI relative to either metric alone.

CONCLUSIONS

Low RI correlated with worse brain injury on diffusion tensor imaging and may serve as an early marker of brain injury in cooled HIE neonates.

Effect of Delayed Cord Clamping on Umbilical Blood Gas Values in Term Newborns: A Systematic Review

OBJECTIVE

To compare the effect of delayed cord clamping on cord blood gas values in vaginally delivered, healthy, term singletons.

DATA SOURCE

We used MEDLINE, CINAHL, CENTRAL, EMBASE, and ClinicalTrials.gov databases.

METHODS OF STUDY SELECTION

Eligible studies included randomized controlled trials (RCTs) comparing cord blood gas values obtained from early compared with delayed cord clamping groups and observational studies using serial cord blood gas from the same umbilical cord. We described the difference in means of cord blood gas parameters and comparative descriptive statistics when a difference in means was not available. We used a domain-based risk bias tool to extract methodologic details and assess potential risk of bias.

TABULATION, INTEGRATION, AND RESULTS

This review included two RCTs and three observational studies. These studies included a total of 234 newborns with early cord clamping and 218 newborns with delayed cord clamping. The observational studies showed that 45-90 seconds delayed cord clamping was associated with mean decreases in umbilical arterial pH (0.02-0.03), HCO3 (0.3-0.8 mmol/L) and increases in base deficit (0.3-1.3 mmol/L) compared with early cord clamping. One observational study showed that delayed cord clamping was associated with decreases in umbilical venous pH (0.01) and HCO3 (0.2 mmol/L) and increase in venous base deficit (0.1-0.3 mmol/L) compared with early cord clamping. These changes were not observed in the two RCTs.

CONCLUSION

Delayed cord clamping up to 120 seconds has either no effect or only a small effect on cord blood acid-base balance; overall, the magnitude of these changes is not clinically significant in vaginally delivered, healthy, term singletons.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42019135779.

Physioxia enhances T-cell development ex vivo from human hematopoietic stem and progenitor cells

Understanding physiologic T-cell development from hematopoietic stem (HSCs) and progenitor cells (HPCs) is essential for development of improved hematopoietic cell transplantation (HCT) and emerging T-cell therapies. Factors in the thymic niche, including Notch 1 receptor ligand, guide HSCs and HPCs through T-cell development in vitro. We report that physiologically relevant oxygen concentration (5% O₂ , physioxia), an important environmental thymic factor, promotes differentiation of cord blood CD34+ cells into progenitor T (proT) cells in serum-free and feeder-free culture system. This effect is enhanced by a potent reducing and antioxidant agent, ascorbic acid. Human CD34+ cell-derived proT cells in suspension cultures maturate into CD3+ T cells in an artificial thymic organoid (ATO) culture system more efficiently when maintained under physioxia, compared to ambient air. Low oxygen tension acts as a positive regulator of HSC commitment and HPC differentiation toward proT cells in the feeder-free culture system and for further maturation into T cells in the ATO. Culturing HSCs/HPCs in physioxia is an enhanced method of effective progenitor T and mature T-cell production ex vivo and may be of future use for HCT and T-cell immunotherapies.

Computerized fetal heart rate analysis in early preterm fetal growth restriction

OBJECTIVE

To assess the value of computerized cardiotocography (cCTG) with calculation of fetal heart rate (FHR) short-term variability (STV) in early preterm fetal growth restriction (FGR) for prevention of fetal death and neonatal asphyxia, neonatal morbidity, and 2-year neurodevelopmental impairment.

METHODS

This was a retrospective cohort study of all women who were admitted to the Amsterdam University Medical Center-AMC between 2003 and 2015 due to FGR and/or pre-eclampsia, and who were delivered by prelabor Cesarean section, or had a fetal death, before 32 weeks' gestation. STV of all available cCTG registrations during the 5 days preceding fetal death or delivery was calculated retrospectively, and FHR decelerations were classified visually as absent, 1-2/h or recurrent (> 2/h). Adverse outcome endpoints were defined as fetal death, neonatal asphyxia at birth (including fetal death), neonatal death, major neonatal morbidity and 2-year neurodevelopmental outcome. A simulation analysis was performed to assess the incidence of adverse outcome using two thresholds for cCTG: (1) highly abnormal (STV < 2.6 ms before 29 weeks and < 3.0 ms thereafter, and/or recurrent FHR decelerations); and (2) moderately abnormal (STV < 3.5 ms before 29 weeks and < 4.0 ms thereafter, and/or recurrent FHR decelerations). Three management strategies were assessed using a strict schedule for the frequency of cCTG recordings: (1) cCTG without use of fetal arterial Doppler; (2) cCTG with additional fetal arterial Doppler after 29 weeks; and (3) cCTG with additional fetal arterial Doppler after 27 weeks.

RESULTS

Included were 367 pregnancies (3295 cCTG recordings), of which 20 resulted in fetal death and 347 were delivered by Cesarean section before the onset of labor. Cesarean delivery was indicated by fetal condition in 94% of cases and by maternal condition in 6%. Median gestational age at delivery was 30 (interquartile range (IQR), 28-31) weeks and median birth weight was 900 (IQR, 740-1090) g. Six cases of fetal death were not anticipated by standard practice using visual assessment of CTG. A last highly abnormal cCTG was associated with fetal death and with neonatal asphyxia (including fetal death; n = 99), but not with major neonatal morbidity and 2-year neurodevelopmental outcome. Moderately abnormal cCTG had no significant association with any endpoint. Simulation analysis showed that a strategy that combined cCTG results with umbilicocerebral ratio or umbilical absent or reversed end-diastolic flow could detect all fetal deaths.

CONCLUSIONS

Computerized CTG in combination with fetal arterial Doppler, with a strict protocol for the frequency of recordings, is likely to be more effective than visual CTG assessment for preventing fetal death in early preterm FGR. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Umbilical cord arterial blood gas analysis in term singleton pregnancies: a retrospective analysis over 11 years

Objective

Given that the large volume of data on cord arterial blood gas analysis (ABGA) have been rarely addressed in Korean population, we aimed to examine the incidence, associated factors, and neonatal outcomes in cases of low cord pH, and investigate the incidence of cerebral palsy (CP).

Methods

From data of all consecutive term singleton pregnancies delivered in our institution from 2006 to 2016 (n=15,701), cases with cord ABGA (n=14,221) available were included. We collected information on maternal clinical characteristics and delivery outcomes and also examined neonatal and infant outcomes, including neonatal intensive care unit (NICU) admission and CP, in cases with low cord pH, defined as a pH <7.1.

Results

Rates of low Apgar scores at 1 minute (<4) and 5 minutes (<7) were 0.6% (n=79) and 0.4% (n=58), respectively. Rates of cord pH <7.2, <7.1, and <7.0 were 7.1% (n=1,011), 1.1% (n=163), and 0.3% (n=38), respectively. Among cases with low cord pH, 30.1% (n=49/163) were admitted to the NICU and 11.0% (n=18/163) required ventilator support. Ultrasonography of the brain was performed in 28.8% (n=47/163), with abnormal findings observed in 27.7% (n=13/47). Among cases with low cord pH, 1.8% (n=3/163) were subsequently diagnosed with CP, including 2 cases of spastic CP and 1 of ataxic CP.

Conclusion

Although low cord pH was a relatively frequent finding observed in 1 out of every 87 cases, hypoxic-ischemic encephalopathy-related CP was found in only 1 out of 7,111 term singleton deliveries over 11 years in our institution.