Metabolic acidosis at birth and suboptimal care - illustration of the gap between knowledge and clinical practice

Umbilical arterial blood lactate as predictor of early neonatal outcome and evaluation of intrapartum asphyxia

Background

Perinatal asphyxia is a leading cause of under-5 mortality and exerts great pressure on the health system. Adequate foetal monitoring in labour is paramount in the early detection of foetal distress to prevent perinatal asphyxia. Several methods of foetal monitoring are in use with varying efficacy. This study investigated the efficacy of umbilical arterial (UA) lactate assay in predicting adverse perinatal outcomes.

Methodology

This was a prospective longitudinal study involving 160 pregnant women in the active phase of labour at term who met the inclusion criteria. They were recruited using a consecutive sampling technique and underwent a cardiotocography. Then they were classified into normal and abnormal cardiotocographic groups. At delivery, the UA blood of all of the babies was collected and assayed for serum lactate, and the levels were correlated with the perinatal outcome. The perinatal outcomes were measured by Apgar scores, admission into the neonatal unit, and hypoxic ischaemic encephalopathy. Analysis was done to determine the sensitivity and specificity of UA lactate in predicting birth asphyxia, hypoxic ischaemic encephalopathy, and neonatal unit admission.

Results

The mean age ± standard deviation (SD) between the two cardiotocography (CTG) groups, normal years (30.55 ± 5.59) and abnormal years (29.86 ± 5.51), were similar. A critical UA lactate concentration > 9.1 mmol/L predicted Apgar scores < 7 at 5 min with a sensitivity and specificity of 76.47% (CI: 50.1-93.2) and 91.55% (CI: 85.7-95.6%), respectively. Also, the need for neonatal unit admission was predicted at a cut-off point >9.1 mmol/L with a sensitivity of 61.90% (CI: 38.4-81.9) and specificity of 91.30% (CI: 85.3-95.4). Umbilical artery lactate levels > 11.2 mmol/L predicted the development of hypoxic ischaemic encephalopathy in neonates with a sensitivity of 100% (CI: 39.8-100.0) and specificity of 88.39% (CI: 82.3-93.0).

Conclusion

Umbilical artery lactate correlates with adverse pregnancy outcomes and is an excellent tool for predicting adverse neonatal outcome.

Uterine contractile activity and neonatal outcome - A blind analysis of a randomized controlled trial cohort

INTRODUCTION

Sufficient contractions are necessary for a successful delivery but each contraction temporarily constricts the oxygenated blood flow to the fetus. Individual fetal or placental characteristics determine how the fetus can withstand this temporary low oxygen saturation. However, only a few studies have examined the impact of uterine activity on neonatal outcome and even less attention has been paid to parturients' individual characteristics. Our objective was therefore to find out whether fetuses compromised by maternal or intrapartum risk factors are more vulnerable to excessive uterine activity.

MATERIAL AND METHODS

Uterine contractile activity was assessed by intrauterine pressure catheters. Women (n = 625) with term singleton pregnancies and fetus in cephalic presentation were included in this secondary, blind analysis of a randomized controlled trial cohort. Intrauterine pressure as Montevideo units (MVU), contraction frequency/10 min and uterine baseline tone were calculated for 4 h prior to birth or the decision to perform cesarean section. Uterine activity in relation to umbilical artery pH linearly or ≤7.10 was used as the primary outcome. Need for operative delivery (either cesarean section or vacuum-assisted delivery) due to fetal distress was analyzed as a secondary outcome. In addition, belonging to vulnerable subgroups with, for example, chorioamnionitis, hypertensive or diabetic disorders, maternal smoking or neonatal birthweight <10th percentile were investigated as additional risk factors.

RESULTS

A linear decline in umbilical artery pH was seen with increasing intrauterine pressure in all deliveries (p < 0.001). Among parturients with suspected chorioamnionitis, every increasing 10 MVUs increased the likelihood of umbilical artery pH ≤7.10 (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.02-1.34, p = 0.023). The need for operative delivery due to fetal distress was increased among all laboring women by every increasing 10 MVUs (OR 1.05, 95% CI 1.01-1.09, p = 0.015). This association with operative deliveries was further increased among parturients with hypertensive disorders (OR 1.23, 95% CI 1.05-1.43, p = 0.009) and among those with diabetic disorders (OR 1.13, 95% CI 1.04-1.28, p = 0.003).

CONCLUSIONS

Increasing intrauterine pressure impairs umbilical artery pH especially among parturients with suspected chorioamnionitis. Fetuses in pregnancies affected by chorioamnionitis, hypertensive or diabetic disorders are more vulnerable to high intrauterine pressure.

Risk factors for seizures in the vigorous term neonate: A population-based register study of singleton births in Sweden

Background

Neonatal seizures have been associated with increased mortality and impaired neurodevelopment and, knowledge about risk factors may be useful for prevention. Clear associations have been established between labor-related risk factors and seizures in asphyxiated neonates. However, there is limited information about why some vigorous term-born infants experience seizures.

Objectives

Our aim was to assess antepartum and intrapartum risk factors for seizures in vigorous term-born neonates.

Methods

This was a national cohort study of singleton infants born at term in Sweden from 2009–2015. Vigorous was defined as an Apgar score of at least 7 at 5 and 10 minutes. Data on the mothers and infants were obtained from the Swedish Medical Birth Register and the Swedish Neonatal Quality Register. A diagnosis of neonatal seizures was the main outcome measure and the exposures were pregnancy and labor variables. Logistic regression analysis was used and the results are expressed as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Results

The incidence of neonatal seizures was 0.81/1,000 for 656 088 births. Seizures were strongly associated with obstetric emergencies (aOR 4.0, 95% CI 2.2–7.4), intrapartum fever and/or chorioamnionitis (aOR 3.4, 95% CI 2.1–5.3), and intrapartum fetal distress (aOR 3.0, 95% CI 2.4–3.7). Other associated intrapartum factors were: labor dystocia, occiput posterior position, operative vaginal delivery, and Cesarean delivery. Some maternal factors more than doubled the risk: a body mass of more than 40 (aOR 2.6, 95% CI 1.4–4.8), hypertensive disorders (aOR 2.3, 95% CI 1.7–3.1) and diabetes mellitus (aOR 2.6, 95% CI 1.7–4.1).

Conclusion

A number of intrapartum factors were associated with an increased risk of seizures in vigorous term-born neonates. Obstetric emergencies, intrapartum fever and/or chorioamnionitis and fetal distress were the strongest associated risks. The presence of such factors, despite a reassuring Apgar score could prompt close surveillance.

Hypoxic ischemic encephalopathy in offspring of immigrant women in Sweden: A population-based cohort study

INTRODUCTION

One in four women giving birth in Sweden is foreign-born. Immigrant status has been suggested as a risk factor for adverse perinatal outcomes. It is not known if infants to foreign-born women have an increased risk of severe birth asphyxia, or which factors might mediate such association.

MATERIAL AND METHODS

A population-based cohort study of 726 730 live births at 36 weeks of gestation or more in Sweden in 2009-2015. The exposure was maternal country of birth, grouped according to the World Bank country classification: low-, lower-middle, upper-middle, and high-income economies. The main outcome was neonatal hypoxic ischemic encephalopathy (HIE). The outcome was estimated by severity and classified as non-hypothermia-treated HIE, representing mainly mild cases, and hypothermia-treated HIE, representing moderate to severe cases. A secondary outcome was low Apgar score at 5 minutes, defined as <7 or <4. Odds ratios with 95% CI were calculated, using Swedish-born women as the reference. Structural equation modeling was used to investigate potential mediation of known antepartum risk factors.

RESULTS

A total of 854 infants were diagnosed with HIE and 398 received therapeutic hypothermia. Offspring of mothers born in low-income countries had the highest incidences of HIE and low Apgar score, with an incidence of therapeutic hypothermia of 1.1 per 1000. Compared with offspring of Swedish-born mothers, these neonates had an almost two-fold increased risk of HIE, with or without hypothermia treatment (odds ratio 1.7; 95% CI 1.2-2.7 and odds ratio 1.7; 95% CI 1.2-2.6, respectively), and a 2- to 3-fold increased risk of low Apgar score. The structural equation model analysis indicated an exclusive direct effect of country of birth on HIE. Factors reflecting socio-economic status mediated a small proportion of the risk of Apgar score <7 at 5 minutes.

CONCLUSIONS

Offspring of women born in low-income countries had associations with severe birth asphyxia, with increased risk of both HIE and low Apgar score at 5 minutes. The associations seemed only to be marginally mediated by other antepartum factors. The associations are complex and further studies are needed to find explanatory and potentially preventable factors.

Evaluation and impact of fetal physiology training on fetal heart rate analysis

INTRODUCTION

Evaluation of fetal well-being during labor is based on fetal heart rate (FHR) analysis, which requires physiology expertise. The aim of the present study was to assess medical residents' fetal physiology training in terms of theoretical knowledge, FHR interpretation, and use of second-line examinations.

METHODS

This single-center, prospective study of obstetrics and gynecology residents (N = 34) at CHU de Lille Hospital (Lille, France) was conducted from November 2017 to November 2018. Evaluation and training were conducted in three stages. First, residents' pre-training knowledge of FHR interpretation and use of fetal scalp blood sampling (FBS) was assessed using clinical cases. Second, a didactic training session on fetal physiology was delivered. Finally, post-training knowledge was evaluated using the same cases presented during pre-training. I: Pre-training, 3%, 11.8%, and 14.7% of residents considered their training on fetal physiology, FHR analysis, and second-line examinations, respectively, to be sufficient. Training significantly improved their theoretical knowledge, which was assessed using multiple-choice questions (median [interquartile range]: 1.5 [1.0-2.0] vs. 4.0 [3.0-4.5], p<0.001), and reduced the number of FBS requested (36.3% vs. 29.5%, p = 0.002). Krippendorff's alpha coefficient for the reproducibility of residents' responses improved significantly, reflecting greater homogenization of clinical practice decisions (alpha [95% confidence interval]: 0.60 [0.55-0.65] vs. 0.72 [0.67-0.76]).

CONCLUSION

Improved fetal physiology knowledge promotes more accurate FHR interpretation, better indications for second-line examinations, and greater homogenization of clinical practice decisions. Future studies should evaluate the impact of fetal physiology training on clinical practice.

Preventing the human factor: organizational aspects linked to fetal asphyxia

BACKGROUND

Perinatal asphyxia can cause cerebral palsy and hypoxic - ischemic encephalopathy. They are public health problems because they cause permanent disability.

METHODS

This is a retrospective, analytical, observational study. 162 cases of mothers whose children experienced fetal asphyxia were compare to 361 controls where this condition did not occur. The variables analyzed were classified as: prepartum, intrapartum and organizational.

RESULTS

Assisted Reproductive Technology obtained pregnancies, smoking, maternal body mass index, lack of one to one assistance during labor, birth on a day of high volume activity increased the risk of fetal asphyxia, as well as other traditionally linked factors like shoulder distocia or age over 35 years.

CONCLUSIONS

Cerebral palsy cannot always be prevented because it is a syndrome with a multitude of potential causes. But a small number of cases is likely to be linked to acute intrapartum events that could be limited by changing organizational policies such as staff training and implementing team work and discussion. Our paper proposes strategies to try and modify organizational risk factors and therefore limit the incidence of fetal asphyxia.

Intrapartum uterine activity and neonatal outcomes: a systematic review

BACKGROUND

Increased uterine activity (UA) may not allow adequate recovery time for foetal oxygenation.

METHODS

The aim of the study was to determine if increased UA during labour is associated with an increased risk of either short- or long-term neurological injury in term neonates, or with neonatal proxy measures of intrapartum hypoxia-ischemia. MEDLINE, CINAHL, and ClinicalTrials.gov were searched using the following terms: uterine activity, excessive uterine activity, XSUA, uterine hyperstimulation, and tachysystole. Any study that analysed the relationship between UA during term labour and neurological outcomes/selected proxy neurological outcomes was eligible for inclusion. Outcomes from individual studies were reported in tables and presented descriptively with odds ratios (OR) and 95% confidence intervals (CI) for dichotomous outcomes and means with standard deviations for continuous outcomes. Where group numbers were provided, ORs and their CIs were calculated according to Altman.

MAIN RESULTS

Twelve studies met the inclusion criteria. Seven studies featured umbilical artery pH as an individual outcome. Umbilical artery base excess and Apgar scores were both reported as individual outcomes in four studies. No study examined long term neurodevelopmental outcomes and only one study reported on encephalopathy as an outcome. The evidence for a relationship between UA and adverse infant outcomes was inconsistent. The reported estimated effect size varied from non-existent to clinically significant.

CONCLUSIONS

There is some evidence that increased UA may be a non-specific predictor of depressed neurological function in the newborn, but it is inconsistent and insufficient to support the conclusion that an association generally exists.

Changes in labor outcomes after implementing structured use of oxytocin augmentation with a 4-hour action line

Introduction: Oxytocin augmentation is essential in labor management, but how to optimize its use is still debated. Joint international guidelines regarding prolonged labor and the use of oxytocin augmentation are still not available. Due to its potential harmful side effects, a decreased use of oxytocin is encouraged. We aimed to implement a structured protocol on the use of oxytocin augmentation and to observe changes in labor outcomes.Materials and methods: The protocol was implemented at the Obstetric Department of Sørlandet Hospital, Kristiansand, Norway on 1 January 2012; therefore, data from the hospital were collected prospectively and compared for two time-period cohorts: the historic control cohort (2009-2010) and the study period cohort (2012-2013). The structured protocol instructs, and restricts, the birth attendants to diagnose prolonged labor, by protocol definition only, before commencing oxytocin infusion for augmentation. Nulliparous women with singleton, term deliveries (≥37 weeks), cephalic presentation, and spontaneous onset of labor (Ten-Group Classification System (TGCS) group 1) were included in the analysis. The main outcome was use of oxytocin augmentation.Results: The study cohort and control cohort comprised 1103 (26.2%) and 1399 (33.1%) of all laboring women, respectively (p < .01). The protocol was followed satisfactorily in 78% of the study cohort. The use of oxytocin augmentation was reduced in the study cohort versus the control cohort; 41.3 versus 48.9% (p < .01); mean oxytocin infusion duration was shorter (100 versus 123 min; p < .01); and mean total oxytocin dose decreased (1009 versus 1293 mU; p < .01). The cesarean section rate was 5.9% in the study cohort versus 8.0% in the control cohort (p = .04). The estimated mean duration of the active phase of labor increased by 47 min (p < .01) after the implementation. The frequency of estimated postpartum hemorrhage >1000 ml was higher, 4.9 versus 2.0% (p < .01), but the use of blood transfusions remained stable, 2.5 versus 2.7% (p = .78), the study cohort versus control cohort, respectively.Conclusions: Implementation of a protocol of structured use of oxytocin augmentation reduced the frequency, dosage, and duration of oxytocin without increasing the cesarean section rate in TGCS group 1.

High-dose versus low-dose of oxytocin for labour augmentation: a randomised controlled trial

PROBLEM

Delayed labour progress is common in nulliparous women, often leading to caesarean section despite augmentation of labour with synthetic oxytocin.

BACKGROUND

High- or low-dose oxytocin can be used for augmentation of delayed labour, but evidence for promoting high-dose is weak. Aim To ascertain the effect on caesarean section rate of high-dose versus low-dose oxytocin for augmentation of delayed labour in nulliparous women. Methods Multicentre parallel double-blind randomised controlled trial (ClinicalTrials.gov: NCT01587625) in six labour wards in Sweden. Healthy nulliparous women at term with singleton cephalic fetal presentation, spontaneous labour onset, confirmed delay in labour and ruptured membranes (n=1351) were randomised to labour augmentation with either high-dose (6.6 mU/minute) or low-dose (3.3 mU/minute) oxytocin infusion.

FINDINGS

1295 women were included in intention-to-treat analysis (high-dose n=647; low-dose n=648). Caesarean section rates did not differ between groups (12.4% and 12.3%, 95% Confidence Interval -3.7 to 3.8). Women with high-dose oxytocin had: shorter labours (-23.4min); more uterine tachysystole (43.2% versus 33.5%); similar rates of instrumental vaginal births, with more due to fetal distress (43.8% versus 22.7%) and fewer due to failure to progress (39.6% versus 58.8%). There were no differences in neonatal outcomes.

DISCUSSION

Our study could not confirm results of two systematic reviews indicating, with weak evidence, that use of high-dose oxytocin was associated with lower frequency of caesarean section.

CONCLUSION

We found no advantages for routine use of high-dose oxytocin in the management of delay in labour. Low-dose oxytocin regimen is recommended to avoid unnecessary events of tachysystole and fetal distress.

[Fetal heart rate analysis: Evaluation of an in situ training program on cardiotocography interpretation during labor in the Auvergne-Rhône-Alpes region (France)]

OBJECTIVES

To evaluate an in situ training program on caradiotocography interpretation during labor in the Auvergne-Rhône-Alpes region (France).

METHODS

Fifteen hospital maternity unit took part to an "outreach visit" training on fetal cardiotocography interpretation between November 2011 and 2015. Professionals were asked to answer to a 10 questions test based on the French classification of fetal heart rate, at inclusion (Test 0: T0), immediately after (Test 1: T1), and long time after the training (Test 2: T2). The mean score for each maternity (T0, T1, T2) was compared individually. Subgroup analysis considered the level of perinatal care of each maternity (level 1 or 2) and the type of practice (public or private).

RESULTS

The study included 332 healthcare professionals belonging to 8 level 1 (53.5%) and 7 level 2 (47.7%) maternity units. The T0 mean score was 4.79 (IC 95% [4.54; 5.02]) instead of 6.71(IC 95% [6.49; 6.93]) at T1 (P<0.05). Seventeen professionals (22.9%) answered T2 with a mean time of 35.2 months (Median value: 40 months) and a mean score of 5.32. The mean score was significantly higher at T2 than at T0 (5.32-IC 95%[4.94-5.70] (P<0.001) but lower than the score at T1 (P<0.05).

CONCLUSION

An "outreach visit" training on fetal cardiotocography interpretation improves theknowledge of healthcare professionals at short and long term.

Umbilical lactate as a measure of acidosis and predictor of neonatal risk: a systematic review

BACKGROUND

Umbilical cord lactate is one approach to measuring acidosis and intrapartum hypoxia, knowledge of which may be helpful for clinicians involved in the care of women and newborns.

OBJECTIVE

To synthesise the evidence on accuracy of umbilical cord lactate in measuring acidosis and predicting poor neonatal outcome.

SEARCH STRATEGY

Studies published and unpublished between 1990 and 2014 from PubMed/Medline, EMBASE, Cochrane Central Register of Controlled Trials, and clinicaltrials.gov were assessed.

SELECTION CRITERIA

Cross-sectional and randomised studies that assessed fetal acidosis (using lactate as the index test) with or without an assessment of neonatal outcome.

DATA COLLECTION AND ANALYSIS

Correlations between index and reference test(s) were recorded, as were the raw data to classify the predictive ability of umbilical lactate for neonatal outcomes. Meta-analysis of correlation was performed. We plotted estimates of the studies' observed sensitivities and specificities on Forest plots with 95% confidence intervals (CI). Where possible, we combined data using meta-analysis, applying the hierarchical summary receiver operating characteristics model and a bivariate model.

MAIN RESULTS

Twelve studies were included. Umbilical lactate correlated with pH [pooled effect size (ES) -0.650; 95% CI -0.663 to -0.637, P < 0.001], base excess (ES -0.710; 95% CI -0.721 to -0.699, P < 0.001), and Apgar scores at 5 minutes (ES 0.300; 95% 0.193-0.407, P < 0.001). Umbilical lactate had pooled sensitivity and specificity for predicting neonatal neurological outcome including hypoxic ischaemic encephalopathy of 69.7% (95% CI 23.8-94.4%) and 93% (95% CI 86.8-96.3%).

AUTHORS' CONCLUSION

Umbilical cord lactate is a clinically applicable, inexpensive and effective way to measure acidosis and is a tool that may be used in the assessment of neonatal outcome.

TWEETABLE ABSTRACT

Umbilical cord lactate: a clinically applicable, inexpensive, effective way to measure intrapartum acidosis.

A policy of routine umbilical cord blood gas analysis decreased missing samples from high-risk births

AIM

This study compared obstetric units practicing routine or selective umbilical cord blood gas analysis, with respect to the risk of missing samples in high-risk deliveries and in infants with birth asphyxia.

METHODS

This was a Swedish population-based cohort study that used register data for 155 235 deliveries of live singleton infants between 2008 and 2014. Risk ratios and 95% confidence intervals were calculated to estimate the association between routine and selective umbilical cord blood gas sampling strategies and the risk of missing samples.

RESULTS

Selective sampling increased the risk ratios when routine sampling was used as the reference, with a value of 1.0, and these were significant in high-risk deliveries and birth asphyxia. The risk ratios for selective sampling were large-for-gestational age (9.07), preterm delivery at up to 36 weeks of gestation (8.24), small-for-gestational age (7.94), two or more foetal scalp blood samples (5.96), an Apgar score of less than seven at one minute (2.36), emergency Caesarean section (1.67) and instrumental vaginal delivery (1.24).

CONCLUSION

Compared with routine sampling, selective umbilical cord blood gas sampling significantly increased the risks of missing samples in high-risk deliveries and in infants with birth asphyxia.

Labor stimulation with oxytocin: effects on obstetrical and neonatal outcomes

OBJECTIVE

to evaluate the effects of labor stimulation with oxytocin on maternal and neonatal outcomes.

METHOD

descriptive and analytical study with 338 women who gave birth at a tertiary hospital. Obstetric and neonatal variables were measured and compared in women submitted and non-submitted to stimulation with oxytocin. Statistics were performed using Chi-square test, Fisher exact test, Student t-test; and crude Odds Ratio with 95% confidence interval were calculated. A p < 0.05 was considered statistically significant.

RESULTS

stimulation with oxytocin increases the rates of cesarean sections, epidural anesthesia and intrapartum maternal fever in primiparous and multiparous women. It has also been associated with low pH values of umbilical cord blood and with a shorter duration of the first stage of labor in primiparous women. However, it did not affect the rates of 3rd and 4th degree perineal lacerations, episiotomies, advanced neonatal resuscitation, 5-minute Apgar scores and meconium.

CONCLUSION

stimulation with oxytocin should not be used systematically, but only in specific cases. These findings provide further evidence to health professionals and midwives on the use of oxytocin during labor. Under normal conditions, women should be informed of the possible effects of labor stimulation with oxytocin.

Neonatal encephalopathy and the association to asphyxia in labor

OBJECTIVE

In cases with moderate and severe neonatal encephalopathy, we aimed to determine the proportion that was attributable to asphyxia during labor and to investigate the association between cardiotocographic (CTG) patterns and neonatal outcome.

STUDY DESIGN

In a study population of 71,189 births from 2 Swedish university hospitals, 80 cases of neonatal encephalopathy were identified. Cases were categorized by admission CTG patterns (normal or abnormal) and by the presence of asphyxia (cord pH, <7.00; base deficit, ≥12 mmol/L). Cases with normal admission CTG patterns and asphyxia at birth were considered to experience asphyxia related to labor. CTG patterns were assessed for the 2 hours preceding delivery.

RESULTS

Admission CTG patterns were normal in 51 cases (64%) and abnormal in 29 cases (36%). The rate of cases attributable to asphyxia (ie, hypoxic ischemic encephalopathy) was 48 of 80 cases (60%), most of which evolved during labor (43/80 cases; 54%). Both severe neonatal encephalopathy and neonatal death were more frequent with an abnormal, rather than with a normal, admission CTG pattern (13 [45%] vs 11 [22%]; P = .03), and 6 [21%] vs 3 [6%]; P = .04), respectively. Comparison of cases with an abnormal and a normal admission CTG pattern also revealed more frequently observed decreased variability (12 [60%] and 8 [22%], respectively) and more late decelerations (8 [40%] and 1 [3%], respectively).

CONCLUSION

Moderate and severe encephalopathy is attributable to asphyxia in 60% of cases, most of which evolve during labor. An abnormal admission CTG pattern indicates a poorer neonatal outcome and more often is associated with pathologic CTG patterns preceding delivery.

Pharmacological Labor-Stimulating Agents and Neonatal Outcomes

This study examined the physiological and feeding outcomes of term neonates in relation to if they were delivered with pharmacological labor-stimulating agents or not. A retrospective chart review was conducted at a regional hospital. Infant and mother charts were selected from a 6-week timeframe. Descriptive and inferential statistics were used to analyze the 296 charts that were included. There were no statistically significant differences in physiological and feeding parameters of term neonates in relation to pharmacological labor-stimulating agents. The only significant difference found was that deliveries, which received no labor-stimulating agents, had higher rates of meconium staining.

Clinical associations with uterine tachysystole

OBJECTIVES

To determine the incidence of uterine tachysystole (UT) and its association with neonatal depression or metabolic acidemia (DEP).

METHODS

This retrospective study comprised all 6234 women at ≥ 37 weeks' gestation who were monitored during the last 4 hours of tracings before birth in an academic community hospital. DEP was defined by an umbilical artery base deficit value ≥ 10 mmol/L or a 5-minute Apgar ≤ 6 and included 77 births. UT was defined by >15 contractions in 30 minutes.

RESULTS

The overall incidence of UT was 18.3% (1139/6234). In 4.2% (260/6234) UT persisted for >60 min. The rate of UT was similar in births with DEP (14.3%, 11/77) compared to those without DEP (18.3%, 1128/6157; p=0.45). In births with UT, only 1.0% (11/1139) developed DEP. The DEP group had more decelerations at almost every level of contractions and a higher cesarean rate of 49.4% (38/77) compared to 24.0% (1468/6124); p=<0.001 in the group without DEP.

CONCLUSIONS

UT was common, occasionally prolonged and almost always benign. Fetuses with DEP had no more UT than those without DEP. Many babies with DEP declared their vulnerability with decelerations at contraction rates below UT levels and the great majority of them never experienced UT.

High uterine contraction rates in births with normal and abnormal umbilical artery gases

OBJECTIVE

To determine if the incidence of high contraction (HC) rates and associated decelerations were different in term births with metabolic acidemia (MA) compared to those with normal gases (N) over the last 4 h of labor.

METHODS

MA included 316 babies with cord base deficits (BD) over 12 mmol/L N - 3,320 babies with BD under 8 mmol/L. HC rates were defined as >5/10 min.

RESULTS

One or more episodes of HC occurred in 43.7% of MA and 36.6% of N. (p = 0.015) In both groups the HC rates rose from about 1 in 30 patients at the beginning to 1 in 7 to 9 patients at the end. MA showed a different transition of the deceleration response over time. At the beginning the average ratio of decelerations to uterine contractions was similar in both groups but over the final 140 min MA showed a consistently higher ratio.

CONCLUSIONS

Although HC rates were more frequent in the MA, it was not uncommon in N. On average MA showed more decelerations at every level of contractions and had a persistently higher level of decelerations per contraction for more than 2 h before birth.

"Every case of asphyxia can be used as a learning example". Conclusions from an analysis of substandard obstetrical care

AIM

To propose suggestions for improvements in care based on conclusions from studies on low Apgar scores and substandard care during labor.

SETTING AND PATIENTS

Studies on infants with low Apgar scores in a general obstetric population 2004-2006 and claims for financial compensation on the behalf of infants, based on the suspicion that substandard care in conjunction with childbirth has caused severe asphyxia or neonatal death in Sweden 1990-2005.

RESULTS

The most common flaws were related to insufficient fetal surveillance, defective interpretation of cardiotocography (CTG) tracings, not acting in a timely fashion on abnormal CTG, and the incautious use of oxytocin. Besides, in half of the infants a suboptimal mode of delivery added further trauma to the already asphyxiated infant. Additionally, resuscitation was unsatisfactory in many of these infants. The most critical flaw was defective compliance with the guidelines concerning ventilation and the early paging of skilled personnel in cases of imminent asphyxia or known complications during labor. In many case reports, the documentation of the neonatal resuscitation was insufficient to enable accurate and reliable evaluation.

CONCLUSIONS

Examples of proposed improvements in care during labor are the introduction of a permanent educational atmosphere with aside time for daily educational rounds and discussion, cooperation around the use of standardized terminology in CTG interpretation, the cautious use of oxytocin, and the routine paging of a pediatrician before birth in cases of complicated delivery or imminent asphyxia. The proposed interventions need to be evaluated in clinical trials in the future.

Oxytocin augmentation during labor: how to implement medical guidelines into clinical practice

OBJECTIVE

To describe an extensive process to implement guidelines for oxytocin use during labor and to report its effects on compliance to clinical practice guidelines after 1 year.

STUDY DESIGN

A multifaceted strategy was developed to involve all obstetric staff and identify possible local barriers to change in advance. The process lasted for more than 1 year.

MAIN OUTCOME MEASURES

To describe the implementation of oxytocin use according to the new guidelines, and to compare management in clinical practice with guideline recommendations from audits performed before and after the project.

RESULTS

Identification of possible barriers to change, academic detailing, audits with feedback, and local opinion leaders were important factors for a successful process. Documentation of the indication for oxytocin use increased from 54% before, to 86% after the completion of the project (P<0.01). The percentage of incidents in which oxytocin augmentation was started before the diagnosis of labor dystocia was reduced from 40% to 11% (P<0.01). Improvement was found in the documentation of cardiotocography (from 5% to 58%, P<0.01) and contraction frequency at the start of the infusion (from 23% to 63%, P<0.01).

CONCLUSIONS

Our multifaceted strategy involved all obstetric staff, lasted for more than a year, and improved management of oxytocin use according to clinical guidelines. Established rules for documentation were used as a check list to monitor oxytocin use. However, audits with feedback need to continue for medical safety, and have been planned to take place every 6 months.

Of parachutes and patient care: a call to action

Obstetric caregivers are plagued with lawsuits alleging negligence for suboptimal outcomes. Some of those claims are unjustified, but many have merit. We are obligated to create systems designed to minimize the potential for errors that harm our patients. A variety of safety initiatives have been shown to improve patient outcomes in several centers in the United States, but it has been difficult to document the expected association between those results and reduced liability premiums. Furthermore, some individuals and institutions have been reluctant to adopt safety tools such as electronic fetal monitoring certification for all staff working on their Labor and Delivery floor, protocols for managing common clinical scenarios, simulation drills for dealing with uncommon dangerous events, and pre-procedure checklists because of the paucity of evidence based data documenting the effectiveness of those approaches. It is time to move forward with these and other safety initiatives in a serious national attempt to eliminate all preventable adverse patient outcomes in our specialty.

Benefits of introducing universal umbilical cord blood gas and lactate analysis into an obstetric unit

BACKGROUND

Current evidence suggests that umbilical arterial pH analysis provides the most sensitive reflection of birth asphyxia. However, there's debate whether umbilical cord blood gas analysis (UC-BGA) should be conducted on some or all deliveries.

AIM

The aim of this study was to evaluate the impact of introducing universal UC-BGA at delivery on perinatal outcome.

METHODS

An observational study of all deliveries > or =20 weeks' gestation at a tertiary obstetric unit between January 2003 and December 2006. Paired UC-BGA was performed on 97% of deliveries (n = 19,646). Univariate and adjusted analysis assessed inter-year UC-BGA differences and the likelihood of metabolic acidosis and nursery admission.

RESULTS

There was a progressive improvement in umbilical artery pH, pO(2), pCO(2), base excess and lactate values in univariate and adjusted analyses (P < 0.001). There was a significant reduction in the newborns with an arterial pH <7.10 (OR = 0.71; 95%CI 0.53-0.95) and lactate >6.1 mmol/L (OR = 0.37; 95%CI 0.30-0.46). Utilising population specific 5th and 95th percentiles, there was a reduction in newborns with arterial pH less than 5th percentile (pH 7.12; OR = 0.75; 95%CI 0.59-0.96) and lactate levels greater than 95th percentile (6.7 mmol/L; OR = 0.37; 95%CI 0.29-0.49). There was a reduction in term (OR = 0.65; 95%CI 0.54-0.78), and overall (OR = 0.75; 95%CI 0.64-0.87) nursery admissions. These improved perinatal outcomes were independent of intervention rates.

CONCLUSIONS

These data suggest that introduction of universal UC-BGA may result in improved perinatal outcomes, which were observed to be independent of obstetric intervention. We suggest that these improvements might be attributed to provision of biochemical data relating to fetal acid-base status at delivery influencing intrapartum care in subsequent cases.

Obstetric aspects of hypoxic ischemic encephalopathy

Hypoxic ischemic encephalopathy (HIE) describes neonatal encephalopathy that is caused by intrapartum asphyxia and it can result in the long term sequelae of cerebral palsy which is a major cause of disability. The incidence of cerebral palsy has not changed over the last few decades and the challenge to obstetricians remains how best to recognise those babies at risk of this intrapartum insult both before and during labour. Many associations and risk factors are unavoidable or unrecognisable, and others are fairly common and associated with poor predictive value. Intrapartum fetal heart monitoring remains the main focus of attention but how this is best achieved is still the subject of research. Computerised decision support systems built into fetal heart rate monitoring and non-invasive fetal ECG signal pick-up are currently being explored.