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

The Risk of Neonatal Morbidity in Umbilical Artery Hypercarbia and Respiratory Acidosis

OBJECTIVE

 To test the hypothesis that elevated umbilical artery (UA) partial pressure of carbon dioxide (pCO2) is associated with neonatal morbidity and to compare the risk of neonatal morbidity with different patterns of UA acidosis.

STUDY DESIGN

 This was a secondary analysis of a prospective cohort of term, singleton, nonanomalous deliveries with universal cord gas collection. The primary outcome was composite neonatal morbidity. Multivariable logistic regression was used to determine the relative risk (RR) for neonatal morbidity in patients with and without UA hypercarbia. A receiver operating characteristic curve determined the predictive value of pCO2 for neonatal morbidity. An additional multivariable logistic regression was used to evaluate the risk of neonatal morbidity in different patterns of UA acidosis.

RESULTS

 UA hypercarbia was associated with an increased risk of neonatal morbidity (RR: 2.56, 95% confidence interval [CI]: [2.07, 3.17]). After adjusting for UA acidemia, this association remained significant (adjusted RR: 1.39, 95% CI: [1.05, 1.83]). UA pCO2 was less predictive of neonatal morbidity than UA pH (area under the curve [AUC]: 0.65, 95% CI: [0.62, 0.68] vs. AUC: 0.72, 95% CI: [0.69, 0.75], p < 0.01). The odds ratios for neonatal morbidity for respiratory, mixed, and metabolic acidosis compared with normal cord gases were 1.48 (95% CI: [0.88, 2.49]), 6.41 (95% CI: [3.68, 11.17]), and 7.49 (95% CI: [5.76, 9.72]), respectively, p-trend < 0.01.

CONCLUSION

 UA hypercarbia is an independent predictor of neonatal morbidity, even in the setting of concomitant UA acidemia. UA mixed and metabolic acidosis carry significantly greater risk of neonatal morbidity compared with respiratory acidosis.

KEY POINTS

· UA pCO2 is associated with neonatal morbidity.. · UA respiratory acidosis is the UA cord gas pattern least associated with neonatal morbidity.. · UA pH is a superior predictor of neonatal morbidity compared with UA pCO2..

Umbilical arterial lactate levels after normal vaginal and elective cesarean delivery: The role of a longer active second stage most significant in high levels after vaginal delivery

AIM

To evaluate umbilical arterial lactate concentrations after spontaneous vaginal delivery and after elective Cesarean delivery, and to study the simultaneous effects of maternal and obstetric variables in high lactate levels in vaginally delivered healthy term singletons.

METHODS

The birth register study included information about the umbilical artery lactate values and clinical perinatal data from 7723 women and their singleton newborns (7301 spontaneous vaginal and 422 elective cesareans) from Kuopio University Hospital, Finland. High lactate levels were evaluated more extensively among healthy term neonates (N = 6541), to evaluate high levels after normal vaginal labors.

RESULTS

The mean lactate level was significantly lower after elective cesarean compared to vaginal delivery (2.42 [0.94] vs. 3.56 [1.62] mmol/l; p < 0.0001). Consequently, the 90th percentile limit values were 3.60 and 5.80 mmol/L. Among healthy term newborns born vaginally, higher lactate values (≥5.80 mmol/L) were independently associated with a longer duration of the active second stage of labor (ORs 1.91-10.97) and duration of ruptured fetal membranes (ORs 1.36-2.46), higher gestational age at birth (ORs 1.41-1.86), null parity (OR 2.17), maternal infection (OR 1.81) and short maternal stature (OR 1.45). We report 90th/95th limits for umbilical arterial lactate values in relation to the various durations of labors for term newborns who are delivered by the vaginal route.

CONCLUSIONS

Even though the high umbilical lactate levels may indicate serious birth asphyxia, levels after vaginal birth reflect the physiological stress and subclinical transient asphyxia frequently seen in normal vaginal deliveries.

Effect of maternal oxygen supplementation for parturient undergoing elective cesarean section by high-flow nasal oxygen compared with room air on fetal acidemia: study protocol for a randomized controlled trial

BACKGROUND

Maternal oxygen supplementation is usually used as an intrauterine resuscitation technique to prevent fetal hypoxia and acidemia during delivery. However, there has been a great deal of controversy regarding the effects of prophylactic maternal oxygen during cesarean section, during which the incidence of fetal acidemia seems to be higher compared with that during labor. High-flow nasal oxygen (HFNO) can improve oxygenation better in patients with high-flow oxygen airflow. The purpose of this study is to determine whether maternal oxygen supplementation with HFNO has a positive effect on fetal acidemia during cesarean section through umbilical arterial blood gas analysis.

METHOD

This prospective, single-center, randomized, double-blinded trial will enroll 120 patients undergoing cesarean section. Participants will be randomly assigned to the HFNO group or air group at a 1:1 ratio. For parturients in the HFNO group, the flow rate is 40L/min, and the oxygen is heated to 37℃ with humidity 100% oxygen concentration through the Optiflow high-flow nasal oxygen system. And for the air group, the flow rate is 2 L/min with an air pattern through the same device. The primary outcome was umbilical artery (UA) lactate. Secondary outcomes include UA pH, PO2, PCO2, BE, the incidence of pH < 7.20 and pH < 7.10, Apgar scores at 1 and 5 min, and neonatal adverse outcomes.

DISCUSSION

Our study is the first trial investigating whether maternal oxygen supplementation with HFNO can reduce the umbilical artery lactate levels and the incidence of fetal acidemia in cesarean section under combined spinal-epidural anesthesia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05921955. Registered on 27 June 2023.

Influence of umbilical cord pH on the outcome of hearing screening with otoacoustic emissions in healthy newborns

The effect of hypoxia on the functioning of the outer hair cells of the cochlea, which are responsible for the response to otoemissions used in neonatal hearing screening, is well known. The aim of this study is to determine the influence of mild to moderate variations in umbilical cord pH at birth on the outcome of hearing screening with otoemissions in healthy newborns without hearing risk factors. The sample is composed of 4536 healthy infants. The results show no significant differences in the hearing screening outcome between the asphyctic (<7.20) and normal pH group. Nor is a figure below 7.20 detected in the sample that is related to an alteration in the screening. When broken down into subgroups with known factors of variation in the screening result, such as gender or lactation, no significant differences in response were detected. Apgar ≤7 is significantly related to pH<7.20. In conclusion, mild-moderate asphyxia associated with delivery of healthy newborns, without auditory risk factors, does not alter the outcome of otoemission screening.

Long-term neurodevelopmental effects of exclusively high cord lactate levels in term newborn

INTRODUCTION

Cord arterial blood gas analysis (ABGA) results are used as diagnostic criteria for hypoxic-ischemic encephalopathy in newborns with suspected perinatal asphyxia. This study evaluated the effect of cord ABGA lactate level on the long-term neurodevelopment of newborns without any clinical signs of perinatal asphyxia.

METHODS

This clinical observation study was designed among term babies born between 2018 and 2019 in our unit. Cases with a 5-min Apgar score <7 and signs of fetal distress in their antenatal follow-up were excluded. The cases (n = 1438) were divided into two groups those with high cord lactate levels (above 5 mmol/L, n = 92) and those with low lactate levels (below 2 mmol/L, n = 255). An Ages and Stages Questionnaire, Third Edition (ASQ-3) developmental screening questionnaire was sent to all parents. Patients with a chronological age between 24 and 42 months and for whom the parents fulfilled the questionnaire (low lactate group, n = 29, and high lactate group, n = 45) were evaluated.

RESULTS

No difference was observed between the two groups in terms of demographic characteristics such as age (p = .1669), male gender (p = .906), mother's working situation (p = .948), mother's education level (p = .828), father's education level (p = .507), and family's total income (p = .642). Mean ACQ-3 developmental screening test scores were significantly lower in the high lactate group compared to the low lactate group concerning; fine motor (40 vs. 60, p = .001), problem-solving (50 vs. 60, p = .002), and personal social development (45 vs. 60, p = .003). No difference was observed in terms of communication and gross motor total scores.

DISCUSSION

In general practice, routine cord ABGA is not generally recommended for patients with normal Apgar scores and no suspected hypoxia. However, in this study, we observed that cases with a normal 5-min Apgar score, no suspected perinatal asphyxia, and a cord lactate value of ≥5 fell behind their peers when evaluated with the ACQ-3 developmental screening questionnaire.

Umbilical cord gas analysis: clinical implications of a comprehensive, contemporary determination of normal ranges

BACKGROUND

Umbilical cord gases are often used to assess the impact of labor and delivery on the fetus. However, no large series exists that reflects contemporary obstetrical practice or that analyzed blood gas ranges by route of delivery. Baseline, prelabor acid-base status in the human fetus is also poorly defined, rendering the assessment of blood gas changes during labor difficult.

OBJECTIVE

This study aimed to define normal umbilical cord gas and lactate values, stratified by mode of delivery, in a large contemporary series in which universal umbilical cord gas evaluation was dictated by protocol.

STUDY DESIGN

This was a retrospective cohort study. We analyzed the umbilical cord gas and lactate data of an unselected population of infants born between March 2012 and April 2022 at a large teaching hospital. These values were then analyzed by mode of delivery and, for cesarean deliveries, by indication for cesarean delivery and type of anesthesia. Umbilical cord gas values from infants delivered by elective cesarean delivey under general anesthesia without labor were considered representative of baseline, prelabor values.

RESULTS

Data were available for 45,475 infants. The median arterial pH values and interquartile ranges for vaginal births, elective cesarean deliveries without labor, and cesarean deliveries performed for fetal heart rate concerns were 7.27 (0.09), 7.27 (0.06), and 7.25 (0.09), respectively. Arterial lactate values for these same 3 groups were 4.1 (2.5), 2.5 (1.2), and 4.0 (2.8) mmoles/L, respectively. Because of the very large sample size, most comparisons yielded differences that were statistically significant, but clinically irrelevant. Of all the infants, 14% had an arterial pH <7.20; a pH value of 7.1 represents 2 standard deviations from the mean.

CONCLUSION

This large, population-based study of umbilical cord gas and lactate levels in an unselected population, stratified by delivery mode, represents a previously unavailable benchmark for the evaluation of umbilical cord gases. Arterial umbilical cord pH values for infants delivered by elective caesarean delivery without labor (median pH 7.28) reflect a lower prelabor fetal pH baseline than previously assumed. This finding, coupled with our determination that a 2 standard deviation below normal pH limit of 7.1, instead of the historic arbitrary pH of 7.2 threshold, helps to explain the poor positive predictive value of electronic fetal heart rate monitoring, a test designed to detect arterial pH levels that have fallen from an assumed baseline near pH 7.4 to an assumed potentially injurious pH level of <7.2. Uncomplicated labor, even when prolonged, does not generally lead to a clinically significant cumulative hypoxic stress to the human fetus. These findings, along with our determination that there is no difference in the acid-base status among infants delivered by cesarean delivery for fetal heart rate concerns, help to explain the failure of current approaches in labor and delivery management to reduce the rates of neonatal hypoxic-ischemic encephalopathy and cerebral palsy, conditions that almost always reflect developmental events rather than the effects of labor on the fetus.

Correlations of Placental Histopathology, Neonatal Outcome, and Cardiotocogram Baseline Variability and Acceleration Patterns in the Growth Restricted Preterm Population

OBJECTIVE

To evaluate the possible connections of cardiotocography (CTG) signs with neonatal outcome and placental histopathology between growth restricted preterms.

MATERIALS AND METHODS

Placental slides, baseline variability, and acceleration patterns of cardiotocograms, and neonatal parameters were studied retrospectively. Placental histopathological changes were diagnosed according to the Amsterdam criteria; percentage of intact terminal villi and capillarization of villi were also studied. 50 cases were analyzed: 24 were early-onset fetal growth restriction (FGR), 26 were late-onset FGR.

RESULTS

Reduced baseline variability was related to poor neonatal outcome; lack of accelerations similarly had associations with poor outcomes. Maternal vascular malperfusion, avascular villi, VUE, and chorangiosis were more common in the background of reduced baseline variability and absence of accelerations. Lower percentage of intact terminal villi was significantly associated with lower umbilical artery pH, higher lactate levels, and reduced baseline variability on CTG; absence of accelerations was correlated with decreased capillarization of terminal villi.

CONCLUSIONS

Baseline variability and absence of accelerations seem to be useful and reliable markers in predicting poor neonatal outcome. Maternal and fetal vascular malperfusion signs, decreased capillarization, and lower percentage of intact villi in placenta could contribute to pathologic CTG signs and poor prognosis.

The effect of intrapartum prolonged oxygen exposure on fetal metabolic status: secondary analysis from a randomized controlled trial

Objective

The aim of the study is to assess the effect of maternal prolonged oxygen exposure during labor on fetal acid-base status, fetal heart rate tracings, and umbilical cord arterial metabolites.

Design

The study was conducted as a secondary analysis.

Settings

The study was set in three tertiary teaching hospitals in Beijing, China.

Participants

Approximately 140 women in the latent phase of labor with no complications participated in the study.

Intervention

Participants were randomly allocated in a 1:1 ratio to receive either 10 L of oxygen per minute in a tight-fitting simple facemask until delivery or room air only.

Main outcome measures

The primary outcome was the umbilical cord arterial lactate.

Results

Baseline demographics and labor outcomes were similar between the oxygen and room air groups; the time from randomization to delivery was 322 ± 147 min. There were no differences between the two groups in the umbilical cord arterial lactate (mean difference 0.3 mmol/L, 95% confidence interval -0.2 to 0.9), the number of participants with high-risk category II fetal heart rate tracings (relative risk 0.94, 95% confidence interval 0.68 to 1.32), or the duration of those high-risk tracings (mean difference 3.6 min, 95% confidence interval -9.3 to 16.4). Prolonged oxygen exposure significantly altered 91 umbilical cord arterial metabolites, and these alterations did not appear to be related to oxidative stress.

Conclusion

Maternal prolonged oxygen exposure during labor did not affect either the umbilical cord arterial lactate or high-risk category II fetal heart rate tracings but might result in alterations to the umbilical cord arterial metabolic profile.

Clinical trial registration

www.clinicaltrials.gov, identifier NCT03764696.

Neonatal Hemodynamic Characteristics of the Recipient Twin of Twin-To-Twin Transfusion Syndrome Not Treated with Fetoscopic Laser Surgery

Background: This paper’s intent is to describe the neonatal hemodynamic characteristics of recipient twins of monochorionic pregnancies complicated with twin-to-twin transfusion syndrome (TTTS), born without prenatal fetoscopic selective laser coagulation (FSLC). Methods: Retrospective analysis of hemodynamic characteristics was performed during the first five days of life of recipient twins from untreated TTTS. Results: Forty-two recipient twins were included and divided into three groups: no hemodynamic impairment (NoHI) (n = 15, 36%), isolated high blood pressure (HighBP) (n = 12, 28%), and cardiac failure group (CF) (n = 15, 36%). Patients of both CF and HighBP groups had high systolic blood pressure during the first 12 h of life and ventricular hypertrophy at early echocardiography. Cardiac failure occurred at a median age of 14 h (IQR = 6−24) and was followed by a drop in systolic and diastolic blood pressure. Acute kidney injury was more frequent (93% vs. 25%, p < 0.001) and severe (p <0.001) in the CF group than in the HighBP group. The mortality rate in the CF group was 40%. Factors associated with CF were twin anemia-polycythemia sequence (p = 0.012), very preterm birth (p = 0.040), and polycythemia (p = 0.002). Conclusion: One-third of recipient twins born without prenatal FSLC developed life-threatening cardiac failure during the first 24 h of life.

Improved maternal-fetal outcomes among emergency obstetric referrals following phone call communication at a teaching hospital in south western Uganda: a quasi-experimental study

BACKGROUND

Emergency obstetric referrals develop adverse maternal-fetal outcomes partly due to delays in offering appropriate care at referral hospitals especially in resource limited settings. Referral hospitals do not get prior communication of incoming referrals leading to inadequate preparedness and delays of care. Phone based innovations may bridge such communication challenges. We investigated effect of a phone call communication prior to referral of mothers in labour as intervention to reduce preparation delays and improve maternal-fetal outcome at a referral hospital in a resource limited setting.

METHODS

This was a quasi-experimental study with non-equivalent control group conducted at Mbarara Regional Referral Hospital (MRRH) in South Western Uganda from September 2020 to March 2021. Adverse maternal-fetal outcomes included: early neonatal death, fresh still birth, obstructed labour, ruptured uterus, maternal sepsis, low Apgar score, admission to neonatal ICU and hysterectomy. Exposure variable for intervention group was a phone call prior maternal referral from a lower health facility. We compared distribution of clinical characteristics and adverse maternal-fetal outcomes between intervention and control groups using Chi square or Fisher's exact test. We performed logistic regression to assess association between independent variables and adverse maternal-fetal outcomes.

RESULTS

We enrolled 177 participants: 75 in intervention group and 102 in control group. Participants had similar demographic characteristics. Three quarters (75.0%) of participants in control group delayed on admission waiting bench of MRRH compared to (40.0%) in intervention group [p =  < 0.001]. There were significantly more adverse maternal-fetal outcomes in control group than intervention group (obstructed labour [p = 0.026], low Apgar score [p = 0.013] and admission to neonatal high dependency unit [p =  < 0.001]). The phone call intervention was protective against adverse maternal-fetal outcome [aOR = 0.22; 95%CI: 0.09-0.44, p = 0.001].

CONCLUSION

The phone call intervention resulted in reduced delay to patient admission at a tertiary referral hospital in a resource limited setting, and is protective against adverse maternal-fetal outcomes. Incorporating the phone call communication intervention in the routine practice of emergency obstetric referrals from lower health facilities to regional referral hospitals may reduce both maternal and fetal morbidities.

TRIAL REGISTRATION

Pan African Clinical Trial Registry PACTR20200686885039.

Comparative study of dinoprostone and misoprostol for induction of labor in patients with premature rupture of membranes after 35 weeks

The modalities of induction of labor in the event of premature rupture of membranes are controversial. The main purpose of this study was to compare the modalities of delivery after the use of dinoprostone or misoprostol for labor induction in the preterm rupture of membranes after 35 weeks in women with an unfavorable cervix. We then studied maternal and fetal morbidity for the two drugs. Retrospective, single-center, comparative cohort study in a level 3 maternity unit in France from 2009 to 2018 comparing vaginal administration of misoprostol 50 µg every six hours (maximum 150 µg) and administration of dinoprostone 10 mg, a slow-release vaginal insert, for 24 h (maximum 20 mg), for labor induction in the preterm rupture of membranes after 35 weeks in women with an unfavorable cervix (Bishop score < 6). We included 904 patients, 656 in the misoprostol group and 248 in the dinoprostone group. Vaginal delivery rate was significantly higher in the dinoprostone group (89% vs. 82%, p = 0.016). There were more cesarean sections for abnormal fetal heart rate in the misoprostol group (p = 0.005). The time interval from induction to the beginning of the active phase of labor and the duration of labor were shorter in the misoprostol group than in the dinoprostone group (437 min vs. 719 min, p < 0.001 and 335 min vs. 381 min, p = 0.0023, respectively). Maternal and neonatal outcomes were not significantly different in the two groups. Vaginal dinoprostone used for labor induction in preterm rupture of membranes seems to be more effective for vaginal delivery than vaginal misoprostol (50 µg).

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.

Association of umbilical cord blood gas values with mortality and severe neurologic injury in preterm neonates <29 weeks' gestation: a national cohort study

BACKGROUND

Umbilical cord arterial and venous blood gas values reflect the acid-base balance status of a newborn at birth. Derangement in these values has been linked to poor neonatal outcomes in term and late preterm neonates; however, the utility of these values in preterm neonates of <29 weeks' gestation is unclear.

OBJECTIVE

This study aimed to determine the associations of umbilical cord arterial and venous blood gas values with neonatal mortality and severe neurologic injury in extremely preterm neonates and to identify the cutoff values associated with 2.5-fold increases or decreases in the posttest probabilities of outcomes.

STUDY DESIGN

This was a retrospective cohort study of neonates who were born at 23+0 to 28+6 weeks' gestation between January 1, 2018 and December 31, 2019, and who were admitted to neonatal units in Canada.

EXPOSURE

Various cut-offs of umbilical cord blood gas values and lactate values were studied.

MAIN OUTCOMES AND MEASURES

The main outcomes were mortality before discharge from the neonatal unit and severe neurologic injury defined as grade 3 or 4 periventricular or intraventricular hemorrhage or periventricular leukomalacia. The outcome rates were calculated for various cutoff values of umbilical cord blood gas parameters and were adjusted for birthweight, gestational age, sex, and multiple births. Likelihood ratios were calculated to derive posttest probabilities.

RESULTS

A total of 1040 and 1217 neonates had analyzable umbilical cord arterial and venous blood gas values, respectively. In the cohort, the mean (standard deviation) gestational age was 26.5 (1.5) weeks, the mean birthweight was 936 (215) g, the prevalence of mortality was 10% (105/1040), and the prevalence of severe neurologic injury was 9% (92/1016). An umbilical cord arterial pH of ≤7.1 and base excess of ≤-12 mmol/L were associated with >2.5-fold higher posttest probability of mortality, and an umbilical cord arterial or venous lactate value of <3 was associated with a 2.5-fold lower posttest probability of mortality. An umbilical cord arterial base excess of <-16 mmol/L was associated with a higher posttest probability of severe neurologic injury, whereas a lactate value of <3 was associated with a lower posttest probability.

CONCLUSION

In preterm neonates of <29 weeks' gestation, low umbilical cord arterial pH and high umbilical cord arterial base excess values were associated with a clinically important increase in the posttest probability of mortality, whereas low umbilical cord arterial or venous lactate values were associated with a decrease in the posttest probability of mortality.

Action leveraging evidence to reduce perinatal mortality and morbidity (ALERT): study protocol for a stepped-wedge cluster-randomised trial in Benin, Malawi, Tanzania and Uganda

Background

Insufficient reductions in maternal and neonatal deaths and stillbirths in the past decade are a deterrence to achieving the Sustainable Development Goal 3. The majority of deaths occur during the intrapartum and immediate postnatal period. Overcoming the knowledge-do-gap to ensure implementation of known evidence-based interventions during this period has the potential to avert at least 2.5 million deaths in mothers and their offspring annually. This paper describes a study protocol for implementing and evaluating a multi-faceted health care system intervention to strengthen the implementation of evidence-based interventions and responsive care during this crucial period.

Methods

This is a cluster randomised stepped-wedge trial with a nested realist process evaluation across 16 hospitals in Benin, Malawi, Tanzania and Uganda. The ALERT intervention will include four main components: i) end-user participation through narratives of women, families and midwifery providers to ensure co-design of the intervention; ii) competency-based training; iii) quality improvement supported by data from a clinical perinatal e-registry and iv) empowerment and leadership mentoring of maternity unit leaders complemented by district based bi-annual coordination and accountability meetings. The trial’s primary outcome is in-facility perinatal (stillbirths and early neonatal) mortality, in which we expect a 25% reduction. A perinatal e-registry will be implemented to monitor the trial. Our nested realist process evaluation will help to understand what works, for whom, and under which conditions. We will apply a gender lens to explore constraints to the provision of evidence-based care by health workers providing maternity services. An economic evaluation will assess the scalability and cost-effectiveness of ALERT intervention.

Discussion

There is evidence that each of the ALERT intervention components improves health providers’ practices and has modest to moderate effects. We aim to test if the innovative packaging, including addressing specific health systems constraints in these settings, will have a synergistic effect and produce more considerable perinatal mortality reductions.

Trial registration

Pan African Clinical Trial Registry (www.pactr.org): PACTR202006793783148. Registered on 17th June 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07155-z.

Point-of-care assessment of combined umbilical arterial and venous lactate: A potential screening test for neonatal acidosis

OBJECTIVE

To examine the relationship between point-of-care (POC) measurement of combined umbilical arterial and venous (CUAV) lactate and umbilical artery (UA) lactate to determine whether POC assessment of this sample could be an alternative screening modality for neonatal acidosis and aid prediction of neonatal morbidity.

METHODS

In this cross-sectional pilot study, UA and CUAV cord blood samples were collected from live, singleton neonates delivered between June and August 2019, at a tertiary care center. UA samples were analyzed for pH and lactate using a blood gas analyzer. CUAV lactate was also assessed on a blood gas analyzer and at the POC. Linear regression was used to determine the correlation between these samples.

RESULTS

A total of 152 neonates were included. There was a statistically significant correlation between CUAV lactate concentrations and UA lactate concentrations (R²  = 0.744). Additionally, CUAV lactate concentration measured at the POC was significantly correlated with that measured on a traditional blood gas analyzer (R²  = 0.928).

CONCLUSION

POC testing of CUAV lactate is reliable and closely correlated with UA lactate concentrations, making POC testing of CUAV lactate a potential screening test for neonatal acidosis. More data are needed to establish standardization of this test relative to its predictive value in clinical neonatal outcomes.

Medico-legal considerations in the context of neonatal encephalopathy and therapeutic hypothermia

Neonatal encephalopathy (NE) is a significant complication of the peripartum period. It can lead to lifelong neurologic disabilities, including cerebral palsy, cognitive impairments, developmental delays, and epilepsy. Induced hypothermia is the first therapy, which has shown promise in improving the outcomes for neonates with moderate to severe NE following a presumed intrapartum insult. NE is also a frequent source of medical malpractice litigation. In this paper, we will review salient features of the American Tort System as it pertains to medical malpractice. We will discuss the obstetric medico-legal implications of therapeutic hypothermia and suggest a five-step approach to analyzing neonatal cases for causation, etiology, timing of occurrence, responsibility, and liability. We will close with three illustrative clinical cases.

Incidence and determinants of perinatal mortality among women with obstructed labour in eastern Uganda: a prospective cohort study

BACKGROUND

In Uganda, the incidence and determinants of perinatal death in obstructed labour are not well documented. We determined the incidence and determinants of perinatal mortality among women with obstructed labour in Eastern Uganda.

METHODS

Between July 2018 and September 2019, 584 with obstructed labour were recruited and followed up to the 7th day postnatal. Information on maternal characteristics, obstetric factors and laboratory parameters was collected. Each patient received the standard perioperative care. We used a generalized linear model for the Poisson family, with a log link and robust variance estimation to determine the association between the exposure variables and perinatal death.

RESULTS

Of the 623 women diagnosed with obstructed labour, 584 met the eligibility criteria. There were 24 fresh still births (FSB) and 32 early neonatal deaths (ENND) giving an FSB rate of 43.8 (95% CI 28.3-64.4) deaths per 1000 total births; early neonatal death rate of 58.4 (95% CI 40.3-81.4) deaths per 1000 and an overall perinatal mortality rate of 102.2 (95% CI 79.4-130.6) deaths in the first 7 days of life. A mother being referred in active labour adjusted risk ratio of 2.84 (95% CI: 1.35-5.96) and having high blood lactate levels at recruitment adjusted risk ratio 2.71 (95% CI: 1.26-4.24) were the determinants of perinatal deaths.

CONCLUSIONS

The incidence of perinatal death was four times the regional and national average. Babies to women referred in active labour and those with high maternal blood lactate were more likely to die.

Reference Values for Umbilical Artery Lactate by Mode of Delivery and Gestational Age: A Retrospective Observational Study

INTRODUCTION

Umbilical artery cord blood provides information about the intrauterine metabolism during labor. Umbilical artery lactate is a useful parameter in predicting neonatal morbidity, but data on normal values are limited. We aimed to provide reference ranges of umbilical artery lactate values across the combination of gestational age and mode of delivery.

METHODS

A single-center retrospective observational study of liveborn infants born between 23 and 42 completed weeks gestation was conducted. Lactate, base deficit (BD), and pH from arterial cord blood were assessed between June 2018 and November 2020 and compared across gestational ages and modes of delivery.

RESULTS

Overall, there were 3,353 infants with evaluable data. Lactate values at the 50th, 90th, and 97th percentile were 3.4, 7.0, and 9.0 mmol/L. Lactate was inversely correlated with pH (r = -0.77, p < 0.001) and positively correlated with BD (r = 0.63, p < 0.001). Lactate values changed significantly across gestational age (Kruskal-Wallis test, p < 0.001) which was attributable to an increase in lactate at 39-41 weeks gestational age. Also, lactate values were different across modes of delivery (Kruskal-Wallis test, p < 0.001) with lowest values in elective CS and highest values in vaginal instrumental deliveries. Comprehensive reference ranges across modes of delivery and gestational ages could be established.

DISCUSSION

Mode of delivery and gestational age contribute to lactate levels with highest values occurring in vaginal instrumental deliveries and between 39 and 41 weeks gestational age. Based on these observations, we provide detailed reference ranges for clinical use.

Daidzein supplementation enhances embryo survival by improving hormones, antioxidant capacity, and metabolic profiles of amniotic fluid in sows

Daidzein (DAI) is a kind of natural isoflavonic phytoestrogen with estrogenic activity. However, little is known about its influence on early fetal growth in mammalian animals. The current study aimed to explore the characteristics of amniotic fluid exposure to dietary DAI using ¹H NMR-based metabolomics and biochemical analysis. Here, we found that DAI supplementation at a dose of 200 mg kg^-1 significantly enhanced the number of viable embryos at the early gestation stage (P < 0.05). DAI significantly elevated the concentrations of estrogen (E) and insulin-like growth factor-I (IGF-I) in the amniotic fluid (P < 0.05). Moreover, DAI tended to increase the concentration of progesterone, but decrease the concentration of tumor necrosis factor α (TNF-α) in the amniotic fluid (0.05 < P < 0.10). Interestingly, the activity of glutathione peroxidase (GSH-Px) was higher in the DAI group than in the CON group (P < 0.05). An ¹H NMR-based metabolomics analysis identified and quantified more than 30 compounds in the amniotic fluid, and some critical metabolites such as arginine, creatine, and citrate were found to be significantly elevated upon DAI supplementation (P < 0.05). Importantly, the metabolic pathways involved in arginine and proline metabolisms were found to be significantly affected by DAI. Collectively, dietary DAI may improve embryo survival by improving hormones, antioxidant capacity, and metabolic profiles in the maternal amniotic fluid.

The effects of labor on airway outcomes with Supreme™ laryngeal mask in women undergoing cesarean delivery under general anesthesia: a cohort study

BACKGROUND

Pregnancy is associated with higher incidence of failed endotracheal intubation and is exacerbated by labor. However, the influence of labor on airway outcomes with laryngeal mask airway (LMA) for cesarean delivery is unknown.

METHODS

This is a secondary analysis of a prospective cohort study on LMA use during cesarean delivery. Healthy parturients who fasted > 4 h undergoing Category 2 or 3 cesarean delivery with Supreme™ LMA (sLMA) under general anesthesia were included. We excluded parturients with BMI > 35 kg/m2, gastroesophageal reflux disease, or potentially difficult airway (Mallampati score of 4, upper respiratory tract or neck pathology). Anesthesia and airway management reflected clinical standard at the study center. After rapid sequence induction and cricoid pressure, sLMA was inserted as per manufacturer's recommendations. Our primary outcome was time to effective ventilation (time from when sLMA was picked up until appearance of end-tidal carbon dioxide capnography), and secondary outcomes include first-attempt insertion failure, oxygen saturation, ventilation parameters, mucosal trauma, pulmonary aspiration, and Apgar scores. Differences between labor status were tested using Student's t-test, Mann-Whitney U test, or Fisher's exact test, as appropriate. Quantitative associations between labor status and outcomes were determined using univariate logistic regression analysis.

RESULTS

Data from 584 parturients were analyzed, with 37.8% in labor. Labor did not significantly affect time to effective ventilation (mean (SD) for labor: 16.0 (5.75) seconds; no labor: 15.3 (3.35); mean difference: -0.65 (95%CI: - 1.49 to 0.18); p = 0.1262). However, labor was associated with increased first-attempt insertion failure and blood on sLMA surface. No reduction in oxygen saturation or pulmonary aspiration was noted.

CONCLUSIONS

Although no significant increase in time to effective ventilation was noted, labor may increase the number of insertion attempts and oropharyngeal trauma with sLMA use for cesarean delivery in parturients at low risk of difficult airway. Future studies should investigate the effects of labor on LMA use in high risk parturients.

TRIAL REGISTRATION

The study was prospectively registered at clinicaltrials.gov ( NCT02026882 ) on 3 January 2014.

Maternal and fetal cardiovascular and metabolic effects of intra-operative uterine handling under general anesthesia during pregnancy in sheep

A cohort study of 6,500,000 human pregnancies showed an increased risk of adverse fetal outcomes following abdominal but not non-abdominal surgery under general anesthesia. This may be the consequence of uterine handling during abdominal surgery. However, there are no data on any effects on the cardiometabolic physiology of the fetus or mother in response to uterine manipulation in otherwise healthy pregnancy. Consequently, 9 sheep in late gestation were anesthetized with isofluorane and maternal and fetal catheters and flow probes were implanted to determine cardiovascular and metabolic changes during uterine handling. Uterine handling led to an acute increase in uterine artery vascular resistance, fetal peripheral vasoconstriction, a reduction in oxygen delivery to the femoral circulation, worsening fetal acidosis. There was no evidence of systemic fetal hypoxia, or changes in fetal heart rate, carotid blood flow or carotid oxygen delivery. Therefore, the data support that uterine handling during abdominal surgery under general anesthesia can impact adversely on fetal cardiometabolic health. This may provide a potential explanation linking adverse fetal outcomes in abdominal compared with non-abdominal surgery during pregnancy. The data have important implications for human fetal surgery where the uterus is handled, as operative procedures during late gestation under general maternal anesthesia become more prevalent.

Epidural analgesia during birth and adverse neonatal outcomes: A population-based cohort study

BACKGROUND

In general, epidural analgesia is considered a safe and efficient way to relieve pain during active labour and is increasingly used in childbirth. It is well documented that epidural analgesia during birth has benefits but also adverse effects. However, evidence is limited on how epidural analgesia influences neonatal outcome in a low-risk population of birthing women.

AIM

To examine low Apgar score, foetal hypoxia and admission to the neonatal intensive care unit in neonates of low-risk women receiving epidural analgesia during birth.

METHODS

A cohort study using registry data to investigate a population of 23,272 low-risk women giving birth at a university hospital.

RESULTS

Epidural analgesia was used in 21.6% of low-risk women during birth. Low Apgar score, foetal hypoxia, and admission to the neonatal intensive care unit were found in 0.6%, 0.6%, and 10.0%, respectively in neonates of mothers receiving epidural analgesia during birth compared to 0.3%, 0.6%, and 5.6%, respectively in the non-exposed group. Epidural analgesia was associated with low Apgar score, adjusted odds ratio 1.76 (95% CI 1.07-2.90) and admission to the neonatal intensive care unit, adjusted odds ratio 1.43 (95% CI 1.26-1.62). A mediation analysis indicates the impact of epidural analgesia on adverse neonatal outcomes was mediated by obstetric complications like maternal fever, labour augmentation, and foetal malpresentation.

CONCLUSION

This study found use of epidural analgesia during birth in low-risk pregnant women was associated with infant low Apgar score and admission to the neonatal intensive care unit.

Umbilical cord arterial and venous gases, ionogram, and glucose level for predicting neonatal morbidity at term

OBJECTIVE

To determine which parameter of umbilical arterial cord gas analysis, pH, base deficit, lactate concentration, ionogram values, or glucose level index is the best predictor of neonatal morbidity at term.

DESIGN

We conducted a 15-month retrospective cohort study that included all nonanomalous, singleton, term births at a single center. The predictive ability of lactate concentration, base deficit, pH, ionogram values, and glucose level were compared using receiver-operating characteristic curves for global and neurological composite morbidity. Optimal cutoff values for lactate concentration, base deficit, and pH were estimated based on their maximum area under the curve.

RESULTS

We included 5161 newborns: 52 (1.01 %) had global composite morbidity, and 17 had (0.33 %) neurological composite morbidity. Blood levels of potassium, calcium, natremia, glucose level, and HCO₃^- did not differ significantly between groups. pH, partial pressure of CO₂, partial pressure of O₂, base deficit, and lactate levels differed significantly between neonates in the groups with and without global composite morbidity. Nearly similar results were found for neurological composite morbidity. The predictive ability did not differ between arterial pH and arterial lactate concentration (P = .25) and base deficit (P = .79). Optimal cutoff values to predict global composite morbidity were arterial pH 7.144, venous pH 7.236, and arterial lactate concentration 6.5 mmol/L.

CONCLUSIONS

Acid-base status analysis remains the best objective indicator for predicting neonatal morbidity and can be estimated using pH, lactate, or base deficit. Ionogram cord blood composition and glucose level do not appear to be useful for this purpose.

Circulating mRNAs are differentially expressed in pregnancies with severe placental insufficiency and at high risk of stillbirth

BACKGROUND

Fetuses affected by placental insufficiency do not receive adequate nutrients and oxygenation, become growth restricted and acidemic, and can demise. Preterm fetal growth restriction is a severe form of placental insufficiency with a high risk of stillbirth. We set out to identify maternal circulating mRNA transcripts that are differentially expressed in preterm pregnancies complicated by very severe placental insufficiency, in utero fetal acidemia, and are at very high risk of stillbirth.

METHODS

We performed a cohort study across six hospitals in Australia and New Zealand, prospectively collecting blood from 128 pregnancies complicated by preterm fetal growth restriction (delivery < 34 weeks' gestation) and 42 controls. RNA-sequencing was done on all samples to discover circulating mRNAs associated with preterm fetal growth restriction and fetal acidemia in utero. We used RT-PCR to validate the associations between five lead candidate biomarkers of placental insufficiency in an independent cohort from Europe (46 with preterm fetal growth restriction) and in a third cohort of pregnancies ending in stillbirth.

RESULTS

In the Australia and New Zealand cohort, we identified five mRNAs that were highly differentially expressed among pregnancies with preterm fetal growth restriction: NR4A2, EMP1, PGM5, SKIL, and UGT2B1. Combining three yielded an area under the receiver operative curve (AUC) of 0.95. Circulating NR4A2 and RCBTB2 in the maternal blood were dysregulated in the presence of fetal acidemia in utero. We validated the association between preterm fetal growth restriction and circulating EMP1, NR4A2, and PGM5 mRNA in a cohort from Europe. Combining EMP1 and PGM5 identified fetal growth restriction with an AUC of 0.92. Several of these genes were differentially expressed in the presence of ultrasound parameters that reflect placental insufficiency. Circulating NR4A2, EMP1, and RCBTB2 mRNA were differentially regulated in another cohort destined for stillbirth, compared to ongoing pregnancies. EMP1 mRNA appeared to have the most consistent association with placental insufficiency in all cohorts.

CONCLUSIONS

Measuring circulating mRNA offers potential as a test to identify pregnancies with severe placental insufficiency and at very high risk of stillbirth. Circulating mRNA EMP1 may be promising as a biomarker of severe placental insufficiency.

A before and after study of the impact on obstetric and perinatal outcomes following the introduction of an educational package of fetal heart rate monitoring education coupled with umbilical artery lactate sampling in a low resource setting labor ward in South Africa

Introduction

Rates of cesarean section (CS) are increasing and abnormal fetal heart rate tracing and concern about consequent acidosis remain one of the most common indications for primary CS. Umbilical artery (UA) lactate sampling provides clinicians with point of care feedback on CTG interpretation and intrapartum care and may result in altered future practice.

Materials and methods

From 3rd March - 12th November 2014 we undertook a before and after study in Pretoria, South Africa, to determine the impact of introducing a clinical package of fetal heart rate monitoring education and prompt feedback with UA cord lactate sampling, using a hand-held meter, on maternal and perinatal outcomes.

Results

Nine hundred thirty-six consecutive samples were analyzed (pre n = 374 and post n = 562). There was no difference in mean lactate (4.6 mmol/L [95%CI 4.4–4.8] compared with 4.9 mmol/L [95%CI 4.7–5.1], p = 0.089). Suspected fetal compromise was reduced in the post-intervention period: 30·2% vs 22·1%, aOR 0·71, 95% CI 0·52–0·96, p = 0·027. Cesarean section rates were significantly reduced in the univariate analysis: pre- 40·3% vs post-intervention 31·6% (p = 0·007). This reduction remained significant when adjusted for previous cesarean section, primiparity, maternal HIV infection and preterm birth (aOR 0·72, 95%CI 0·54–0·98, p = 0·035). Neonatal outcomes did not differ between the two groups.

Conclusion

The introduction of a clinical practice package of fetal heart rate monitoring education combined with routine UA cord lactate sampling has the potential to reduce the cesarean section rate without increasing adverse neonatal outcomes in a low-resource setting.

Neuroapoptosis in newborns with respiratory acidosis at birth

BACKGROUND

S100B protein is one of the most accurate biomarkers for diagnosis of neuroapoptosis and brain damage. The aim was to evaluate the lactate concentration and acid-base balance (pH, pCO₂, pO₂, HCO₃c and BEb) in umbilical cord blood to predict high risk of neuroapoptosis and analyze the relationship between the levels of these biomarkers and umbilical cord blood S100B protein concentration at birth.

METHODS

Apparently healthy newborns were included. S100B protein and blood gas test (lactate and acid-base balance) were determined in umbilical cord blood at birth. Newborns were classified into two groups: with and without high risk of neuroapoptosis. Newborns with high umbilical cord blood S100B protein concentration were considered newborns at high risk of neuroapoptosis.

RESULTS

Sixty-one newborns were included, 12 had high risk of neuroapoptosis and 49 did not. S100B protein concentration correlate directly with pCO₂ levels (Rho: 0.286, p = .0321) and lactate concentration (Rho: 0.278, p = .0315); and indirectly with pH (Rho: -0.332, p = .01). The analysis of the ROC curves yielded significant curves for pH and pCO₂ to predict high risk of neuroapoptosis, pH optimal cutoff value was 7.19 (sensitivity: 50%, specificity: 83.7%, AUC: 0.708); and pCO₂ optimal cutoff value was 60 mmHg (sensitivity: 30%, specificity: 85.4%, AUC: 0.705).

CONCLUSIONS

Respiratory acidosis is associated to high concentrations of S100B protein in umbilical cord blood at birth. Umbilical cord blood pH and pCO₂ may be useful in differentiating newborns at high risk of neuroapoptosis. Umbilical cord blood gas test may be valuable as risk indicator for neuroapoptosis at birth.

Preschool Language Outcomes following Perinatal Hypoxic-Ischemic Encephalopathy in the Age of Therapeutic Hypothermia

Early studies following perinatal hypoxic-ischemic encephalopathy (HIE) suggested expressive language deficits and academic difficulties, but there is only limited detailed study of language development in this population since the widespread adoption of therapeutic hypothermia (TH). Expressive and receptive language testing was performed as part of a larger battery with 45 children with a mean age of 26 months following perinatal HIE treated with TH. Overall cohort outcomes as well as the effects of gender, estimated household income, initial pH and base excess, and pattern of injury on neonatal brain MRI were assessed. The cohort overall demonstrated expressive language subscore, visual-reception subscore, and early learning composite scores significantly below test norms, with relative sparing of receptive language subscores. Poorer expressive language manifested as decreased vocabulary size and shorter utterances. Expressive language subscores showed a significant gender effect, and estimated socioeconomic status showed a significant effect on both receptive and expressive language subscores. Initial blood gas markers and modified Sarnat scoring did not show a significant effect on language subscores. Binarized MRI abnormality predicted a significant effect on both receptive and expressive language subscores; the presence of specific cortical/subcortical abnormalities predicted receptive language deficits. Overall, the language development profile of children following HIE in the era of hypothermia shows a relative strength in receptive language. Gender and socioeconomic status predominantly predict expressive language deficits; abnormalities detectable on MRI predominantly predict receptive language deficits.

Effect of Oxygen vs Room Air on Intrauterine Fetal Resuscitation: A Randomized Noninferiority Clinical Trial

IMPORTANCE

Two-thirds of women in labor receive supplemental oxygen to reverse perceived fetal hypoxemia and prevent acidemia. Oxygen is routinely administered for category II fetal heart tracings, a class of fetal tracing used to designate intermediate risk for acidemia. This liberal use of oxygen may not be beneficial, particularly because neonatal hyperoxygenation is harmful.

OBJECTIVE

To test the hypothesis that room air is noninferior to oxygen in improving fetal metabolic status among patients with category II fetal heart tracings.

DESIGN, SETTING, AND PARTICIPANTS

This was a randomized, unblinded noninferiority clinical trial conducted between June 2016 and July 2017 in the labor and delivery ward of a single tertiary care center. Women with singleton pregnancies at 37 weeks' gestational age or more who were admitted for delivery were eligible. Of those who met inclusion criteria, the patients who developed category II tracings in labor that necessitated intrauterine resuscitation were randomized in a 1:1 ratio to room air or oxygen. Analyses were intention-to-treat.

INTERVENTIONS

The oxygen group received 10 L of oxygen per minute by nonrebreather facemask until delivery. The room air group was exposed to room air only without a facemask.

MAIN OUTCOMES AND MEASURES

The primary outcome was umbilical artery lactate, a marker of metabolic acidosis and neonatal morbidity. Noninferiority was defined as a mean difference between groups of less than 9.0 mg/dL (1.0 mmol/L). Secondary outcomes were other umbilical artery gases, cesarean delivery for nonreassuring fetal status, and operative vaginal delivery.

RESULTS

Of the 705 patients who met inclusion criteria, 277 (39.3%) were enrolled on admission. During labor, 114 patients (41.2% of the enrolled patients) developed category II tracings and were randomized to room air (57 patients; 50.0% of the randomized patients) or oxygen (57 patients; 50.0% of the randomized patients). A total of 99 patients (86.8% of the randomized patients) with paired cord gases were included in the modified intention-to-treat analysis. The 99 patients included 76 African American women (77%); mean (SD) age was 27.3 (6.3) years in the oxygen group and 27.8 (5.3) years in the room air group. There was no difference in umbilical artery lactate between the group on oxygen and the group on room air (mean, 30.6 mg/dL [95% CI, 27.0 to 34.2 mg/dL] vs 31.5 mg/dL [95% CI, 27.9 to 36.0 mg/dL]); P = .69). The mean difference in lactate was 0.9 mg/dL (95% CI, -4.5 to 6.3 mg/dL), which was within the noninferiority margin. There was no difference in other umbilical artery gas components or mode of delivery between groups.

CONCLUSIONS AND RELEVANCE

Among patients with category II fetal heart tracings, intrauterine resuscitation with room air is noninferior to oxygen in improving umbilical artery lactate. The results of this trial challenge the efficacy of a ubiquitous obstetric practice and suggest that room air may be an acceptable alternative.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02741284.

The comparison of umbilical cord arterial blood lactate and pH values for predicting short-term neonatal outcomes

OBJECTIVE

Current clinical practice of assessing neonatal condition is based on evaluation of umbilical cord arterial blood pH value rather than lactate. However, evidence shows that lactate is direct and more predictive measurement than pH or at least of equal importance. This study is to assess and compare umbilical cord arterial lactate and pH values for predicting short-term neonatal outcomes.

MATERIALS AND METHODS

A retrospective cohort study was conducted at the tertiary level hospital, were arterial umbilical cord blood sampling was collected according to the standard procedures. Neonatal morbidity was registered if at least one of the following conditions was noted: Apgar score at 1 min after delivery was 6 or lower, resuscitation performed, including assisted ventilation and requirement of admission to neonatal intensive care unit. Mothers-newborns pairs were allocated into two groups: newborns exposed to perinatal hypoxia (group 1) and observed as healthy newborns (group 2). Receiver operating characteristics curves (ROC) were generated to assess the predictive ability of pH and lactate for the short-term neonatal outcomes.

RESULTS

901 neonates born at ≥37 weeks of gestation were included. Newborns exposed to perinatal hypoxia (group 1) encompassed 39 (4.3%) patients, and observed as healthy (group 2) - 862 (95.7%). Arterial umbilical cord blood pH in group 1 was 7.160 ± 0.126 as compared to 7.314 ± 0.083 in group 2; p < 0.001. Mean arterial lactate was significantly higher in group 1 than group 2 (6.423 ± 2.335 as compared to 3.600 ± 1.833; p < 0.001). The difference between areas under ROC curves representing pH and lactate was not significant (0.848 and 0.831 respectively; p = 0.6132).

CONCLUSION

Umbilical cord arterial lactate and pH predicted short-term neonatal outcomes with similar efficacies.

Critically ill neonates displayed stable vital parameters and reduced metabolic acidosis during neonatal emergency airborne transport in Sweden

AIM

This study evaluated the medical quality of acute airborne transports carried out by a neonatal emergency transport service in a Swedish healthcare region from 2012 to 2015.

METHODS

The transport charts and patient records of all infants transported to the regional centre were reviewed for transport indications and vital parameters and outcomes.

RESULTS

We identified 187 acute airborne transports and the main indications for referral were therapeutic hypothermia after perinatal asphyxia, extremely preterm birth and respiratory failure. There were 37 deaths, but none of these occurred during transport and none of the deaths that occurred within 24 hours after transport were found to be related to the transport per se. No differences were found in vital parameters or ventilator settings before and after transport, except for an improvement in blood pH (7.22 ± 0.13 versus 7.27 ± 0.13, mean ± SD, p < 0.01), due to a decrease in base deficit (-8.0 ± 6.8 versus -5.4 ± 6.3 mmol, p < 0.001), while the partial pressure of carbon dioxide remained unchanged.

CONCLUSION

During air transport, critically ill neonates displayed stable vital parameters and reduced metabolic acidosis. No transport-related mortality was found, but the high number of extremely preterm infants transported indicates the potential for improving in-utero transport.

Point-of-care umbilical arterial lactate and newborn outcomes in a low resource setting: cohort study

Objective

Birth asphyxia contributes substantially to the burden of intrapartum stillbirth and neonatal mortality in resource limited countries. We investigated clinical correlates and neonatal outcomes of lactate analysis of umbilical arterial cord blood in a large referral maternity unit in Malawi using a point-of-care test (Lactate Xpress, Nova Biomedical, Runcorn, UK) and examined maternal and neonatal characteristics and outcomes.

Results

There were 389 live births and 12 intrapartum stillbirths during the study. The median umbilical arterial lactate concentration was 3.4 mmol/L (interquartile range 2.6–4.9). Umbilical arterial lactate concentrations among the 45 babies admitted for special neonatal care were above 5 mmol/L in 16/45 (36%) of cases, with no fatality below 13 mmol/L. A positive malaria rapid diagnostic test was associated with hyperlactatemia (p < 0.05). In receiver-operator characteristic (ROC) analysis using a lactate cutoff of 5 mmol/L, areas under the curve were 0.72 (95% CI 0.66–0.79) and 0.64 (95% CI 0.58–0.69) for the Apgar score at 1 and 5 min respectively. This approach can identify safely those newborns that are unlikely to require additional monitoring. Scale-up implementation research in low resource country referral units is needed. The influence of malaria on neonatal hyperlactatemia requires further exploration.

Impact of maternal HIV on umbilical cord lactate measurement at delivery in a South African labor ward

OBJECTIVE

To assess umbilical artery lactate levels and perinatal outcomes among women with and without HIV infection.

METHODS

The present prospective cohort study recruited women planning to undergo vaginal delivery at Kalafong Hospital, South Africa, between March 3 and November 12, 2014. Umbilical artery lactate levels were measured and perinatal outcome data were recorded. Outcome analyses were stratified by maternal HIV status, and a subgroup analysis was performed where women with a CD4 count below 350 × 10⁶ cells/L were compared with women without HIV.

RESULTS

In total, 936 women with singleton fetuses were enrolled. Maternal HIV status was available for 897 (95.8%) participants, of whom 202 (21.6%) had HIV infections. Overall, 186 (92.1%) women with HIV infections received prophylaxis or treatment. There was no difference between participants with and without HIV infections in the preterm delivery rate (P=0.770), mode of delivery (P=0.354), neonatal resuscitation rate (P=0.717), 1- or 5-minute Apgar scores below 7 (P=0.353), or the rate of having an umbilical artery lactate level above 5.45 mmol/L (P=0.301). Similarly, there were no differences in outcomes in the subgroup analysis of women with a CD4 count below 350 × 10⁶ cells/L.

CONCLUSION

Umbilical artery lactate levels and perinatal outcomes were found to be comparable between patients with and without HIV infections in a South African setting.