Fetal Scalp Lactate Research Articles

The impact of body mass index on labour management and mode of delivery: A retrospective matched cohort study.

This study aims to examine the association between body mass index (BMI) and mode of delivery, progression of labour, and intrapartum interventions. This was a retrospective matched cohort study including Class III obese (BMI ≥40 kg/m2) and normal BMI (BMI <25 kg/m2) women planning a vaginal birth who had a live, singleton delivery from January 2015 to December 2018. Patients were matched (1:1) based on age, gestational age, parity, onset of labour and birth weight. The primary outcome was caesarean delivery (CD). Secondary outcomes were delivery outcomes, intrapartum management and interventions. Rates of each outcome were compared with matched analysis, and duration of labour with time-to-event analysis. We studied two groups of 300 pregnant women. The CD rate was significantly higher for obese women than the normal BMI cohort (19.3% vs 13.3%; risk ratio (RR) 1.43, 95% CI 1.02-1.98, P = 0.035). Cervical dilation prior to CD for failure to progress was slower in obese than normal BMI (0.04 vs 0.16 cm/h). The obese cohort had a longer duration of labour in those who underwent induction (13.70 vs 11.48 h, P = 0.024). Intrapartum intervention rates were higher for obese women, with significant differences in rates of fetal scalp electrodes (72.7% vs 22.7%, RR 3.20, 95% CI 2.58-3.99, P < 0.001), intrauterine pressure catheters (18.3% vs 0%, P < 0.001), epidural analgesia (44.0% vs 37.0%, RR 1.20, 95% CI 1.01-1.44, P = 0.040) and fetal scalp lactate sampling (8.0% vs 3.0%, RR = 2.67, 95% CI 1.33-5.33, P = 0.004). Class III obesity is associated with an increased risk of CD and intrapartum interventions.

AACC Guidance Document on the Use of Point-of-Care Testing in Fertility and Reproduction.

The AACC Academy revised the reproductive testing section of the Laboratory Medicine Practice Guidelines: Evidence-Based Practice for Point-of-Care Testing (POCT) published in 2007. A panel of Academy members with expertise in POCT and laboratory medicine was formed to develop guidance for the use of POCT in reproductive health, specifically ovulation, pregnancy, premature rupture of membranes (PROM), and high-risk deliveries. The committee was supplemented with clinicians having Emergency Medicine and Obstetrics/Gynecology training. Key recommendations include the following. First, urine luteinizing hormone (LH) tests are accurate and reliable predictors of ovulation. Studies have shown that the use of ovulation predicting kits may improve the likelihood of conception among healthy fertile women seeking pregnancy. Urinary LH point-of-care testing demonstrates a comparable performance among other ovulation monitoring methods for timing intrauterine insemination and confirming sufficient ovulation induction before oocyte retrieval during in vitro fertilization. Second, pregnancy POCT should be considered in clinical situations where rapid diagnosis of pregnancy is needed for treatment decisions, and laboratory analysis cannot meet the required turnaround time. Third, PROM testing using commercial kits alone is not recommended without clinical signs of rupture of membranes, such as leakage of amniotic fluid from the cervical opening. Finally, fetal scalp lactate is used more than fetal scalp pH for fetal acidosis due to higher success rate and low volume of sample required. This revision of the AACC Academy POCT guidelines provides recommendations for best practice use of POCT in fertility and reproduction.

Fetal heart block: Vaginal delivery an option.

Fetal heart block (FHB) occurs in approximately 1:20 000 births and is associated with significant morbidity and mortality. Vaginal delivery with intrapartum fetal scalp lactate monitoring is offered as an option at our centre for selected cases, in contrast with the published literature advocating caesarean birth. To review perinatal outcomes at delivery for FHB at a tertiary referral hospital. Ours was a retrospective cohort study from 1 January, 2007 to 30 June, 2020. The infant outcomes are summarised in three delivery groups: vaginal delivery, planned caesarean section (CS) and unplanned CS. There were 23 newborns in the study period, with a median gestation at birth of 37.2 weeks and there was one antepartum fetal death in this cohort. Vaginal delivery was planned in 12 women: eight had normal births, three of these women progressed to an intrapartum (unplanned) CS and one woman had a planned CS. All live babies in the vaginal delivery cohort had an Apgar score greater than seven at five minutes. Of the 22 newborns, six required intubation, of which five had been delivered by a planned CS. Our data suggest that planned vaginal delivery is a safe option for selected women carrying a fetus with FHB. Managing labour with serial fetal scalp lactates, and the involvement of senior clinicians are important factors in achieving a successful outcome.

Effectiveness of intrapartum fetal surveillance to improve maternal and neonatal outcomes: a systematic review and network meta-analysis

BACKGROUND:Cesarean delivery is the most common surgical procedure worldwide. Intrapartum fetal surveillance is routinely offered to improve neonatal outcomes, but the effects of different methods on the risk of emergency cesarean deliveries remains uncertain. We conducted a systematic review and network meta-analysis to evaluate the effectiveness of different types of fetal surveillance.METHODS:We searched MEDLINE, Embase and CENTRAL until June 1, 2020, for randomized trials evaluating any intrapartum fetal surveillance method. We performed a network meta-analysis within a frequentist framework. We assessed the quality and network inconsistency of trials. We reported primarily on intrapartum emergency cesarean deliveries and other secondary maternal and neonatal outcomes using risk ratios (RRs) and 95% confidence intervals (CIs).RESULTS:We included 33 trials (118 863 patients) evaluating intermittent auscultation with Pinard stethoscope/handheld Doppler (IA), cardiotocography (CTG), computerized cardiotocography (cCTG), CTG with fetal scalp lactate (CTG-lactate), CTG with fetal scalp pH analysis (CTG-FBS), CTG with fetal pulse oximetry (FPO-CTG), CTG with fetal heart electrocardiogram (CTG-STAN) and their combinations. Intermittent auscultation reduced the risk of emergency cesarean deliveries compared with other types of surveillance (IA v. CTG: RR 0.83, 95% CI 0.72–0.97; IA v. CTG-FBS: RR 0.71, 95% CI 0.63–0.80; IA v.CTG-lactate: RR 0.77, 95% CI 0.64–0.92; IA v. FPO-CTG: RR 0.75, 95% CI 0.65–0.87; IA v.FPO-CTG-FBS: RR 0.81, 95% CI 0.67–0.99; cCTG-FBS v. IA: RR 1.21, 95% CI 1.04–1.42), except STAN-CTG-FBS (RR 1.17, 95% CI 0.98–1.40). There was a similar reduction observed for emergency cesarean deliveries for fetal distress. None of the evaluated methods was associated with a reduced risk of neonatal acidemia, neonatal unit admissions, Apgar scores or perinatal death.INTERPRETATION:Compared with other types of fetal surveillance, intermittent auscultation seems to reduce emergency cesarean deliveries in labour without increasing adverse neonatal and maternal outcomes.

398 The impact of BMI on management of labour: A retrospective matched cohort analysis

Maternal obesity is a major challenge to safe obstetric practice with higher rates of intrapartum complications, failed induction of labour (IOL) and emergency caesarean delivery (CD). We investigated the impact of obesity on labour outcomes and interventions. Class III obese (BMI >40 Kg/m2) and normal BMI (<25 Kg/m2) patients who delivered from 2015-2018 were matched (1:1) based on age, gestational age, parity, onset of labour, and birth weight. Patients with previous CD, IOL < 37 weeks, maternal age <18 years or stillbirth were excluded. The primary outcome was CD. Secondary outcomes were instrumental delivery, cervical dilation at decision for CD, dilation rate prior to decision for CD for labour progress, oxytocin augmentation, and intrapartum interventions (epidural analgesia, fetal scalp electrode (FSE), intrauterine pressure catheter (IUPC), fetal scalp lactate, terbutaline use). Of 600 matched patients, 50% were primigravidae (PG). Half of both PG and multigravidae groups underwent IOL. CD rate was higher for obese (oBMI) patients (19.3%) than the normal BMI (nBMI) cohort (13.3%, RR 1.45, CI 1.00-2.09, p = 0.049). Instrumental deliveries occurred less in oBMI (16.7%) than with nBMI (24.0%, RR 0.89, CI 0.50-0.96, p = 0.027). Median cervical dilation at CD was lower for oBMI (4 cm) than nBMI (6 cm), even when comparing only CD for poor progress (5 cm vs 7 cm). Rate of dilation prior to CD for poor progress was lower in oBMI (0.04cm/hr) than nBMI (0.16cm/hr). In CD patients, oxytocin was used less often for oBMI (75.8% vs 85.0%, RR 0.89, CI 0.73-1.08, p = 0.253) but with a higher mean total dose (12.3 IU vs 11.9 IU). Rates of intrapartum intervention were higher for oBMI, particularly FSE (72.7% vs 22.7%, RR 3.21, CI 2.52-3.99, p < 0.001) and IUPC (55% vs 0%, p < 0.001). Obesity increased the risk of CD, and CD for poor progress occurred at a lower cervical dilation in the obese cohort, with a slower rate of dilation prior to CD. Intrapartum interventions occurred more in the obese cohort.

Верификация результатов пробы скальп-лактат при использовании портативного лактометра

Верификация результатов пробы скальп-лактат при использовании портативного лактометра

No. 197b-Fetal Health Surveillance: Intrapartum Consensus Guideline.

This guideline provides new recommendations pertaining to the application and documentation of fetal surveillance in the intrapartum period that will decrease the incidence of birth asphyxia while maintaining the lowest possible rate of obstetrical intervention. Pregnancies with and without risk factors for adverse perinatal outcomes are considered. This guideline presents an alternative classification system for antenatal fetal non-stress testing and intrapartum electronic fetal surveillance to what has been used previously. This guideline is intended for use by all health professionals who provide intrapartum care in Canada. Consideration has been given to all methods of fetal surveillance currently available in Canada. Short- and long-term outcomes that may indicate the presence of birth asphyxia were considered. The associated rates of operative and other labour interventions were also considered. A comprehensive review of randomized controlled trials published between January 1996 and March 2007 was undertaken, and MEDLINE and the Cochrane Database were used to search the literature for all new studies on fetal surveillance antepartum. The level of evidence has been determined using the criteria and classifications of the Canadian Task Force on Preventive Health Care (Table1). This consensus guideline was jointly developed by the Society of Obstetricians and Gynaecologists of Canada and the British Columbia Perinatal Health Program (formerly the British Columbia Reproductive Care Program or BCRCP) and was partly supported by an unrestricted educational grant from the British Columbia Perinatal Health Program. RECOMMENDATION 1: LABOUR SUPPORT DURING ACTIVE LABOUR: RECOMMENDATION 2: PROFESSIONAL ONE-TO ONE CARE AND INTRAPARTUM FETAL SURVEILLANCE: RECOMMENDATION 3: INTERMITTENT AUSCULTATION IN LABOUR: RECOMMENDATION 4: ADMISSION FETAL HEART TEST: RECOMMENDATION 5: INTRAPARTUM FETAL SURVEILLANCE FOR WOMEN WITH RISK FACTORS FOR ADVERSE PERINATAL OUTCOME: When a normal tracing is identified, it may be appropriate to interrupt the electronic fetal monitoring tracing for up to 30 minutes to facilitate periods of ambulation, bathing, or position change, providing that (1) the maternal-fetal condition is stable and (2) if oxytocin is being administered, the infusion rate is not increased (III-B). RECOMMENDATION 6: DIGITAL FETAL SCALP STIMULATION: RECOMMENDATION 7: FETAL SCALP BLOOD SAMPLING: RECOMMENDATION 8: UMBILICAL CORD BLOOD GASES: RECOMMENDATION 9: FETAL PULSE OXIMETRY: RECOMMENDATION 10: ST WAVEFORM ANALYSIS: RECOMMENDATION 11: INTRAPARTUM FETAL SCALP LACTATE TESTING.

288: Fetal scalp lactate and digital scalp stimulation among those with non-reassuring fetal heart tracings: A decision analytic model

288: Fetal scalp lactate and digital scalp stimulation among those with non-reassuring fetal heart tracings: A decision analytic model

Involving the consultant before fetal blood sampling.

Fetal scalp lactate (FSL) is used when the cardiotocography (CTG) is not normal in an attempt to reduce the false-positive rate and the likelihood of unnecessary intervention. Whilst the test has almost a 100% negative predictive value, the positive predictive value of this test is very low. To measure the effect of introducing consultant obstetrician review of every abnormal CTG prior to the decision toperform FSL. A retrospective cohort study was performed using routinely collected de-identified data. Mode of birth outcomes for women who had a continuous CTG in labour were compared in two equal time periods, 12months before and after a change in hospital policy. Change in hospital policy dictated that FSL was only performed on a pathological CTG after consultant obstetrician review of the CTG. Consultant obstetrician review of CTG prior to FSL was associated with fewer FSL performed (1.7% vs 3.5%; P≤0.01), fewer babies acidaemic at birth pH<7.1 (0.8% vs 2.2%; P<0.01), fewer caesarean sections for presumed fetal distress (CS for FD) (6.6% vs 8.1%; P=0.05) and fewer instrumental births (17.6% vs 20%; P=0.04). When adjusted for confounders, the change in policy was independently associated with a reduced likelihood of CS for FD (adjusted odds ratios=0.78 (0.63-0.97); P=0.03). A hospital policy whereby a consultant obstetrician reviews abnormal CTGs prior to performing FSL mayhelp to increase the pretest probability and reduce the rate of CS for FD, as well as instrumental birth and unnecessary FSL.

Fetal scalp blood lactate during second stage of labor: determination of reference values and impact of obstetrical interventions

Objective: To determine the reference interval of fetal scalp blood lactate during second stage of labor.Material: Two hundred and fifty-three women in first stage of labor with a reassuring CTG were asked for permission to sample fetal scalp blood during second stage.Results: In cases with reassuring CTG and five minute Apgar score ≥9, the mean lactate value (±2 SD) was 2.5 mmol/L (lower limit 1.1, higher limit 5.2). The lactate concentration was significantly higher among nulliparous and in cases with use of epidural or oxytocin (p <0.001). There was a moderate positive correlation between scalp lactate values and active pushing time. When parity, epidural, oxytocin and active pushing time were analyzed together, they had equal influence on lactate values (p <0.001). Higher lactate values were associated with intermediate/pathological CTG compared to normal CTG (p <0.001). There was no correlation to gestational age or birthweight (p = 0.72, respectively 0.43).Conclusions: The reference interval of fetal scalp lactate during second stage is 1.1–5.2 mmol/L. Parity, use of epidural or oxytocin and the duration of pushing are associated to increased lactate concentration; however, we could not demonstrate any correlation to advancing gestational age or birthweight.

Should fetal scalp blood sampling be performed in the case of meconium-stained amniotic fluid?

Objective: To investigate the effect of using fetal scalp blood sampling on the risk of neonatal respiratory distress syndrome (NRDS) with meconium-stained amniotic fluid (MSAF).Methods: Prospective data collection with regard to MSAF during labor for low-risk term cephalic singleton live birth from 2012 to 2014. Maternal, obstetric and neonatal data were compared according to the occurrence of respiratory distress syndrome (RDS group) or not (no RDS group).Results: Of 515 newborns born through MSAF, 46 experienced RDS and from them 10 experienced meconium aspiration syndrome. No difference was observed according to maternal characteristic, abnormal fetal heart rate tracing pattern irrespective of its category and cesarean rate. Apgar at one minute was lower in the group RDS (7.6 versus 8.5, p < 0.05). The mean umbilical artery pH values did not differ between the two groups. Significant difference between newborns with and without RDS in terms of fetal scalp lactate sampling during the labor (71.1% versus 55.1%, p < 0.05), and neonatal care unit (NCU) admissions (22.8% versus 10.8%, p < 0.05). Secondary rather than primary meconium was associated with RDS when performing fetal scalp blood assessment (p < 0.05). A significant correlation between RDS, fetal scalp blood assessment and MSAF diagnosed during the first stage of labor (after spontaneous rupture of membranes or at amniotomy) was found.Conclusion: In case of MSAF, fetal scalp blood sampling did not reduce the risk of RDS.

A Study of Various Factors Influencing Fetal Scalp Lactate and Their Correlation With Composite Fetal and Neonatal Outcomes

Background: Fetal scalp lactate has been shown to be as effective as fetal scalp pH in predicting neonatal outcomes. Maternal-fetal factors influencing variability in fetal scalp lactate have not been fully explored. This study aims to explore the association of gestational age with fetal scalp lactate and examine whether existing thresholds are predictive of adverse outcomes. Methods: A retrospective study of all singleton births with a fetal scalp lactate taken during labor at a public teaching hospital between July 1, 2007 and June 1, 2013 was performed. Descriptive, bivariate and multivariate analysis was used to explore the association between fetal scalp lactate and other variables of interest. Results: A total of 326 patients with fetal scalp lactate values during labor were studied. Fetal scalp lactate was not associated with gestational age (Spearman’s rho = -0.006, P = 0.92). A fetal scalp lactate ≥ 4.8 mmol/L was associated with maternal age (P = 0.049) and time in labor (P = 0.001). Fetal scalp lactate was strongly associated with a combined outcome variable that included emergency operative delivery (OR = 1.90; 95% CI: 1.44 - 2.51; P < 0.001). There was no significant association with a poor combined fetal and neonatal outcome when emergency intervention was excluded (OR = 1.11; 95% CI: 0.93 - 1.25; P = 0.092). Conclusions: There was no significant correlation between fetal scalp lactate and gestational age; further exploration of the association with maternal age is warranted. A raised fetal scalp lactate is associated with progression to emergency operative delivery. J Clin Gynecol Obstet. 2015;4(2):212-216 doi: http://dx.doi.org/10.14740/jcgo329w Normal 0 false false false EN-AU X-NONE X-NONE

Lactate versus pH levels in fetal scalp blood during labor – using the Lactate Scout System

Objective: To assess if lactate measured with the Scout Lactate System is a reliable alternative to pH in intrapartum monitoring of the fetus.Methods: A prospective study analyzing (1) the correlation between scalp lactate measured by the Scout Lactate System and the Automatic Blood Laboratory (ABL), (2) the correlation between lactate and pH measured in scalp blood and (3) the correlation between fetal scalp lactate and umbilical cord SBE. The sensitivity/specificity and positive/negative predictive values of lactate in predicting low pH were analyzed and expressed as Receiver Operating Curves (ROC).Results: Lactate measured by the Scout Lactate System and the ABL correlated well (r2 = 0.85). Both lactate and pH were measured in 1009 scalp blood samples. The sensitivity and specificity of lactate ≥4.8 mmol/l in predicting a pH <7.20 were 0.63 and 0.85, respectively. The correlation between scalp lactate measured within 15 min prior to delivery and the umbilical cord SBE was low.Conclusion: Monitoring non-reassuring deliveries with scalp lactate instead of pH would have resulted in more (155 instead of 56) instrumental deliveries with no decrease in newborns with severe metabolic acidosis.

Intrapartum fetal scalp lactate sampling for fetal assessment in the presence of a non-reassuring fetal heart rate trace.

Fetal scalp blood sampling for lactate estimation may be considered following identification of an abnormal or non-reassuring fetal heart rate pattern. The smaller volume of blood required for this test, compared with the more traditional pH estimation, may improve sampling rates. The appropriate use of this practice mandates systematic review of its safety and clinical effectiveness prior to widespread introduction. To evaluate the effectiveness and risks of fetal scalp lactate sampling in the assessment of fetal well-being during labour, compared with no testing or alternative testing. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015). All published and unpublished randomised and quasi-randomised trials that compared fetal scalp lactate testing with no testing or alternative testing to evaluate fetal status in the presence of a non-reassuring cardiotocograph during labour. We used the standard methodological procedures of the Cochrane Pregnancy and Childbirth Group. Two review authors independently assessed the studies. The search identified two completed randomised controlled trials (RCTs) and two ongoing trials. The two published RCTs considered outcomes for 3348 mother-baby pairs allocated to either lactate or pH estimation of fetal blood samples when clinically indicated in labour. Overall, the published RCTs were of low or unclear risk of bias. There was a high risk of performance bias, because it would not have been feasible to blind clinicians or participants.No statistically significant between-group differences were found for neonatal encephalopathy (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.32 to 3.09, one study, 2992 infants) or death. No studies reported neonatal seizures. We had planned to report death with other morbidities, for example, neonatal encephalopathy; however, the data were not available in a format suitable for this, therefore death due to congenital abnormality was considered alone. The three reported neonatal deaths occurred in babies with diaphragmatic hernias (n = 2) or congenital cardiac fibrosis (n = 1). All three babies had been randomised to the pH group and were not acidaemic at birth.There were no statistically significant differences for any of the pre-specified secondary fetal/neonatal/infant outcomes for which data were available. This included low Apgar score at five minutes (RR 1.13, 95% CI 0.76 to 1.68, two studies, 3319 infants) and admission to neonatal intensive care units (RR 1.02, 95% CI 0.83 to 1.25, one study, 2992 infants), or metabolic acidaemia (RR 0.91, 95% CI 0.60 to 1.36, one study, 2675 infants) considered within the studies, either overall or where data were available for those where fetal blood sampling had occurred within 60 minutes of delivery.Similar proportions of fetuses underwent additional tests to further evaluate well-being during labour, including scalp pH if in the lactate group or scalp lactate if in the pH group (RR 0.22, 95% CI 0.04 to 1.30, two studies, 3333 infants;Tau² 1.00, I² = 58%). Fetal blood sampling attempts for lactate and pH estimation were successful in 98.7% and 79.4% of procedures respectively in the one study that reported this outcome.There were no significant between-group differences in mode of birth or operative birth for non-reassuring fetal status, either for all women, or within the group where the fetal blood sample had been taken within 60 minutes of delivery (for example, caesarean section for all enrolled, RR 1.09, 95% CI 0.97 to 1.22, two studies, 3319 women; operative delivery for non-reassuring fetal status for all enrolled RR 1.02, 95% CI 0.93 to 1.11, one study, 2992 women).Neither study reported on adverse effects of fetal scalp lacerations or maternal anxiety. When further testing to assess fetal well-being in labour is indicated, fetal scalp blood lactate estimation is more likely to be successfully undertaken than pH estimation. Further studies may consider subgroup analysis by gestational age, the stage of labour and sampling within a prolonged second stage of labour. Additionally, we await the findings from the ongoing studies that compare allocation to no fetal blood sample with sampling for lactate and address longer-term neonatal outcomes, maternal satisfaction with intrapartum fetal monitoring and an economic analysis.

A Study of Various Factors Influencing Fetal Scalp Lactate and Their Correlation With Composite Fetal and Neonatal Outcomes

A Study of Various Factors Influencing Fetal Scalp Lactate and Their Correlation With Composite Fetal and Neonatal Outcomes

Comparison of the Nova StatStrip(R) Lactate versus the Arkray Lactate Pro(R) meters for fetal scalp lactate measurement

Comparison of the Nova StatStrip(R) Lactate versus the Arkray Lactate Pro(R) meters for fetal scalp lactate measurement

Electronic Fetal Heart Rate Monitoring: The Future

Continuous electronic fetal heart rate monitoring (EFM) using a cardiotocograph (CTG) is associated with a high false positive rate of approximately 60%. Current scientific evidence does not support a significant reduction in perinatal mortality or cerebral palsy, except for a 50% reduction in neonatal convulsions. Recent scientific evidence has questioned the role of ‘peripheral’ tests of fetal wellbeing such as fetal scalp blood sampling (FBS), fetal scalp lactate and fetal pulse oximetry in reducing the false positive rate of CTG. Fetal ECG (ST-Analyzer or STAN) shows promise in reducing neonatal admissions and operative vaginal births. Computerized CTG analysis and Fetal Physiological Score (FPS) may help reduce errors associated with CTG interpretation. Keywords: Fetal scalp blood sampling, fetal scalp lactate, ST-Analyzer (STAN), Fetal Physiological Score (FPS), computerised analysis.

Comparing fetal scalp lactate and umbilical cord arterial blood gas values

Fetal scalp lactate has been shown to be as effective as scalp pH in predicting fetal outcomes. However, there is limited clinical evidence to demonstrate a strong correlation with fetal acidaemia at birth. To compare the diagnostic accuracy of fetal scalp lactate and umbilical cord arterial blood gas values sampling, as it is used in clinical practice. A retrospective cohort study was performed on 661 term (≥37 weeks) births where a fetal scalp lactate sample was taken during labour. Cases were excluded where either the lactate was taken greater than 1 h prior to delivery, incomplete cord gas analyses were available, or a sentinel hypoxic event occurred prior to delivery. The final data set included 229 microvolume scalp lactate measurements which were compared with neonatal paired cord blood gas values taken at delivery. A fetal scalp lactate measurement of ≥4.8 mmol/L had a positive predictive value (PPV) of 1% and a negative predictive value (NPV) of 100% in predicting umbilical artery pH ≤7.00, and a PPV of 5% and a NPV of 98% in predicting umbilical artery pH ≤7.10. The sensitivity and specificity for these values were 100%, 23% and 90%, 23%, respectively. Fetal scalp lactate microsampling has a strong negative predictive value for fetal acidaemia at birth.

Accuracy of a hand-held lactate meter in measuring umbilical cord blood lactate at all lactate levels

Objective: Fetal scalp lactate has largely replaced pH analysis to assess intrapartum hypoxia. Many obstetrics units use hand-held lactate meters to measure umbilical blood because of its affordability and ease of use. We sought to investigate the agreement of Lactate ProTM with a reference method blood gas analyser and to determine its usefulness with a recommended cutoff value of 4.8 mmol/L. Methods: Prospective study carried out at a tertiary institution where 237 arterial and 233 venous samples from umbilical cords of 16 elective caesarean and 285 emergency deliveries were measured using Lactate ProTM and ABL735 Sesries Acid-Base analyser. Limits of agreement were analysed using Bland-Altman plots. Results: Lactate ProTM differentiated fewer deliveries as “high risk” (≥4.8 mmol/L) and more as “low risk” (TM) were –1.46 - 0.97 mmol/L for arterial lactate levels arterial lactate levels ≥ 4.8 mmol/L. Conclusion: There was a poorer agreement between the two devices at higher lactate values. Lactate ProTM underestimates by up to 3.2 mmol/L; a 4.8 mmol/L reading may actually signify a lactate level of 8.0 mmol/L, indicating severe metabolic acidosis. We caution the use of this device in assessing fetal lactate levels.

Rational approach to electronic fetal monitoring during labour in 'all' resource settings

Electronic fetal monitoring (EFM) involves the use of cardiotocograph (CTG) to asses fetal wellbeing during labour in order to detect intrapartum fetal hypoxia early so as to institute timely and appropriate action. Indeed, when CTG was introduced into obstetric practice in the 1960s, it was expected to prevent perinatal brain injury and reduce the incidence of short term (neonatal admissions, seizures and neonatal deaths) and long term (cerebral palsy, learning difficulties) that arise secondary to intrapartum hypoxic insults. Unfortunately, although the rates of caesarean sections have dramatically increased over the last 40 years, there has been virtually no change in cerebral palsy rates. However, increasing caesarean section rates have contributed to maternal morbidity and mortality, including rising incidence of morbidly adherent placentae (placenta accrete, increta and percreta). Apart from a high 'false positive' rate of CTG, failure to appreciate the pathophysiology of fetal heart rate changes by the clinicians have contributed to increased operative deliveries, without any substantial improvements in neonatal outcomes. Hence, a rational approach is warranted in the use and interpretation of CTGs to improve maternal and fetal outcomes, in all settings, irrespective of the availability of additional tests of fetal wellbeing such as fetal blood sampling (FBS), fetal electrocardiograph (ST analyser or STAN), fetal pulse oximetry or scalp lactate. DOI: <a href="http://dx.doi.org/10.4038/sljog.v32i4.3988">http://dx.doi.org/10.4038/sljog.v32i4.3988</a> <em>SLJOG </em>2010; 32(4): 77-84