Eva Wiberg-Itzel

Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress: randomised controlled multicentre trial

Objective To examine the effectiveness of pH analysis of fetal scalp blood compared with lactate analysis in identifying hypoxia in labour to prevent acidaemia at birth. Design Randomised controlled multicentre trial. Setting Labour wards. Participants Women with a singleton pregnancy, cephalic presentation, gestational age ≥34 weeks, and clinical indication for fetal scalp blood sampling. Interventions Standard pH analysis (n=1496) or lactate analysis (n=1496) with an electrochemical microvolume (5 μl) test strip device. The cut-off levels for intervention were pH <7.21 and lactate >4.8 mmol/l, respectively. Main outcome measure Metabolic acidaemia (pH <7.05 and base deficit >12 mmol/l) or pH <7.00 in cord artery blood. Results Metabolic acidaemia occurred in 3.2% in the lactate group and in 3.6% in the pH group (relative risk 0.91, 95% confidence interval 0.61 to 1.36). pH <7.00 occurred in 1.5% in the lactate group and in 1.8% in the pH group (0.84, 0.47 to 1.50). There was no significant difference in Apgar scores <7 at 5 minutes (1.15, 0.76 to 1.75) or operative deliveries for fetal distress (1.02, 0.93 to 1.11). Conclusion There were no significant differences in rate of acidaemia at birth after use of lactate analysis or pH analysis of fetal scalp blood samples to determine hypoxia during labour. Trial registration ISRCT No 1606064.

Angiopoietin-1/Angiopoietin-2 Ratio for Prediction of Preeclampsia

BACKGROUND A number of different biophysical and biochemical markers have been proposed as predictors of preeclampsia. Factors involved in the angiogenic balance are suggested as candidate markers. The purpose of this prospective, longitudinal cohort study was to determine whether a ratio between Angiopoietin-1 (Ang-1) and Angiopoietin-2 (Ang-2) can be used to predict preeclampsia in a low-risk population. METHODS A cohort of healthy pregnant women (n = 469) were enrolled at gestational weeks 8-12. Plasma samples were collected at gestational weeks 10, 25, 28, 33, and 37. By using commercially available enzyme-linked immunosorbent assay kits Ang-1 and Ang-2 were analyzed. RESULTS The median Ang-1/Ang-2 ratio increased during pregnancy in all women, but the ratios were significantly lower at gestational weeks 25 and 28 in women who later developed preeclampsia than in normal pregnant women (1.49 compared to 2.19 and 2.12 compared to 3.54, P < 0.05 and P < 0.05). CONCLUSION Our data indicate that in a low-risk population of women the Ang-1/Ang-2 ratio in plasma constitutes a possible biomarker for prediction of later onset of preeclampsia.

Lactate dehydrogenase predicts hypoxic ischaemic encephalopathy in newborn infants: a preliminary study

Background:  Enzyme leakage as a result of hypoxia‐ischaemia induced cell damage in affected organs is seen together with hypoxic ischaemic encephalopathy (HIE) after perinatal asphyxia.

Lactate determination in vaginal fluids: a new method in the diagnosis of prelabour rupture of membranes

Objectives  To assess whether lactate determination in vaginal fluids, ‘Lac test’, can be used as a diagnostic test for prelabour rupture of membranes (PROM) and to derive the best cutoff value for a positive test.

Association between lactate concentration in amniotic fluid and dysfunctional labor

Objectives. To assess whether there is an association between high lactate concentration in amniotic fluid (AF) and labor dystocia. Design. Prospective observational study. Setting. Labor ward at General South Hospital, Stockholm, Sweden. Population and methods. Women in active labor attending labor ward, having at least two consecutive measurements of lactate concentration in AF, measured 60 minutes apart. Main outcome measure. Dysfunctional labor, defined as instrumental or operative delivery due to dystocia. Results. Among women with spontaneous vaginal deliveries (n =23) the mean lactate concentration in AF during labor was 8.9 mmol/l (range 6.6–10.8), and among women with operative delivery due to labor dystocia (n =31) the corresponding value was 10.9 mmol/l (range 8.0–16.1) (p<0.001). Of 29 women with a high lactate concentration (≥10.1 mmol/l) in at least two consecutive measures collected at least 60 minutes apart, 25 (86%) were delivered instrumentally/operatively due to dystocia. Using this definition of a positive test, the diagnostic accuracy to predict operative delivery due to dystocia was: sensitivity 81% (25/31), specificity 83% (19/23), positive predictive value 86% (25/29), and negative predictive value 76% (19/25). The likelihood ratio was 5.0 for a positive test and 0.2 for a negative test. Conclusions. High lactate concentration (≥10.1mmol/l) in at least two consecutive samples of AF collected during labor 60 minutes apart is strongly associated with dystocia. This method might be useful in clinical management to identify labor dystocia at an early stage of labor.

Association between lactate in vaginal fluid and time to spontaneous onset of labour for women with suspected prelabour rupture of the membranes.

Objectives  To assess whether lactate determination in vaginal fluid is associated with, and can predict, onset of labour for women with suspected prelabour rupture of the membranes (PROM).

Lactate concentration in amniotic fluid : a good predictor of labor outcome

OBJECTIVE Previous publications have suggested that high levels of lactate in amniotic fluid (AF) correlate with dysfunctional labor. The aim of this study was to investigate whether lactate concentration in AF together with the partogram is a better predictor of operative intervention in dysfunctional labor than the partogram alone. STUDY DESIGN A prospective observational study was carried out of 825 laboring women. Samples of AF were collected and the lactate concentration was analyzed at the bedside during labor. The main outcome of the study was the method of delivery (operative/spontaneous vaginal) in relation to the concentration of lactate in AF. Logistic regression was used to estimate the association between lactate concentration in AF and labor outcome and to adjust for well-known risk factors for dysfunctional labor. RESULTS 385/825 women had an arrested labor according to the partogram, and 193 of them were delivered operatively. High lactate in AF (>10.1 mmol/l) when labor arrested was associated with an increased risk of operative intervention due to dysfunctional labor (adjusted OR, 5.4, 95% CI, 3.2-9.1). Low levels of lactate in AF (<10.1 mmol/l) were associated with an increased probability of spontaneous vaginal delivery (adjusted OR, 2.7, 95% CI, 1.7-4.8). CONCLUSION The partogram together with the concentration of lactate in AF is a better predictor of operative intervention in dysfunctional labor than the partogram alone.

Association Between Adverse Neonatal Outcome and Lactate Concentration in Amniotic Fluid

OBJECTIVE: To estimate whether a high lactate concentration in amniotic fluid, together with cardiotocography, can be used as an indicator for an increased risk of adverse neonatal outcome at delivery. METHOD: A prospective cohort study was performed at two tertiary center labor wards in Sweden. Healthy women with full-term, singleton pregnancies and cephalic presentation in spontaneous active labor were included in the study (N=825). Lactate concentration in samples of amniotic fluid collected in the course of vaginal examinations during labor were correlated with cardiotocography 30 minutes before delivery and a composite score for adverse neonatal outcome. RESULTS: High lactate concentration in amniotic fluid (greater than 10.1 mmol/L) was associated with an adverse neonatal outcome (odds ratio [OR] 4.4, 95% confidence interval [CI] 2.3–8.2). Fetal bradycardia within 30 minutes before delivery was also associated with an increased risk of adverse neonatal outcome (OR 7.4, 95% CI 3.04–18.11). If lactate in amniotic fluid was greater than 10.1 mmol/L and bradycardia was seen together, the risk of delivering a neonate with an adverse neonatal outcome was increased 11-fold (OR 10.7, 95% CI 3.7–31.7). CONCLUSION: High lactate concentration in amniotic fluid and fetal bradycardia during the last 30 minutes before delivery indicate an increased risk of adverse neonatal outcome at delivery. LEVEL OF EVIDENCE: III

Assessment of pain in women randomly allocated to speculum or digital insertion of the Foley catheter for induction of labor

Objective. The primary aim was to assess pain subjectively and objectively in women during insertion of a Foley catheter for induction of labor. A secondary aim was to assess pain during cervical ripening and to evaluate maternal satisfaction. Design. Randomized controlled trial. Setting. University hospital, Sweden. Population. Forty‐two women undergoing induction of labor and cervical ripening with a Foley catheter. Methods. Women were randomly allocated to digital (n=21) or to speculum (n=21) placement of a Foley catheter. A visual analogue scale (VAS) was used for subjective assessment of pain and, for objective measurements, a skin conductance algesimeter was used and the area under the curve (AUC) was calculated (μSs). Maternal satisfaction was evaluated in a questionnaire. Main outcome measures. Pain sensation during placement of the Foley catheter. Results. There was a significant difference between groups in pain measurements during insertion of the Foley catheter. The speculum group had higher median pain scores than the digital group, VAS=5 vs. = 3 (p=0.03) and greater median AUC measurements: 1840 vs. 823μSs (p=0.04). There was no difference in pain assessments during cervical ripening. Overall satisfaction scores were high and comparable between groups. Conclusion. Digital placement of the Foley catheter is subjectively and objectively less painful compared to the use of a speculum. Digital placement should therefore be considered as an alternative in the management of these patients. Ripening of the cervix with the Foley catheter is well tolerated and the overall satisfaction rate among patients induced with this method is high.

Level of lactate in amniotic fluid and its relation to the use of oxytocin and adverse neonatal outcome.

To assess whether the frequency of adverse neonatal outcome at delivery is related to the level of lactate in amniotic fluid and to the use of oxytocin.