Correction: Fetal overgrowth in women with type 1 and type 2 diabetes mellitus.

[This corrects the article DOI: 10.1371/journal.pone.0187917.].

Correlation between maternal and umbilical cord 25-hydroxy-vitamin D levels over a range of values. A prospective observational study from the United Arab Emirates.

Worldwide vitamin D insufficiency is remarkably prevalent in both children and adults, including pregnant women. The total amount of the vitamin is best measured by 25-hydroxy-vitamin D (25(OH)D), which is a measurement of total serum cholecalciferol 25(OH)D3 and ergocalciferol 25(OH)D2. There is a known correlation between maternal and umbilical cord blood (UCB) 25(OH)D; however, whether specific maternal demographics or comorbidities influence the correlation remains uncertain. This prospective observational study was designed to study if maternal 25(OH)D levels, maternal age and BMI, amount of supplementation, mode of delivery, diabetes, hypertension/preeclampsia, or sunlight exposure had an impact on the correlation. Women were enrolled in the study at admission to the labor ward. If they agreed to participate, venous blood was directly collected and analyzed for 25(OH)D. The UCB was sampled after delivery from the unclamped cord and immediately analyzed for 25(OH)D. ANOVA, Fisher's exact test, Pearson's correlation, and test of the differences between correlations using Fisher's z-transformation with Bonferroni correction were used accordingly. Of the 298 women enrolled, blood from both the mother and umbilical cord was analyzed successfully for 25(OH)D in 235 cases. The crude correlation between maternal and UCB 25(OH)D was very strong over all values of 25(OH)D (r = 0.905, R2 = 0.821, p <0,001) and remained strong independently of maternal demographics or co-morbidities (r ≥ 0.803, R2 ≥ 0.644, p <0.001). For women who delivered by caesarean section in second stage the correlation was strong (r ≥ 0.633, R2 ≥ 0.4, p <0.037). Test of differences between correlations showed significant stronger correlation in women with unknown 25(OH)D3 supplementation compared to women receiving 10.000 IU/week (p = 0.02) and 20.000IU/week (p = 0.01) and that the correlation was significantly stronger for women with a BMI of 25-29.9 compared to women with a BMI of <24.9 (p = 0.004) and 30-34.9 (p = 0.002). 213 (91%) women had lower 25(OH)D compared to the neonate, with a mean difference of -13.7nmol/L (SD = 15.6). In summary, the correlation between maternal and UCB 25(OH)D is very strong throughout low to high maternal levels of 25(OH)D with lower levels in maternal blood. Typical maternal demographics and comorbidities did not affect the transition.

Adverse neonatal outcome and veno-arterial differences in umbilical cord blood pH (ΔpH) at birth: a population-based study of 108,629 newborns.

BACKGROUND: Umbilical cord blood gases are routinely used by midwives and obstetricians for quality assurance of birth management and in clinical research. They can form the basis for solving medicolegal issues in the identification of severe intrapartum hypoxia at birth. However, the scientific value of veno-arterial differences in cord blood pH, also known as ΔpH, is largely unknown. By tradition, the Apgar score is frequently used to predict perinatal morbidity and mortality, however significant inter-observer and regional variations decrease its reliability and there is a need to identify more accurate markers of perinatal asphyxia. The aim of our study was to investigate the association of small and large veno-arterial differences in umbilical cord pH, ΔpH, with adverse neonatal outcome. METHODS: This retrospective, population-based study collected obstetric and neonatal data from women giving birth in nine maternity units from Southern Sweden from 1995 to 2015. Data was extracted from the Perinatal South Revision Register, a quality regional health database. Newborns at ≥37 gestational weeks with a complete and validated set of umbilical cord blood samples from both cord artery and vein were included. Outcome measures included: ΔpH percentiles, 'Small ΔpH' (10th percentile), 'Large ΔpH' (90th percentile), Apgar score (0-6), need for continuous positive airway pressure (CPAP) and admission to neonatal intensive care unit (NICU). Relative risks (RR) were calculated with modified Poisson regression model. RESULTS: The study population comprised of 108,629 newborns with complete and validated data. Mean and median ΔpH was 0.08 ± 0.05. Analyses of RR showed that 'Large ΔpH' was associated with a decreased RR of adverse perinatal outcome with increasing UApH (at UApH ≥7.20: RR for low Apgar 0.29, P = 0.01; CPAP 0.55, P = 0.02; NICU admission 0.81, P = 0.01). 'Small ΔpH' was associated with an increased RR for low Apgar score and NICU admission only at higher UApH values (at UApH 7.15-7.199: RR for low Apgar 1.96, P = 0.01; at UApH ≥7.20: RR for low Apgar 1.65, P = 0.00, RR for NICU admission 1.13, P = 0.01). CONCLUSION: Large differences between cord venous and arterial pH (ΔpH) at birth were associated with a lower risk for perinatal morbidity including low 5-minute Apgar Score, the need for continuous positive airway pressure and NICU admission when UApH was above 7.15. Clinically, ΔpH may be a useful tool in the assessment of the newborn's metabolic condition at birth. Our findings may stem from the ability of the placenta to adequately replenish acid-base balance in fetal blood. 'Large ΔpH' may therefore be a marker of effective gas exchange in the placenta during birth.

Glycemic, maternal and neonatal outcomes in women with type 1 diabetes using continuous glucose monitoring during pregnancy - Pump vs multiple daily injections, a secondary analysis of an observational cohort study.

INTRODUCTION: Continuous glucose monitoring (CGM) provides detailed information about glucose level fluctuations over time. The method is increasingly being used in pregnant women with type 1 diabetes. However, only one previous study compared CGM results related to pregnancy outcomes in women using insulin pumps with those administering multiple daily injections (MDI). We performed a secondary analysis of CGM metrics from an observational cohort of pregnant women with type 1 diabetes and compared insulin pump and MDI therapies in relation to maternal and neonatal outcomes. MATERIAL AND METHODS: The study included 185 pregnant Swedish women with type 1 diabetes undergoing CGM throughout pregnancy. Women were divided according to insulin administration mode, ie MDI (n = 131) or pump (n = 54). A total of 91 women used real-time CGM and 94 women used intermittently viewed CGM. Maternal demographics and maternal and neonatal outcome data were collected from medical records. CGM data were analyzed according to predefined glycemic indices: mean glucose; standard deviation; percentage of time within, below and above glucose target range; mean amplitude of glycemic excursion; high and low glucose indices; and coefficient variation in percent. Associations between insulin administration mode and CGM data, on the one hand, and maternal and neonatal outcomes, on the other, were analyzed with analysis of covariance and logistic regression, respectively, adjusted for confounders. RESULTS: There were no differences in maternal characteristics or glycemic indices between the MDI and pump groups, except for a longer duration of type 1 diabetes and higher frequencies of microangiopathy and real-time CGM among pump users. Despite improvement with each trimester, glucose levels remained suboptimal throughout pregnancy in both groups. There were no differences between the MDI and pump groups concerning the respective associations with any of the outcomes. The frequency of large for gestational age was high in both groups (MDI 49% vs pump 63%) and did not differ significantly. CONCLUSIONS: Pregnant women with type 1 diabetes did not differ in glycemic control or pregnancy outcome, related to MDI or pump administration of insulin. Glycemic control remained suboptimal throughout pregnancy, regardless of insulin administration mode.

Maternal arterial blood gas values during delivery: Effect of mode of delivery, maternal characteristics, obstetric interventions and correlation to fetal umbilical cord blood.

INTRODUCTION: Obstetricians routinely use biochemical parameters from non-pregnant women to assess the condition of the laboring mother. However, it is well known that pregnancy leads to significant physiological changes in most organ systems. The aim of this study was to determine normal values for maternal arterial blood gases during vaginal deliveries as compared with control values from planned cesarean sections. We also wanted to elucidate the effect of various maternal characteristics, mode of delivery and obstetric interventions on blood gas values. MATERIAL AND METHODS: We carried out a randomly selected, prospective-observational cohort study of 250 women undergoing vaginal delivery and 58 women undergoing planned cesarean section at the Department of Obstetrics and Gynecology, Skåne University Hospital, Malmö, Sweden. RESULTS: We found significant differences for gestational age, parity, umbilical venous blood pH, pCO2 and lactate values between the two study groups (P < .005). Significantly lower pH, pCO2 , pO2 and sO2 were found in mothers delivering vaginally. Higher base deficit, hemoglobin, bilirubin, potassium, glucose and lactate were found in vaginal deliveries than in planned cesarean sections (P < .02). Maternal body mass index (BMI), smoking and hypertension were not significantly correlated to acid base parameters in women with vaginal deliveries. On the other hand, multiple regression showed significant associations for the use of epidural anesthesia on maternal pH (P < .05) and pO2 (P < .01); and synthetic oxytocin on pCO2 (P = .08), glucose (P < .00) and lactate (P < .02) levels in maternal arterial blood. Maternal arterial pH, pCO2 and lactate values correlated significantly to values in venous umbilical cord blood (P < .000). CONCLUSIONS: Maternal arterial blood gas parameters varied significantly according to mode of delivery, the use of epidural anesthesia and synthetic oxytocin.

Effectiveness of fetal scalp stimulation test in assessing fetal wellbeing during labor, a retrospective cohort study.

BACKGROUND: It is discussed whether fetal scalp stimulation (FSS) test is a reliable complimentary tool to cardiotocography (CTG) to assess fetal wellbeing during labor. The test is based on the assumption that a well-oxygenated fetus, in contrast to the depressed fetus, will respond to a certain stimulus. The aim of this study was to investigate the effectiveness of the FSS-test. METHODS: A retrospective observational study carried out Copenhagen University Hospital, Herlev, Denmark. Laboring women with singleton pregnancies in cephalic presentation after gestation week 33 and indication for fetal blood sampling (FBS) were eligible for inclusion. The FSS-test was classified as positive when an acceleration was absent at the time of FBS and negative when an acceleration was present. Lactate in scalp blood was measured by the point-of-care device LactatePro™ and pH in artery umbilical cord blood by the stationary blood gas analyzer ABL800. Lactate level < 4.2 mmol/L in scalp blood and arterial cord pH > 7.1 were cut-offs for normality. RESULTS: Three hundred eighty-five women were included. The cohort was divided by the FBS-to-delivery time: Group 1 (n = 128) ≤ 20 min, Group 2 (n = 117) 21-59 min and Group 3 (n = 140) ≥ 60 min. The proportion of FSS-positive tests differed significantly between the groups (p < 0.000). In Group 1 the sensitivity, specificity and likelihoods for scalp lactate ≥4.2 mmol/L were 81.5 (95% CI 67-90.1), 13.3 18.5 (95% CI 5.9-24.6), LHR+ 0.94 (95% CI 0.8-1.1) and LHR - 1.4 (95% CI 0.6-3.2) and for umbilical artery pH ≤ 7.10 the values were 82.6% (95% CI 61.2-95.1), 16% (95% CI 9.4-24.7), 1.0 (95% CI 0.8-1.2) and 1.1 (95% CI 0.4-3) respectively. Regardless of the FBS-to-delivery time the LHR+ for lactate ≥4.2 mmol/L increased to 1.38 (95% CI 1.2-1.6). CONCLUSION: The effectiveness of scalp stimulation test was poor for both ruling in and out fetal hypoxia during labor. Absence of a provoked acceleration seems to be a normal phenomenon in the second stage of labor.

Reliability of the point-of care analyzer "StatStrip® Xpress™" for measurement of fetal blood lactate.

OBJECTIVES: Measurement of lactate in fetal blood is used to assess the degree of anaerobic metabolism. The technical difficulties in obtaining enough scalp blood for analysis by a bloodgas-analyzer advocates for the use of a point-of-care device. StatStrip®Xpress™ (SSX) has shown promising properties but needs further evaluation before implementation into fetal surveillance. METHODS: Arterial/venous umbilical cord blood from 112 newborns were analyzed simultaneously with SSX and the reference method ABL800™. From 321 fetuses with abnormal heart rate scalp blood was sampled and analyzed repeatedly with SSX. RESULTS: ABL800™ -lactate ranged from 1.9-13.3 mmol/L in arterial to 1.5-10.2 mmol/L in venous cord blood with excellent correlation to SSX (R2 = 0.95). SSX-values were lower compared to the reference method ranging from -0.79 mmol/L for low values to -1.68 mmol/L for high values. The mean CV for SSX-values in cord respectively scalp blood was: lactate ≤3 mmol/L 7.1% respectively 8.4%; lactate >3 mmol/L 3.8% respectively 6.8%. Repeated measurements of the same sample with SSX where without significant difference in cord/scalp blood (p = 0.11). CONCLUSION: SSX-lactate values were constantly lower but correlated excellent to the reference method. The reproducibility was good for cord and scalp blood. We suggest SSX as an attractive device for measurement of fetal lactate.

Continuous glucose monitoring in pregnant women with type 1 diabetes: an observational cohort study of 186 pregnancies.

AIMS/HYPOTHESIS: The aim of this study was to analyse patterns of continuous glucose monitoring (CGM) data for associations with large for gestational age (LGA) infants and an adverse neonatal composite outcome (NCO) in pregnancies in women with type 1 diabetes. METHODS: This was an observational cohort study of 186 pregnant women with type 1 diabetes in Sweden. The interstitial glucose readings from 92 real-time (rt) CGM and 94 intermittently viewed (i) CGM devices were used to calculate mean glucose, SD, CV%, time spent in target range (3.5-7.8 mmol/l), mean amplitude of glucose excursions and also high and low blood glucose indices (HBGI and LBGI, respectively). Electronic records provided information on maternal demographics and neonatal outcomes. Associations between CGM indices and neonatal outcomes were analysed by stepwise logistic regression analysis adjusted for confounders. RESULTS: The number of infants born LGA was similar in rtCGM and iCGM users (52% vs 53%). In the combined group, elevated mean glucose levels in the second and the third trimester were significantly associated with LGA (OR 1.53, 95% CI 1.12, 2.08, and OR 1.57, 95% CI 1.12, 2.19, respectively). Furthermore, a high percentage of time in target in the second and the third trimester was associated with lower risk of LGA (OR 0.96, 95% CI 0.94, 0.99 and OR 0.97, 95% CI 0.95, 1.00, respectively). The same associations were found for mean glucose and for time in target and the risk of NCO in all trimesters. SD was significantly associated with LGA in the second trimester and with NCO in the third trimester. Glucose patterns did not differ between rtCGM and iCGM users except that rtCGM users had lower LBGI and spent less time below target. CONCLUSIONS/INTERPRETATION: Higher mean glucose levels, higher SD and less time in target range were associated with increased risk of LGA and NCO. Despite the use of CGM throughout pregnancy, the day-to-day glucose control was not optimal and the incidence of LGA remained high.

Arterio-venous blood gas Δvalues for validation of umbilical cord blood samples at birth are not only biased by sample mix ups but also affected by clinical factors.

INTRODUCTION: Traditional validation of umbilical cord blood samples with positive veno-arterial ΔpH and arterio-venous ΔpCO2 values confirms the source of samples, whereas negative Δvalues represent mix-up of samples. To investigate whether this is true, the distributions of V-A ΔpO2 and A-V Δlactate were also explored and related to clinical characteristics. In addition, different cord blood sampling techniques were evaluated. MATERIAL AND METHODS: Register study with cord blood acid-base and clinical data from 27 233 newborns. Clinical characteristics were related to positive, zero and negative Δvalues. Blood samplings from unclamped and double-clamped cords were compared. A two-sided P < 0.05 was considered significant. RESULTS: ΔpH and ΔpCO2 values distributed into positive, around zero, and negative sub-populations, with significant differences in pH and clinical characteristics between sub-populations. No such sub-populations were distinguished for ΔpO2 and Δlactate. The 2.5th and 5th ΔpH percentiles were 0.013 and 0.022, respectively, and for ΔpCO2 0.30 and 0.53 kPa. Applying 5th percentile criteria resulted in 3.5% of "approved" cases showing a ΔpO2  ≤ 0. Puncture and sampling of the unclamped cord resulted in significantly better sample quality. CONCLUSIONS: Unphysiological negative ΔpO2 values occurred despite correct validation with traditional criteria. Δlactate cannot be used for validation because both positive and negative values are physiological. Positive/around zero/negative ΔpH and ΔpCO2 sub-populations were associated with significant differences in pH and clinical characteristics, indicating that defective sampling and sample handling are not the sole explanations for negative Δvalues. Prompt puncture and sampling of the unclamped cord resulted in best sample quality.

Infant outcome at four years of age after intrapartum sampling of scalp blood lactate for fetal assessment. A cohort study.

OBJECTIVE: To correlate the value of lactate in fetal scalp blood at delivery and the outcomes of the offspring at four years of age. METHODS: Cases where scalp blood lactate was taken within sixty minutes before delivery were identified from the randomized trial "Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress". Data were grouped according to the generally accepted cutoffs for normality, pre-acidemia, acidemia and concentrations above mean +2 SD during the second stage. The outcome measures included gross-/fine motor function, vision, hearing, speaking and cognitive disorders, signs of central motor damage and referral to specialized pediatric services. RESULTS: 307 cases were available for final analyse. With normal scalp lactate concentration, the number of children with a diagnosed disorder was lower compared to the pre-acidemic/acidemic groups, although the findings were only significant for fine motor dysfunction (p = 0.036). Elevated lactate values were significantly associated with increased risk for a poorer capacity of attention and understanding of instructions (OR 1.37, 95% CI 1.07-1.74), and for fine motor dysfunction (OR 1.22, 95% CI 1.00-1.49) at the age of four. CONCLUSION: Higher levels of lactate in fetal scalp blood seems to be associated with increased risk of an aberrant developmental outcome at four years of age in some areas.

Fetal overgrowth in women with type 1 and type 2 diabetes mellitus.

OBJECTIVES: Despite improved glycemic control, the rate of large-for-gestational-age (LGA) infants remains high in pregnancies complicated by diabetes mellitus type 1 (T1DM) and type 2 (T2DM). Poor glycemic control, obesity, and excessive gestational weight gain are the main risk factors. The aim of this study was to determine the relative contribution of these risk factors for LGA in women with T1DM and T2DM, after controlling for important confounders such as age, smoking, and parity. METHODS: In this retrospective chart review study, we analyzed the medical files of pregnant women with T1DM and T2DM who attended the antenatal care program at Skåne University Hospital during the years 2006 to 2016. HbA1c was used as a measure of glycemic control. Maternal weight in early pregnancy and at term was registered. LGA was defined as birth weight > 2 standard deviations of the mean. Univariable and multivariable logistic regression analysis was used to calculate odds ratios (OR's) and 95% confidence intervals (CIs) for LGA. RESULTS: Over the 11-year period, we identified 308 singleton pregnancies in 221 women with T1DM and in 87 women with T2DM. The rate of LGA was 50% in women with T1DM and 23% in women with T2DM. The multivariable regression model identified gestational weight gain and second-trimester HbA1c as risk factors for LGA in T1DM pregnancies (OR = 1.107, 95% CI: 1.044-1.17, and OR = 1.047, 95% CI: 1.015-1.080, respectively) and gestational weight gain as a risk factor in T2DM pregnancies (OR = 1.175, 95% CI: 1.048-1.318), independent of body mass index. CONCLUSIONS: Gestational weight gain was associated with LGA in women with T1DM and T2DM, independent of maternal body mass index. The findings suggest that monitoring and regulation of gestational weight gain is important in the clinical care of these women, to minimize the risk of fetal overgrowth.

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.

Fetal scalp blood sampling during labor: an appraisal of the physiological basis and scientific evidence.

Fetal cardiotocography is characterized by low specificity; therefore, in an attempt to ensure fetal well-being, fetal scalp blood sampling has been recommended by most obstetric societies in the case of a non-reassuring cardiotocography. The scientific agreement on the evidence for using fetal scalp blood sampling to decrease the rate of operative delivery for fetal distress is ambiguous. Based on the same studies, a Cochrane review states that fetal scalp blood sampling increases the rate of instrumental delivery while decreasing neonatal acidosis, whereas the National Institute of Health and Clinical Excellence guideline considers that fetal scalp blood sampling decreases instrumental delivery without differences in other outcome variables. The fetal scalp is supplied by vessels outside the skull below the level of the cranial vault, which is likely to be compressed during contractions. The self-regulated redistribution of oxygenated blood from peripheral to central organs causes peripheral ischemia, thus theoretically bringing into question the scalp capillary bed as representative of the central circulation.

An overlooked aspect on metabolic acidosis at birth: blood gas analyzers calculate base deficit differently.

OBJECTIVE: Metabolic acidosis (MA) at birth is commonly defined as umbilical cord arterial pH < 7.0 plus base deficit (BD) ≥ 12.0 mmol/L. Base deficit is not a measured entity but is calculated from pH and Pco(2) values, with the hemoglobin (Hb) concentration [Hb] included in the calculation algorithm as a fixed or measured value. Various blood gas analyzers use different algorithms, indicating variations in the MA diagnosis. The objective was therefore to calculate the prevalence of MA in blood and extracellular fluid with algorithms from three blood gas analyzer brands relative to the Clinical and Laboratory Standards Institute (CLSI) algorithm. DESIGN: Comparative study. SETTING: University hospital. SAMPLE: Arterial cord blood from 15 354 newborns. MAIN OUTCOME MEASURE: Prevalence of MA. METHODS: Blood was analyzed in a Radiometer ABL 735 analyzer. Base deficit was calculated post hoc with algorithms from CLSI and Corning and Roche blood gas analyzers, and with measured and fixed (9.3 mmol/L) values of [Hb]. RESULTS: The prevalence of BD ≥12.0 mmol/L in blood was with the CLSI algorithm 1.97%, Radiometer 5.18%, Corning 3.84% and Roche 3.29% (CLSI vs. other; McNemar test, p < 0.000001). Likewise, MA prevalences were 0.58, 0.66, 0.64 and 0.64%, respectively (p≤ 0.02). Base deficit ≥ 12.0 mmol/L and MA rates were lower in extracellular fluid than in blood (p≤ 0.002). Algorithms with measured or fixed Hb concentration made no differences to MA rates (p≥ 0.1). CONCLUSIONS: The neonatal metabolic acidosis rate varied significantly with blood gas analyzer brand and fetal fluid compartment for calculation of BD.

How mathematics warp biology: round-off of umbilical cord blood gas case value decimals distorts calculation of metabolic acidosis at birth.

OBJECTIVE: To illustrate the impact on settling neonatal metabolic acidosis diagnosis by rounding off pH and base deficit (BD) case value decimals. DESIGN: Comparative study. SETTING: University maternity units. SAMPLE: Umbilical cord arterial blood gas values from 18 831 newborns. MAIN OUTCOME MEASURES: Prevalences of pH <7.05 and metabolic acidosis diagnosis (pH <7.05 plus BD >12.0 mmol/L). METHODS: Calculation of BD from pH and pCO(2) values, and calculating the prevalences of metabolic acidosis before and after rounding off three-decimal values to two or one decimals. The 'round to half even' and 'round half up' round-off rules were used for digit 5. RESULTS: Arterial pH was ≤7.049 in 339 newborns (1.8%). In 27 (8.0%) pH was 7.045-7.049, rounded off to 7.05 when truncated to two decimals (crude vs. round-off values; McNemar's test, p<0.000001). Depending on round-offs of pH case value decimals before or after calculation of BD, and round-offs of resulting three-decimal BD values to one decimal, metabolic acidosis 'disappeared' or 'appeared' in eight of 75 metabolic acidosis cases (10.7%). With different modes of calculation, the number of metabolic acidosis cases varied between 75 and 71 cases (p≥0.1). CONCLUSION: Due to pH and BD case value decimal round-offs, a diagnostic discrepancy of acidotic pH values occurred in 8%, and of metabolic acidosis diagnosis in 10.7% of cases. A drift of a dichotomy parameter value cut-off due to decimal round-offs will result in a shift in distribution of positive and negative cases in a population sample.

Relation between umbilical cord blood pH, base deficit, lactate, 5-minute Apgar score and development of hypoxic ischemic encephalopathy.

OBJECTIVE: Umbilical cord acid-base analysis is fundamental for assessing intrapartum hypoxia. The accuracy of arterial umbilical cord blood lactate, pH and base deficit to reflect a low 5-minute Apgar score and hypoxic ischemic encephalopathy (HIE) stage 2-3 was assessed, and new gestational age-adjusted reference standards were compared with traditional stationary reference values. DESIGN AND SAMPLE: A total of 13,735 pH-validated routine cord acid-base values from singleton deliveries were tested with stationary and gestational age-adjusted reference values using receiver operating characteristic curves and calculation of area under curve. SETTING: University hospital. MAIN OUTCOME MEASURES: Accuracy of low pH, high base deficit and high lactate, alone or in combination, to imply 5-minute Apgar score < 7 or < 4 or HIE. RESULTS: Gestational age-adjusted values were for all parameters significantly better than crude values to indicate Apgar score < 7. For Apgar score < 4, the differences were not significant. The frequency of HIE was 0.046%, making statistical analyses pointless. Gestational age-adjusted lactate had the overall best accuracy and among combinations; a low age-adjusted pH plus high age-adjusted lactate was slightly better than a low age-adjusted pH plus high age-adjusted base deficit. The sensitivity and positive predictive value were low for all parameters. CONCLUSIONS: Lactate in cord arterial blood at birth is at least as good as base deficit to reflect an impaired condition at birth, and best when gestational age-adjusted values are used. Due to methodological confounding involved in calculation of base deficit, lactate may replace base deficit as an acid-base outcome parameter at birth.

Base deficit estimation in umbilical cord blood is influenced by gestational age, choice of fetal fluid compartment, and algorithm for calculation.

OBJECTIVE: The purpose of this study was to explore the influences of gestational age, the choice of fetal fluid compartment, and the algorithm for calculation on the estimation of the base deficit in umbilical cord arterial blood at birth. STUDY DESIGN: From 1995 to 2002, cord arterial blood gases and obstetric data were available for 43,551 newborn infants at 37+ weeks of gestation (cohort I). The mean base deficit in blood and the base deficit in extracellular fluid were estimated from pH and PCO2 values in 28,213 newborn infants with a 5-minute Apgar score of > or = 9 (cohort II) with the use of 3 different calculation algorithms (base deficit in blood, base deficit in extracellular fluid [A], and base deficit in extracellular fluid [B]). RESULTS: In cohort II, the base deficit in blood, the base deficit in extracellular fluid (A), and the base deficit in extracellular fluid (B) increased with advancing gestational age (linear regression; P < .0001). The curves run almost parallel, with the base deficit in blood being higher than the base deficit in extracellular fluid (A) and (B). With the use of receiver operating characteristic curves in cohort I, the area under curve to indicate a 5-minute Apgar score of < 7 and < 4 showed the area under curve-pH to be greater than the area under curve-base deficit in extracellular fluid (A) and (B), the area under curve-base deficit in blood to be greater than the area under curve-base deficit in extracellular fluid (A) and (B) for a 5-minute Apgar score of < 7, and the area under curve-base deficit in blood to be greater than the area under curve-base deficit in extracellular fluid (A) and (B) for an Apgar score of < 4. The cutoffs with highest sensitivity and lowest false-positive rate for a 5-minute Apgar score of < 7 and < 4 were, for both scores, a pH value of 7.15, a base deficit in blood of 10 mmol/L, a base deficit in extracellular fluid (A) of 8 mmol/L, and a base deficit in extracellular fluid (B) of 6 mmol/L. CONCLUSION: The calculated values of the base deficit in umbilical cord arterial blood are influenced decisively by gestational age, the choice of fetal fluid compartment, and the calculation algorithms that are used. The power of the base deficit to indicate neonatal distress depends on the choices of fluid compartment and the algorithm that is used to calculate the base deficit.

Physiological development of a mixed metabolic and respiratory umbilical cord blood acidemia with advancing gestational age.

OBJECTIVE: To investigate respiratory and metabolic components of gestational age-dependent umbilical cord blood gas changes. STUDY DESIGN: Cord blood gases were determined in 1336 vigorous singletons with uncomplicated cephalic vaginal delivery at 37-43 weeks. Linear regression analysis and non-parametric statistics were used with a P < 0.05 being significant. RESULTS: Gestational age correlated negatively with arterial pH and HCO3- and positively with pCO2 and base deficit. Venous blood showed corresponding changes except for pCO2, which was independent of gestational age. Arterial pCO2, but not venous, correlated positively with birthweight deviation from the mean. The fractional fetal CO2 production per birthweight unit and the fractional placental CO2 clearance per placental weight unit were not correlated with gestational age. CONCLUSIONS: A mixed respiratory and metabolic cord blood acidemia develops with advancing gestational age. The respiratory component depends on an increased 'CO2 load' from the growing fetus and not on deterioration of placental gas exchange. The etiology of the metabolic component is yet unknown.

[Quality control of ultrasound weight estimation in a central hospital]. / Kvalitetskontrol af vaegtscanning med ultralyd på et centralsygehus.

INTRODUCTION: The aim of the study was to carry out a quality control of fetal weight estimated by ultrasonography in an obstetric ward of a district hospital. MATERIALS AND METHODS: The study comprised 105 scannings. The weight estimates were projected to the date of birth, and the difference in percentage between the actual birth weight and the projected weight was estimated. RESULTS: There was a good agreement between the projected weight and the actual birth weight (r = 0.87). The mean value was -2.5%, and the standard deviation in the difference between the projected weight estimates and the actual birth weight, was 11%, which was consistent with findings in other studies. DISCUSSION: Ongoing quality control of weight estimates and establishment of obstetric databases are recommended.