Lactate in cord blood and its relation to fetal gluconeogenesis in at term deliveries

Neonatal hypoglycaemia

Low blood concentrations of glucose (hypoglycaemia) soon after birth are common because of the delayed metabolic transition from maternal to endogenous neonatal sources of glucose. Because glucose is the main energy source for the brain, severe hypoglycaemia can cause neuroglycopenia (inadequate supply of glucose to the brain) and, if severe, permanent brain injury. Routine screening of infants at risk and treatment when hypoglycaemia is detected are therefore widely recommended. Robust evidence to support most aspects of management is lacking, however, including the appropriate threshold for diagnosis and optimal monitoring. Treatment is usually initially more feeding, with buccal dextrose gel, followed by intravenous dextrose. In infants at risk, developmental outcomes after mild hypoglycaemia seem to be worse than in those who do not develop hypoglycaemia, but the reasons for these observations are uncertain. Here, the current understanding of the pathophysiology of neonatal hypoglycaemia and recent evidence regarding its diagnosis, management, and outcomes are reviewed. Recommendations are made for further research priorities.

Amino Acid Composition of Amniotic Fluid during the Perinatal Period Reflects Mother's Fat and Carbohydrate Intake

Dietary content during pregnancy is important because it is necessary for the growth of the fetus. With the assumption that the nutritional status of the fetus can be monitored by measuring amino acid concentrations in the amniotic fluid, we investigated whether the habitual dietary intake of pregnant women affected the composition of the amniotic fluid and the significance of performing amniotic fluid analysis. The subjects were 34 mothers who delivered full-term babies by cesarean section. Three biological samples were collected from the mothers: blood, cord blood, and amniotic fluid. At the same time, the mothers' prenatal nutritional intake information was also recorded. When the amino acid contents of the samples were compared with the mothers' nutrient intake, many amino acids in the amniotic fluid were positively correlated with lipid intake, but not with protein intake. There was a negative correlation between lipid intake and carbohydrate intake, and the amino acid contents of the amniotic fluid were also negatively correlated with carbohydrate intake. The results of this study were consistent with those found in animal models, suggesting that the analysis of amniotic fluid may be a useful method to investigate the effects of habitual diet during human pregnancy on the fetus.

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.

Venous blood gas parameters in healthy Mediterranean buffalo calves in the first 72 hours of life

In the first hours after calving the neonate radically modifies its anatomy and physiology to adapt to extrauterine life. These modifications, however, make the calf prone to respiratory and metabolic dysfunction. Thus, stillbirth, defined as the death of the neonate within 48 h after birth, represents a relevant issue for buffalo farming. Of the clinical procedures, the blood gas analysis of venous samples provides useful information regarding the acid-base status of the neonate, allowing the optimal management of potential illness calves. However, the blood gas parameters have never been studied in the buffalo calf in the first 72 h of life. Thus, this study aimed to report blood gas parameters at calving and 1, 12, 24, and 72 h after birth in healthy buffalo neonates born after normal parturition. The study involved 20 healthy buffalo calves, born from normal pregnancy and parturition. The parturition and the first hours after were monitored by closed-circuit television cameras, and within 1 min after calving the buffalo neonate received a clinical evaluation (APGAR, temperature), venous blood sampling for blood gas (pH, partial pressure carbon dioxide - pCO₂, partial pressure oxygen - pO₂, base excess, bicarbonate concentration, oxygen saturation, total carbon dioxide - tCO₂, and lactate), and glycemia analysis. The same evaluations were performed after 1, 12, 24, and 72 h. The present study showed a moderate mixed acidosis at calving, similar to that reported in the bovine neonate, likely due to the high venous blood pCO₂ and lactate. This acidemia resolved spontaneously within 12 h as a reduction of pCO₂ (P ≤ 0.05). Lactate reduced significantly (P ≤ 0.05) only at 72 h, similarly to the trend reported previously for the bovine calf. Blood lactate concentration was correlated with glycemia at calving and 1 h (r = 0.677, P = 0.014), and with stage 2 duration (r = 0.647, P = 0.006). These findings support a possible mechanism of glucose generation induced by catecholamines coupled to anaerobic metabolism soon after calving. After calving, all the blood gas parameters changed rapidly reaching values comparable with those reported in the literature for older buffalo calves from 72 h after calving. No correlations were found between APGAR score and venous blood gas parameters, likely due to the inclusion criteria that selected only health buffalo calves born after normal parturition. The findings suggested that the venous blood gas analysis could be considered supportive rather than an alternative to the clinical evaluation of the buffalo calf.

Dietary supplementation with garcinol during late gestation and lactation facilitates acid-base balance and improves the performance of sows and newborn piglets1

The present study was conducted to evaluate the effects of dietary garcinol supplementation during late gestation (from the 90th day of pregnancy; day 90) and lactation on the acid-base balance of the umbilical cord blood and performance of sows and piglets. Sixty sows (Duroc × Yorkshire × Landrace; second- or third-parity; n = 20) were randomly divided into 3 gestation (day 90 of pregnancy) or lactation treatments, control diet (CON; basal diet), basal diet with 200 mg garcinol, and basal diet with 600 mg garcinol per kg of feed. The body weight (BW); backfat thickness and litter size of the sows; and birth weight, weaning weight, and mortality of piglets were recorded. Sows' blood and piglets' umbilical cord blood were collected for the measurements of hematological parameters and antioxidative and immune indexes, and acid-base balance parameters, respectively. The colostrum and milk and fecal samples of the sows were also collected for analysis of milk composition and apparent total tract nutrient digestibility. Garcinol had no effect on the BW and backfat thickness of the sows but significantly increased the birth weight and weaning weight of piglets (P < 0.05) and decreased the mortality (P < 0.05). Moreover, the white blood cell counts and neutrophil count, mean cell hemoglobin, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activity in the plasma of the sows were increased more significantly (P < 0.05) in the garcinol groups than that in the CON group, whereas the malondialdehyde (MDA) content was decreased (P < 0.05). The garcinol treatment significantly increased the pH, HCO3- and base excess values (P < 0.05), whereas it decreased the pCO2 and lactate content (P < 0.05) in the umbilical blood. Dry matter (DM), ash, and ether extract in the colostrum were similar between groups (P > 0.05), whereas the garcinol significantly increased the crude protein (CP) in the milk. In addition, the content of immunoglobulin A (IgA) and immunoglobulin G (IgG) in the plasma of piglets and in colostrum and milk of sows were increased more significantly (P < 0.05) in the garcinol groups than that in the CON group. The apparent total tract nutrient digestibility was similar between treatments. Collectively, this study indicates that sows fed with garcinol in late gestation and lactation showed improved maternal health and antioxidative status, milk protein content, acid-base balance in the umbilical cord blood, and growth performance in piglets, showing promise in natural plant extract nutrition for sows.

The Successful Immediate Neonatal Transition to Extrauterine Life

Purpose:

To define and describe the processes underlying the successful neonatal transition to extrauterine life and methods to assess the transition.

Method:

Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Web of Science, and Google Scholar were searched using a combination of the key words neonate, neonatal, newborn, transition, respiratory OR pulmonary, cardiac, metabolic, pH, umbilical cord, and assessment. Articles in English and German were reviewed. The final sample of articles consisted of one randomized controlled trial, 30 observational studies using human neonates, one observational study using rabbit pups, one secondary analysis, three systematic reviews, and 23 review articles.

Major Findings:

The pertinent findings in regard to normal events in the respiratory, cardiovascular, and metabolic transitions are reviewed and summarized. We address the underlying factors necessary for the transition to extrauterine life, specify the consequences of a successful transition, and review common assessment approaches.

Conclusion:

Available evidence indicates that the successful immediate transition to extrauterine life should be completed within 1–3 hr after birth, though some adaptive processes can fail as late as 24–48 hr after birth. Further research is necessary to identify a feasible, easily used, noninvasive method to assess the status of a neonate’s transition to extrauterine life.