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

Abstract

<b><i>Introduction:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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 (<i>r</i> = −0.77, <i>p</i> < 0.001) and positively correlated with BD (<i>r</i> = 0.63, <i>p</i> < 0.001). Lactate values changed significantly across gestational age (Kruskal-Wallis test, <i>p</i> < 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, <i>p</i> < 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. <b><i>Discussion:</i></b> 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.

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

“…As expected, the data from this large prospectively collected birth register similar to earlier studies, showed that UA lactate concentrations were significantly higher in those newborns who were born by SVD compared to those who were born by ECD. 12,15 We were the first to show that high lactate levels in UA samples correlated independently in multivariable analysis with a longer duration of the active second stage of labor and of ROM, but also with maternal shortness, null parity, maternal infection and higher gestational age at birth. Our results provide new and valuable information about the normal birth process, even though we cannot totally exclude the presence of subclinical or transient birth asphyxia in our dataset.…”

“…previous studies, the duration of the active second stage of labor was the strong effector to the high lactate levels, 10,13 but we also confirmed the previously reported significant association between higher gestational age and increased umbilical lactate levels. 14,15,18 In addition, there were many other clinically significant factors in the analysis, which were related to high UA lactate levels. Some of these, such as first delivery and short stature of the mother, have been considered previously as important risk factors for high fetal or umbilical lactate levels, 16,19 but the duration of maternal intrapartum infection, and infertility are less-studied clinical variables in this context.…”

“…There is some evidence that fetal or umbilical lactate levels also correlate with the maternal parity, gestational age, mode of delivery, and the duration of the active second stage of labor. [12][13][14][15][16] However, no earlier studies exist on the significance of the duration of rupture of membranes (ROM), maternal intrapartum infection, or infertility in umbilical blood lactate levels, and studies on the simultaneous relationships of the maternal and obstetric factors to the umbilical blood lactate levels are sparse.…”

Novel investigations in retinoic-acid-induced cleft palate about the gut microbiome of pregnant mice

“…That might the path that affected the whole body. A retrospective observational study showed that various peripartal risk factors (e.g., uterine rupture, placental abruption, chorioamnionitis, and pre-eclampsia) might have contributed to higher lactate values and that lactate levels in maternal cord blood were associated with a mixed metabolic acidosis in the fetus after birth ( Gaertner et al., 2021 ). Also, maternal lactate and umbilical arterial and venous lactate concentrations were significantly higher in intrauterine growth-retarded infants compared with normal infants ( Marconi et al., 1990 ).…”

Glucose-to-lactate ratio and neurodevelopment in infants with hypoxic-ischemic encephalopathy: an observational study

“…Lactate concentrations were grouped by umbilical arterial reference centiles for healthy term infants, with 1.0, 1.7, 7.2, and 9.0 mmol/L representing the 3rd, 10th, 90th, and 97th centile [ 13 , 14 ].…”