Persistence of the fetal pattern in late preterm newborns

Abstract

INTRODUCTION: Hypoglycemia is a common clinical problem in premature newborns, there are currently controversies about what are the normal values for its optimal management. According to a study

Entitled Glucose in Well Babies (GLOW), transient neonatal hypoglycemia is composed of 2 distinct phases: the initial phase between birth and 48 hours represents hypoglycemia due to the persistence of the fetal pattern of hyperinsulinism and the second phase of 48 at 96 hours it instead represents a mild fasting state ketonemia, reflecting resolution of hyperinsulinism where it likely reflects limited nutrients in these breastfed infants. Due to the fact that hypoglycemia is frequent in premature infants, requiring exhaustive controls of it and in many cases invasions for its treatment, it would be important to know if the results determined by the GLOW study can be transposed to late preterm infants (35-36 weeks). gestational) OBJECTIVES: To assess plasma glucose and beta-hydroxybutyrate (BOHB) concentrations in late preterm infants during the first 48 hours of life. Secondary: Compare glycemic values in children according to mode of birth, sex and evaluate differences in glycemic concentrations according to type of feeding.

MATERIALS AND METHODS: Observational, prospective and analytical study. Newborns between 34 to 36 weeks by vaginal delivery or cesarean section are included, with an Apgar score greater than 7 in their

first minute of life and weight in the 10-90th percentile for gestational age. The following variables were analyzed at birth: sex, weight, gestational age, maternal and fetal pathology during the first 48 hours of life, and preprandial glycemia and ketonemia values, together with the type of feeding. Statistical analysis: The categorical variables were analyzed by describing their percentages and the number of patients observed. For continuous variables, the means and medians were obtained as measures of centrality, and standard deviations and interquartile range as measures of data dispersion. Since the data did not present a normal distribution, non-parametric Kruskal-Wallis tests and Spearman's correlations were applied.

RESULTS: The sample consisted of 20 patients, 12 men and 8 women. Median (interquartile range, ICI)

gestational age was 36 (34-36) weeks, median (ICI) birth weight was 258 (1250-3320) g. Thirteen patients were born by caesarean section and 7 by vaginal delivery. During the study, 10 (50%) of the patients received breast milk as the only source of nutrition, while the same percentage of patients received breast milk plus supplement. At birth, the observed APGAR value was 9 – 9 ICC [8.00-10.0].

In relation to BOHB levels, it was found that patients exclusively fed with breast milk had significantly higher levels of ketone bodies compared to those who received another type of feeding ICC 0.5 [0.2- 0.7]. Patients exclusively breastfed had significantly lower blood glucose levels compared with those who received another form of ICC 68 feeding [48-117]. No significant effects were found in relation to sex, form of birth or the time analyzed in the levels of ketonemia or glycemia.

CONCLUSION: it was observed that both sex and the form of birth do not significantly influence blood glucose and ketonemia levels in preterm newborns. On the other hand, after birth, glucose levels and ketone bodies remain relatively stable during the first 48 hours. Regarding the way of feeding, exclusive breast milk leads to lower glycemia values than those observed in formula-fed newborns.