The effects of delivery route and anesthesia type on early postnatal weight loss in newborns: the role of vasoactive hormones

Copeptin Concentrations in Plasma of Healthy Neonates in Relation to Water–Electrolyte Homeostasis in the Early Adaptation Period

Copeptin (CTproAVP) is a stable by-product of arginine–vasopressin synthesis and reflects its secretion by the pituitary gland, considered as a potential new marker of dehydration. The objective of the study was to investigate CTproAVP measured after the first 48 h of postnatal life in relation to serum effective osmolality, urine osmolality, and vessels filling according to the following variables: delivery mode, postnatal weight loss, fluids administered intravenously to the mother, and fluids given orally to the neonate. A prospective observational study was conducted with 200 healthy term infants (53% male) enrolled. Serum CTproAVP concentrations were measured using the ELISA kit; haematocrit, urine osmolality, serum effective osmolality were assessed after 48 h of life. Sonographic measurements of inferior vena cava (IVC) and aorta (Ao) were performed and IVC/Ao ratios were calculated. No correlations were found between CTproAVP concentrations and both serum effective osmolality and urine osmolality. There was also no association between CTproAVP concentrations and vessel filling represented by IVC/Ao index at 48 h of life.

The healthy newborn hydration model: a new model for understanding newborn hydration immediately after birth

The normal small volume of breast milk produced in the first 2 days following birth may raise concerns about adequate hydration in breast-fed newborns. These concerns are further magnified when breast-fed infants lose ≥7% of their birth weight within 2 days postnatally. Weight loss following birth is presumably mostly water loss that could result in hypohydration and subsequent hypernatremic dehydration. However, excess fluid loss immediately following birth is a normal and necessary process. Furthermore, newborns exposed to excess fluid intake during labor may need to lose ≥7% of birth weight in the first 2 days following birth in order to achieve euhydration. Normal newborn fluid loss following birth confounds the use of weight loss as the sole measure of newborn hydration. We thus propose the healthy newborn hydration model that highlights the normalcy of newborn weight loss immediately following birth and the healthy newborn's compensatory mechanisms for preserving adequate hydration. We also recommend the use of serum sodium to measure intravascular osmolarity in addition to monitoring weight loss to obtain a more comprehensive newborn hydration assessment. Research is necessary in healthy newborns to identify relationships among fluids received in utero, newborn weight loss, and hydration, as evaluated with laboratory measures, in the first 2 days following birth. This information will guide clinicians in correctly identifying newborns with inadequate hydration who are in need of supplementary fluids versus newborns with adequate hydration for whom exclusive breast-feeding can be supported and encouraged.

Copeptin and MR-proADM in umbilical cord plasma reflect perinatal stress in neonates born to mothers with diabetes and MR-proANP reflects maternal diabetes

AIM

To examine concentrations of three cardiovascular propeptides in umbilical cord plasma of neonates born to mothers with Type 1, Type 2 and gestational diabetes. Measurement of cardiovascular markers in umbilical cord plasma may potentially help identify neonates at risk of postnatal complications. Neonates born to mothers with diabetes have an increased risk of neonatal morbidity and mortality, and measurement of these new biomarkers may potentially help identify neonates at risk of these complications.

SUBJECTS & METHODS

Copeptin, midregional proadrenomedullin (MR-proADM) and mid-regional pro-A-type natriuretic peptide (MR-proANP) were measured in cord plasma of neonates (n = 63) born to mothers with the three types of diabetes. Associations with maternal glycemic control, mode of delivery and neonatal metabolic acidosis were examined.

RESULTS

Umbilical cord plasma copeptin concentrations were lowest in neonates after elective cesarean sections (6.1 pmol/l; interquartile range [IQR]: 4.5-9.1) compared with emergency cesarean sections (156 pmol/l; IQR: 9.6-311; p = 0.019) and vaginal delivery (831 pmol/l; IQR: 107-2407; p < 0.0001). MR-proADM was also affected by mode of delivery; however, this seemed more likely to be caused by an inverse association with the acid-base balance. In this population, only MR-proANP plasma concentrations were related to type of diabetes. Neonates born to mothers with Type 1 diabetes had higher concentrations (median 260 pmol/l; IQR: 222-318) compared with Type 2 diabetes (175 pmol/l; IQR: 169-200; p = 0.003) and gestational diabetes (200 pmol/l; IQR: 149-276; p = 0.009).

CONCLUSION

Umbilical cord plasma copeptin and MR-proADM concentrations primarily reflect perinatal stress associated with mode of delivery and the degree of fetal acidosis, whereas MR-proANP concentrations are higher in neonates born to mothers with Type 1 diabetes.

Reduction in postnatal cumulative nutritional deficit and improvement of growth in extremely preterm infants

AIM

To evaluate the influence of gestational age (GA) on cumulative nutritional deficit and postnatal growth in extremely preterm (EPT) infants after optimizing nutritional protocol as recently recommended.

METHODS

A prospective, nonrandomized, observational study in extremely preterm (EPT, <28 weeks) and very preterm (VPT, 28-30 weeks) infants.

RESULTS

Eighty-four infants were included (BW: 978 ± 156 g, GA: 27.8 ± 1.3 weeks). Cumulative nutritional deficit increased during first week of life to -290 ± 84 and -285 ± 117 kcal/kg and -4.2 ± 3.1 and -4.8 ± 3.9 g/kg of protein in EPT and VPT groups, respectively. After 6 weeks, only cumulative energy deficit in EPT group remained significant (p < 0.05) even when 96% of theoretical energy intakes were provided. Weight z score decreased during first 3 days in average with initial weight loss, and then, the z score increased during the first 6 weeks of life in the majority (75%) of infants. Cumulative protein deficit during the first week of life was the major determinant of the postnatal growth during the first 6 weeks of life.

CONCLUSION

Cumulative nutritional deficit may be drastically reduced in both EPT and VPT infants after optimizing nutritional policy during the first weeks of life, and the postnatal growth restriction could even be prevented.