Catecholamine Response at Birth in Preterm Newborns

Abstract

We compared the extrauterine adaptation of preterm with term newborn infants, by sequentially measuring plasma catecholamine (CAT) levels at birth and during the first 24 h of life. Twenty-seven preterm appropriate-for-gestational-age (AGA) infants, less than 35 weeks gestation, were compared with 26 healthy near-term AGA infants. Modes of delivery and umbilical arterial pH (mean 7.28) did not differ. Infants with asphyxia, presumed sepsis or hypoglycemia were excluded. CAT (norepinephrine, epinephrine, dopamine) levels were measured by radioenzymatic assay in blood samples from maternal vein, cord vein, cord artery and blood samples obtained at 1, 2 and 24 h of postnatal age. At birth, the cord arterial CAT levels were significantly higher than maternal venous CAT levels in both groups of neonates. Plasma epinephrine levels (mean ± SD) at 1 and 2 h of postnatal age were significantly higher in preterm than in near-term newborns (0.98 ± 0.82 nmol/l vs. 0.30 ± 0.21 nmol/l at 1 h; 0.98 ± 0.68 nmol/l vs. 0.28 ± 0.29 nmol/l at 2 h; p < 0.05). The norepinephrine and dopamine measurements did not differ between the two groups studied at birth, 1, 2 and 24 h of postnatal age. These data indicate that the preterm infants (25-35 weeks gestation) are capable of mounting a catecholamine response at birth similar to near-term newborns. The persistent elevation of epinephrine in preterm infants at 1 and 2 h of life may be attributed to either slower clearance of epinephrine or continued stimulation during clinical care in the NICU.

Tissue Doppler imaging in very preterm infants during the first 24 h of life: an observational study

“…Left ventricular output increases twofold to threefold at birth 19 20. This rapid adaption at birth, thought to be triggered by a sudden release of circulating catecholamines,21 22 is also found in preterms 23. However, in 1993, Gill and Weindling24 showed significantly reduced shortening fraction during the first 24 h after birth in a population comparable to ours.…”

Inappropriate secretion of umbilical plasma catecholamines in preterm compared to term neonates

“…LAGERCRANTZ and BISTOLETTI [9], GREENOUGH et al [7], PUOLAKKA et al [22] and MEHANDRU [11] found insignificantly lower arterial catecholamine levels in preterm than in term newborn umbilical vessels. By contrast, NEWNHAM et al [12] suggested equal noradrenaline levels and higher adrenaline levels in preterm compared to 40000 20000.…”

“…Dies traf allerdings nicht auf die Gruppe der Frühgeborenen zu. Im Gegensatz zu anderen Autoren [7,9,11,12,22] waren alle freien Katecholaminspiegel in der Arteria umbilicalis bei früh-gegenüber reifgeborenen Kindern signifikant erniedrigt. Dies ist eher das Resultat einer verminderten Sekretion als einer erhöhten Degradation von Katecholaminen und könnte durch die zunehmende Reifung des sympathisch-adrenergen Systems erklärbar sein [16] sowie durch die große Anzahl von Kaiserschnitten in der Gruppe von Frühgeborenen.…”

Betreuung von Neugeborenen nach Schwangerschaften diabetischer Mütter

“…Das Neugeborene muss nun die Depots zur Energiebereitstellung selbst mobilisieren. Beim gesunden reifen Neugeborenen kommt es zu einem akuten Anstieg der Blutkonzentrationen von Epinephrin, Norepinephrin, Glukagon und Abfall des Insulins [10][11][12] . Diese Hormone stimulieren Glykogen aus der Leber [13] [14,15] .…”