Calcitonin and parathyroid hormone in newborn infants with fracture of the clavicle.

Determinations of serum calcium (Ca), phosphorus (P), calcitonin (CT), and parathyroid hormone (PTH) were carried out in 36 full-term newborn infants with fracture of the clavicle (CF) and in 46 normal neonates (N). At the 6th hour of life the CF neonates demonstrated lower serum Ca and higher serum CT in comparison with normal infants. In the hours following, no significant differences between the two groups for the Ca levels were found, whereas serum CT remained significantly higher in the CF newborns at the 24th, 48th, and 72nd hour of life. Significant differences between normal and CF infants in the PTH serum levels were detected only at the 48th hour, when PTH was lower in the CF newborns. The results of this investigation indicate that the fracture of the clavicle is a significant and peculiar factor in stimulating CT secretion. Serum Ca level appeared to be controlled by CT rather than auto-regulating the secretion of the hormone.

[Serum concentrations of calcitonin and parathormone in the cord blood of premature infants]. / Concentrazioni seriche di calcitonina e paratormone nel sangue funicolare del prematuro.

Determinations of serum calcium (Ca), calcitonin (CT) and parathyroid hormone (PTH) were carried out in mixed cord blood of 23 preterm infants. Gestational age ranged between 25 and 37 weeks. 17 of theme were vaginally delivered while 6 were delivered by emergency Caesarean section. 4 neonates died because of respiratory distress syndrome. The serum was stored at -30 degrees C until the determinations. Serum Ca levels were determined by spectrophotometry while CT and PTH levels by RIA (Immuno Nuclear Co). In cord serum the mean (M +/- SE) Ca,CT and PTH concentrations of all neonates examined were respectively: 9,9 +/- 0,6 mg/dl; 176 +/- 44 pg/ml and 1100 +/- 446 pg/ml. Serum values of CT and PTH in preterm newborns delivered by emergency Caesarean section were significantly higher than in those neonates vaginally delivered (CT: 302 +/- 115 vs 94 +/- 9 pg/ml; p less than 0.005) (PTH:2655 +/- 1857 vs 466 +/- 59 pg/ml; p less than 0.05). No differences were observed between serum CT and PTH levels in preterm neonates of different gestational age. Both CT and PTH serum concentrations were higher in neonates who died. In conclusion, the preterm neonate is able to secrete both peptides and to maintain Ca homeostasis; the mode of delivery likely affects the CT and PTH secretion; unexplainable high CT and PTH serum levels were detected in poor outcome preterm infants.

Relationship between mode of delivery and neonatal calcium homeostasis.

Serum levels of calcium (Ca), calcitonin (CT) and parathyroid hormone (PTH) were determined in cord blood of 229 newborns. In 136 newborns the tests were repeated 24 h later. The probands were divided into four groups according to mode of delivery: (1) spontaneous; (2) elective caesarean section without labour; (3) elective caesarean section in labour; (4) emergency caesarean section with fetal distress. Newborns in group 2 had significantly lower Ca and CT levels and significantly higher PTH concentrations in cord blood than the other three groups. In all groups Ca and PTH concentrations were negatively correlated. At 24 h, mean Ca levels had decreased and mean CT and PTH concentrations had increased in all four groups. Newborns in group 2 still had lower Ca levels but higher CT and PTH concentrations. At that time there were negative correlations between Ca and CT levels in groups 1 and 2 and between Ca and PTH concentrations in group 1. These data demonstrate that without labour, cord blood Ca and CT levels are lower and PTH concentrations are higher. The low 24 h calcium in newborns delivered without labour is explained by the lower Ca levels at birth and a tremendous increase of CT. The PTH secretion in full-term newborns is very substantial and negatively correlated with Ca levels.

[The effects of diet on the secretion of calcitonin in the newborn infant]. / Effetti della dieta sulla secrezione di calcitonina nel neonato.

Determinations of serum calcium (Ca), phosphorus (P) and calcitonin (CT) were carried out in two groups of full term newborn infants: 80 on bottle feeding (group A) and 80 breast feeding (group B). Samples of blood were drawn at 1, 6, 12, 24, 48, 72, 96 and 168 hours of life. Each newborn was tested no more than twice. No differences between the two groups could be detected before the 72th hour. At that time, the Ca of group A was significantly lower than Ca of group B while the CT and P were significantly higher in the same group A. So that, the P serum level appears to be one of the most important factor regulating the homeostasis of Ca after the first 72 hours of life.

[The secretion of calcitonin in the newborn infant in relation to the method of delivery]. / La secrezione di calcitonina nel neonato in relazione alle modalita' del parto.

Determinations of serum (Ca) and calcitonin (CT) were carried out in 80 full term newborn infants. 40 of them were born by elective Caesarean section (ECS) while 40 were born by normal vaginal delivery (VD). Samples of blood were drawn at 1, 24, 48, 168 hours of life. Each newborn was tested no more than twice. Serum Ca of ECS at 24th hour was significantly less than Ca of VD. At the same time CT of ECS was significantly higher than CT of VD. A negative significant correlation between Ca and CT was observed. The data demonstrate the key role of CT in the homeostasis of Ca in the first hours of life. In addition, the results were suggestive for a dependence of CT secretion on the stress of birth.

[Serum levels of parathormone, calcium, magnesium and phosphorus in the perinatal period]. / Livelli serici di paratormone, calcio, magnesio e fosforo nel periodo perinatale.

Two groups of newborns on different diets were studied: group A was given artificial milk, while group B was breast fed. Blood samples from the cord artery and vein were taken at birth and further blood samples after 1, 6, 12, 24, 48, 72, 96 and 168 hours. No baby underwent more than three blood samples. Calcium (Ca), magnesium (Mg), phosphorus (P) and parathormone (PTH) were measured in all samples. There was a rapid increase in PTH levels in all subjects in the first hours after birth. At 48th the babies in group A had significantly higher serum levels of P than the group B subjects, and their serum Ca and Mg levels were significantly lower. At 72th PTH serum levels were significantly higher in group A, while Ca and Mg levels were significantly higher in group B. In conclusion, the subjects demonstrated a normal secretion of PTH at birth, and the type of diet notably influenced the homeostasis of calcium in the perinatal period.

Calcium homeostasis in the first days of life in relation to feeding.

Determinations of serum calcium (Ca), phosphorus (P), magnesium (Mg), calcitonin (CT) and parathyroid hormone (PTH) were carried out in full term newborn infants during the first 168 h of life. The infants were randomly assigned to two different diets: glucose and breast feeding (BF) only or early formula feeding (F). The Ca serum levels decreased from birth to the 24th h; after that time they increased until the 72nd h. The values of serum Ca at the 48th and 72nd h were significantly lower in the F than in the BF group. In contrast, the P serum levels increased from birth to the 48th h and then they decreased; the values of serum P at the 48th h were significantly higher in F than in the BF group. The CT serum levels increased from birth to the 24th h and then they decreased. No difference between the F and BF groups was found during the first 48 h, while at the 72nd h the F group demonstrated significantly higher values of serum CT. PTH serum levels also increased from birth to the 24th h with significantly higher values at the 72nd h in the F group. The results of this investigation demonstrate that the difference in feeding in the first hours of life affects the calcium homeostasis and the secretion of hormones involved in the regulation of serum Ca levels.

Epidemiologic study of neonatal jaundice. A survey of contributing factors.

In the attempt to detect factors influencing bilirubinemia in healthy full-term or near-term newborn infants, a statistical analysis was carried out on a population of 1,126 neonates to study the variables possibly associated with maximum bilirubin values reached in the first days of life. The following variables were studied: maximum bilirubin level (maxBIL), sex, mode of delivery, gestational age, birthweight, ratio of birthweight/weight on 5th day, Apgar score, Rh and ABO incompatibility. Blood glucose and calcium levels, haematocrit, intake of breast milk, formula and glucose solution were also evaluated during the first 5 days of life. Higher maxBIL was found in males compared to females, after spontaneous delivery vs. emergency caesarean section, after caesarean section without fetal distress vs. emergency caesarean section, and in ABO incompatibility vs. no ABO incompatibility. Statistically significant inverse correlations were observed between maxBIL and gestational age, birth weight, blood glucose, and SE-calcium. Significant positive correlations were found between maxBIL and haematocrit and breast milk intake. A multiple regression analysis between maxBIL and the significantly correlated parameters showed that only gestational age and birth weight remained significantly correlated with maxBIL. The results of the present investigation confirm that the factors most commonly reported as being responsible for neonatal hyperbilirubinemia do in fact play a role, although it can be considered almost negligible with the exception of gender, mode of delivery, ABO incompatibility, birthweight and gestational age.