To determine whether significant historical differences distinguish the near-miss for Sudden Infant Death from the infants who died of SIDS, we analysed the histories and clinical data from two groups of infants seen in our University Hospital and from collaborative research group. The data were obtained with the use of a standardised questionnaire and consultation of all available medical data. Sixty-five infants were identified as near-miss for SIDS after they had suffered a severe cardiorespiratory incident during sleep for which no cause could be found despite a complete medical examination. After an autopsy had failed to reveal a cause for the unexpected death 95 cases of SIDS were retained in the study. A series of 353 variables were collected from the parents, the gynaecologists, neonatologists and attending physicians. After statistical analysis, only 15 of the 353 items studied significantly differentiated between the two groups. A step-wise discriminant analysis performed on these items led to the identification of six independent variables: the time of the incident; the circumstances leading to the observation of the child; the child's sleep position; previous minor intestinal problems; the size of the family and the mother's coffee consumption. Most variables indicate that the near-miss infants were discovered and rescued earlier than the infants who died. No other historical information appeared significantly to differentiate between the two groups of infants. These data need confirmation from a prospective epidemiological survey.

Catecholamines (dopamine [DA], norepinephrine [NE], epinephrine [E]), methoxyamines (3-methoxytyramine [MT], normetanephrine [NMN], metanephrine [MN]), DOPA, and acidic metabolites (3,4-dihydroxyphenylacetic acid [DOPAC], vanilmandelic acid [VMA]) were determined in human urines from one day of age to adulthood, in order to investigate sympatho-adrenal development during life. All adrenergic compounds are present in neonate urines on the first day of life, but their postnatal evolution is quite different according to the nature of metabolites. Daily E, MN and VMA amounts remain low until the 10th month of life; daily NE, MT and DOPA levels increase progressively, but, in contrast, NMN amounts are already high in the neonatal period and increase only beyond the fourth year of age. DA is at either age the predominant catecholamine but its elimination is relatively more important in the neonatal period.

Catecholamines (DA, NE, E), methoxyamines (MT, NMN, MN), DOPA and DOPAC were studied in urine of term small for gestational age infants (SGA) and preterm with appropriate birthweights for gestational age (PT) during the first ten days of life. Results were compared to values obtained for full term infants (FT). As a whole no deficit in urine catecholamines was observed in either group of SGA and PT neonates suggesting that capacities to synthesize catecholamines are already developed at birth. Furthermore, in SGA infants, adrenergic function seems to be enhanced during the first four days of life; however, SGA infants with low blood glucose levels excreted amounts of epinephrine similar to those of FT neonates, but much lower than those obtained in normoglycemic SGA neonates. These data suggest that enhanced release of catecholamines is required in SGA infants to maintain the glycemic homeostasis. In premature infants, the adrenergic pattern was highly altered only in younger preterm neonates (31 weeks of gestational age) who excreted more catecholamines than older preterm babies (33 to 36 weeks) or full term neonates; this catecholamine increase in urine of young preterm infants might be related to immaturity of storage vesicles and/or to thermoregulatory or respiratory events. On the other hand, a striking deficit in excretion of DOPAC was observed in small for gestational age infants and in young preterm neonates during the first ten days of life. DOPAC excretion was even lower in SGA than in young preterm neonates. These findings suggest that the maturation of dopaminergic neurons occurs late in gestational age and is greatly dependent on nutritional factors.

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