Variability of breath hydrogen excretion in breast-fed infants during the first three months of life.

Breath hydrogen excretion was measured serially in breast-fed infants. There was marked variability in H2 excretion, both within and between infants. The findings indicate that unabsorbed food is not the only substrate, and that breath H2 may not be an effective method to assess carbohydrate absorption in young infants.     

Abnormal shoulder girdle muscle tone in premature infants during their first 18 months of life

To document the incidence of and neonatal factors associated with abnormal shoulder girdle muscle tone in premature infants at follow-up, we studied 125 consecutively admitted infants weighing less than 1,750 g treated in The Children's Hospital of Philadelphia intensive care nursery and subsequently seen in the Neonatal Follow-up Program up to 18 months of age. Fifty-seven infants (46%) displayed abnormal shoulder girdle muscle tone which presented clinically as scapular retractions. These infants had significantly lower birth weights (P less than .001) and gestational age (P less than .001) as well as a higher incidence of acute and chronic pulmonary disease (P less than 0.01) and CNS insults (P less than .05) when compared with infants without scapular retractions. The 57 infants with scapular retractions were further divided into two groups: 42 infants (74%) in whom scapular retractions were associated with generalized mild hypertonicity and 15 infants (26%) in whom scapular retractions compensated for trunk and neck hypotonicity. The infants with scapular retractions and hypotonicity had a significantly higher incidence of neonatal neurologic morbidity including seizures, major resuscitations, and birth asphyxia (P less than .01) when compared with the infants with scapular retractions and hypertonicity. Shoulder girdle tone abnormalities in the first year of life inhibit crawling, sitting, and object manipulation and, therefore, may manifest as delays in motor development. Identification of infants with significant neonatal risk factors for tone abnormalities is important to allow for earlier therapeutic intervention.     

Decreased production of specific antibodies to cow's milk proteins in premature infants during the first six months of life

Concentrations of IgG and IgM antibodies to casein, β-lactoglobulin, lactalbumin and bovine serum albumin (BSA) in sera of premature infants of less than 36 weeks gestation, at 5 weeks of age, were less than in age-matched term infants. At 6 months of age IgG antibodies to BSA in preterms were still significantly lower than in term infants.     

Changes of polyamine concentrations in infants during the first six months of life

Polyamines were detected in the blood of infants during the first six months of life. The highest spermidine levels were found at the 2nd and the 4th month after birth. Spermine, on the contrary, does not show significant differences. Different types of diet produced no changes in the polyamine pattern.     

Weight indices during the first 18 months of life in low birthweight infants

A prospective study was carried out among 190 low birthweight neonates (less than 2,500 g) in order to assess their ratio of total body fat by 2 adiposity indices: Weight/Height3 (W/H3) at birth and Weight/Height2 (W/H2) subsequently. Adequate for gestational age (AGA) girls with weight indices (W/H3) above the 10th percentile (AGA/I+) had a lower height than AGA/I- girls on the 6th (p less than 0.01) and 9th (p less than 0.05) months of corrected chronological ages. Mean weight and height of small for gestational age (SGA) neonates with weight indices (W/H3) lower than the 10th percentile (SGA/I-) were similar to the SGA/I+ as soon as 3 months of corrected chronological age. SGA/I+ infants experienced a progressive increase in low weight indices (W/H2) until 15-18 months without significant differences with SGA/I- at 3, 6, 9 months of corrected chronological age. Meanwhile, low indices (W/H2) were more frequently observed in SGA/I- at 15-18 months. Thus the early characteristics in weight indices disclose a lower ratio of body fat in SGA infants than in normal children, at least up to age 15-18 months.     

Respiration during the first six months of life in normal infants: IV. Gender differences

Respiratory rates and breathing pauses of various durations were examined in 19 normal infants, 12 male and 7 female, during the first 6 months of life. Twelve-hour all-night polygraphic recordings were obtained during the first week of life and at 1, 2, 3, 4 and 6 months. A computer program and visual analysis were used to score sleep state and calculate respiratory rates and apnea densities. In the newborn period there were no gender differences. Males breathed faster and exhibited fewer breathing pauses between 2 and 5 sec from one month of age on. The close correlation between respiratory rate and short breathing pauses suggests that the latter are an integral part of normal respiratory regulation. These findings can be explained by gender-related differences in metabolic rate or maturation of the central nervous system.