Gary M Chan

The effect of 1,25(OH)2 vitamin D3 supplementation in premature infants

The effects of 1,25(OH) 2 D 3 in the prophylaxis of neonatal hypocalcemia were studied in 32 premature infants. Four groups of eight infants were matched individually for gestation and evidence of birth asphyxia, and given daily 1 μg of 1,25(OH) 2 D 3 , 0.05 μg/kg/day 1,25(OH) 2 D 3 , 400 IU vitamin D 2 , or placebo orally from 12 to 72 hours of age. Prestudy ionized calcium values were 2 D 3 , 1 μg/day, had significantly higher iCa values, 3.6±0.10 mg/dl (mean±SEM) vs 3.2±0.10 mg/dl at 12 hours (paired t, P 2 D 3 had serum PTH values lower than pretreatment, 59±9 vs 137±58 μl-Eq/ml (Wilcoxon Rank, P P 2 D 3 , the average increase being 1.2 vs 2 D 3 may be useful for the prophylaxis of hypocalcemia.

Neonatal hypocalcemia mechanism of occurrence and management.

Early neonatal hypocalcemia occurs in premature infants, infants with birth asphyxia, and infants of diabetic mothers. Etiological considerations include decreased calcium (Ca) supply, increased endogenous phosphate load, hypomagnesemia, alkali therapy, functional hypoparathyroidism, defects in vitamin D metabolism, and possibly calcitonin excess. Late neonatal hypocalcemia occurs, with malabsorption of magnesium (Mg), increased exogenous phosphate loading, after alkali therapy of diarrheal acidosis, hypoparathyroidism, and vitamin D related disorders. The therapy of hypocalcemia includes oral or iv Ca salts and in the near future, possibly the newly discovered vitamin D metabolites.

1,25-dihydroxyvitamin D3 in childhood hepatic osteodystrophy

Osteodystrophy frequently accompanies severe childhood hepatobiliary disease. Proposed causes include malabsorption of vitamin D and calcium, and diminished 25-hydroxylation of vitamin D. Two children, ages 23 and 35 months, with radiographic and biochemical evidence of rickets with extrahepatic biliary atresia, were treated with 1,25-dihydroxyvitamin D3. The minimal effective therapeutic dose and efficacy of 1,25-(OH)2D3 in the treatment of rickets associated with severe childhood hepatic disease were determined. Oral 1,25-(OH)2D3 was ineffective at doses of 0.10 microgram/kg/day. Parenteral doses of 0.20 microgram/kg/day effectively produced radiographic, bone mineral (photon absorptiometric), and biochemical evidence of healing. The need for four times the physiologic dose of 1,25-(OH)2D3 by the parenteral route suggested enhanced catabolism of, or end-organ resistance to, 1,25-(OH)2D3 in our patients with severe cholestatic liver disease treated with phenobarbital.

NEUROLOGIC DEVELOPMENT OF PREMATURES TREATED FOR NEONATAL HYPOCALCEMIA(HC)

During the first 72 hrs of life, 30% of premature (≤37wks) develop HC. Possible sequelae of early HC have not been examined. Twelve well AGA prematures were studied in matched pairs (gestation and Apgar) and given prophylactic doses of 1, 25 dihydroxyvit 03 (l,25(OH)2D3 - the active D metabolite), or vit D2 400 IU(controls) during the first 3 days. Infants were studied prospectively for degree of tremors on day 1, 2, 3; Brazelton Behavior Assessment (BBA) at 40wks postconception; and Gesell Developmental Exam at 3 & 6 mos. Exams were blinded to ionized Ca (ICa, Orion SS-20) and treatment group. All prestudy iCa were <3.5mg%. By 48hrs, the 1,25(OH)2D3 group had significantly higher iCa, 3.6±0.1mg% (mean±SEM) vs 3.2±0.1 at 12 hrs (paired t, p<.05); controls did not change. Degree of tremors was not related to iCa. Controls were less responsive to BBA orientation (visual, auditory and combined) items than 1, 25(OH)2D3 group, 4.1±.16vs 5.0±.21(t test, p<.01). The 3 mo Gesell was lower for controls vs 1, 25(OH)2D3, 89±3 vs 99±4 (p<.06) and was 110±1 vs 116±1 at 6 mo (p<.01). Eight of the 12 infants were rematched blindly in pairs for Apgar, gestation and HC at 48 hrs vs normocalcemia (NC). HC infants appeared less responsive than NC in the BBA visual-auditory item, 5±0.6 vs 6±.4 (Wilcoxon-Mann, p<.07), to need more consoling (6.6±0.3 vs 7.6±.4, p<.10) and to be more excitable (5.6±.3 vs 6.3±.4, p<.10). No differences were found between HC and NC in 386 mo Gesell. Early neonatal hypocalcemia appears to have an effect on the newborns ability to respond to social(orientation) stimuli; long term sequelae are uncertain.

Growth Rates in Very Low Birth Weight Infants Fed Preterm Formula or Fortified Human Milk 1501

Growth Rates in Very Low Birth Weight Infants Fed Preterm Formula or Fortified Human Milk 1501

MATERNAL ACQUAINTANCE WITH ADOPTED AND BIRTH INFANTS

The purpose of this study was a) to investigate the effects of teaching mothers unique behavioral cues of their adopted infant and b) to learn if there is a difference between mothering of adopted and birth infants. A pretest, post-test experimental prospective design was used with random assignment of mother-adopted infant dyads. Dyads were randomized into experimental and non-experimental groups. Infants were tested using Massies “Mother infant Attachment Indicators During Stress”. A teaching session of specific behavioral cues was given to only the experimental group. Post-test scoring was evaluated by a blind observer; interrater reliability agreement was 0.90. Mean age of the 17 adoptive mothers was 33±4 years; of the adopted infants was 11±9 weeks. Age matched birth mothers formed the control group. The mean age of the 13 birth mothers was 31±5 years; of the birth infants was 8±9 weeks. Differences demonstrated between birth and adopted dyads were: affect (p<.07), holding (p<.03), infant gazing (p<.05) and maternal gazing (p<.002). Differences between adoptive and birth mothering were reflected in holding (p<.08), touching (p<.05), and vocalizing (p<.03). All mothers were interviewed and the qualitative analyses demonstrated seven themes. We have found a difference in the maternal-adopted infant dyad when compared to birth mother-infant dyads. Mothering of adopted infants may also be changed temporarily by a specific teaching intervention.

ADOPTIVE MATERNAL CONCERNS AND BELIEFS

As Part of a larger study of maternal-adopted infant behaviors, an interview schedule was administered to 17 adoptive and 13 birth mothers. A qualitative item analysis was used for the interviews. Comparisons were made between birth and adoptive mothers responses. Mean age of the adoptive mothers was 33.6±4 yrs with adopted infants 11±9 weeks. Mean age of the birth mothers was 31.3±5 yrs with infants 8±9 weeks. There was no difference in SES, maternal education or previous mothering experience. Four themes developed: 1) fantasy about their infant; 2) maternal role acquisition; 3) anticipatory planning; and 4) infants characteristics. Ninety-two percent of birth mothers had fantasy about their infant. However, 24% of adoptive mothers fantasized that their infant would be taken away. While 92% of birth mothers described their maternal role acquisition as gradual, 52% of adoptive mothers stated it was “right away”. 29% felt the adopted infant was a stranger and they felt like a “babysitter”. Anticipatory planning or “nesting” behaviors were described by 77% of birth mothers; only 29% of adoptive mothers performed nesting behaviors prior to placement; 41% after placement. Both birth and adoptive mothers had similar beliefs regarding infants activity level, physical features, temperament and cognitive features. Themes that emerged that were of concern to adoptive mothers were: the shared experience of adoption (due to birth parents), ambiguity or protective coping feeling of possible relinquishment and antagonistic feelings regarding the adoption process. Thus, our study found differences in concerns and feelings between birth and adoptive mothers.

EFFECT OF PHOTOTHERAPY ON 25-HYDROXYVITAMIN D |[lpar]|25-OHD|[rpar]|

Ultraviolet (UV) irradiation of akin activates the conversion of provitamin D to vitamin D3 which is subsequently hydroxylated to 25-OHD. Phototherapy might increase the UV irradiation received by infants, with possible effects on neonatal vit D status. Eight fullterm, appropriate for gestation infants receiving phototherapy for physiologic jaundice were pair-matched for race and postnatal age with 8 controls. All infants had 5-minute Apgar score > 6 and were on the same milk formula. Blood samples were obtained prior to, at the midpoint and after 48 hours of phototherapy (or corresponding ages in controls). Irradiance was measured inside the isolette with a Research radiometer at 30 cms from the radiant source (8 GE, 20 watt daylight fluorescent lamps). Irradiance in the UV wavelength was low and ranged from 0.1 to 1.7 × 10−7 watts/cm2/nm compared with the blue wave length irradiance of 6 to 18 × 10−7 watts/cm2/nm. In phototherapy treated infants, serum 25-OHD, (Belseys method, normal 13 to 81 ng/ml) was 56±3 (mean±SE), 53±3 and 51±4 for pre-, during and post-therapy samples respectively (paired t, not significant); serum Ca was 10.1±0.2, 10.3±0.4 and 10.0±0.2 mg/dl (NS); serum bilirubin was 11.5±0.7, 10.8±0.5, 8.6±0.6 (p < 0.001). In control infants, serum 25-OHD, Ca and bilirubin did not change over the period studied. Average dally vit D intake for phototherapy and controls was 141±6 vs 180±20 I.U. (NS). Thus, ultraviolet irradiation from conventional phototherapy is minimal and does not significantly affect serum 25-hydroxyvitamin D levels in infants.