Human Milk Macronutrients Content: Effect of Advanced Maternal Age

BACKGROUND

Little is known about the effect of advanced maternal age upon macronutrients of human milk. This study was designed to study contents of macronutrients (fat, lactose, and protein) in human milk collected in the first 2 weeks of life in older (≥35 years) compared with younger (<35 years) mothers.

SUBJECTS AND METHODS

Seventy-two lactating mothers (38 older, 34 younger) of newborns were recruited within the first 3 days of delivery. Macronutrient contents were measured at 72 hours, 7 days, and 14 days after delivery using infrared transmission spectroscopy.

RESULTS

The groups did not differ in terms of maternal prepregnancy weight, height, and diet or infant birth weight or gestational age. They differed significantly in terms of maternal age and maternal weight after pregnancy. Fat content in colostrum and carbohydrate content in mature milk were significantly higher in the older mothers group. Moreover, carbohydrates in mature milk correlated positively with maternal age. Fat content at an infant age of 7 days and 2 weeks was not affected by maternal age. There was no significant relationship between maternal body weight for height (or body mass index) and energy, protein, fat or lactose content at any stage.

CONCLUSIONS

Fat content of colostrum and carbohydrate content of mature milk obtained from mothers with advanced age are elevated compared with those of younger mothers. Moreover, there is a positive correlation between maternal age and carbohydrate content in mature milk. The biological significance of our findings is yet to be determined.

Circadian Macronutrients Variations over the First 7 Weeks of Human Milk Feeding of Preterm Infants

BACKGROUND

Little is known about circadian variations of macronutrients content of expressed preterm human milk (HM). This study evaluated diurnal variations of macronutrients and energy content of preterm HM over the first 7 weeks of lactation and tested the hypothesis that values obtained during a morning sample are predictive of those obtained from an evening sample.

MATERIALS AND METHODS

Expressed HM was obtained from 32 mothers of preterm infants (26-33 weeks in gestational age), who routinely expressed all their milk every 3 hours from the beginning of the second to the seventh week after delivery. One aliquot was obtained from the first morning expression and the second from the evening expression. Energy and macronutrients contents were measured using an HM analyzer.

RESULTS

Mean fat and energy contents of all samples obtained during the whole period were significantly higher in evening samples (p < 0.0001). There were no significant differences between morning and evening carbohydrates and protein contents. Concentrations of protein, carbohydrates, and fat from morning samples were predictive of evening concentrations to different extents (R(2) = 0.720, R(2) = 0.663, and R(2) = 0.20, respectively; p < 0.02). The predictability of evening values by morning values was not influenced by the week of lactation at sampling or by individual patients. In repeated-measures analysis of variance performed on 11 patients who completed the whole 7-week period, over time, there was a significant decrease in fat, energy, and protein contents, whereas carbohydrates content remained unchanged. Day-night differences remained significant only for fat content.

CONCLUSIONS

Circadian variations in fat and energy concentrations of HM are consistent over the first 7 weeks of lactation. There are no consistent circadian variations in HM protein and carbohydrates. Over a given day, there are little variations in protein and carbohydrates content, but fat concentrations are more variable, and evening values are less well predicted by morning sample analysis than values for protein or carbohydrates.

Absolute nucleated red blood cells counts do not predict the development of bronchopulmonary dysplasia

OBJECTIVE

We tested the hypothesis that infants with bronchopulmonary dysplasia (BPD) have higher absolute nucleated red blood cells (aNRBCs) counts at birth than controls as a proxy measurement of exposure to intrauterine hypoxia.

METHODS

We studied 39 preterm infants with BPD and compared them to 39 pair-matched controls without BPD. Criteria for exclusion in both groups included factors that may influence the aNRBCs at birth.

RESULTS

In logistic regression, when pre-eclampsia, birthweight, gender, antenatal steroid therapy, 1-min Apgar scores, respiratory distress syndrome (RDS) (or surfactant use), intraventricular hemorrhage of grade 3 or more, nosocomial sepsis, patent ductus arteriosus, and aNRBC counts (or lymphocyte counts) were used as independent variables, and BPD as the dependent variable, only RDS (or its proxy measurement of surfactant use) and nosocomial sepsis remained included in the final analysis.

CONCLUSIONS

aNRBC counts and lymphocyte counts do not appear to be elevated in infants that develop BPD, as compared to pair-matched controls without BPD. We speculate that chronic intrauterine hypoxia does not appear to play a major role in the pathogenesis of BPD. In contrast, postnatal events such as RDS and nosocomial sepsis appear to play a determining role in the pathogenesis of BPD.

Breast milk fat content of mothers to small-for-gestational-age infants

OBJECTIVE

Little is known about the composition of human milk (HM) expressed by mothers of asymmetrically growth-restricted infants. To test the null hypothesis that lactating mothers of small-for-gestational-age (SGA) infants produce milk with fat content similar to that of lactating mothers of infants whose growth is appropriate for gestational age (AGA).

STUDY DESIGN

Fifty-six lactating mothers of newborns (26 SGA and 30 AGA) were recruited within the first 3 days of delivery. Creamatocrit (CMT) levels in HM were measured at 72 h, 7 days and 14 days postdelivery in capillary tubes after centrifugation at 9000 r.p.m. for 5 min.

RESULT

The groups did not differ in terms of maternal age, body mass index, gestational age (GA), pregnancy weight gain and parity. They differed significantly in terms of infant's birth weight by design. The mean CMT levels at the three time points were similar for the two groups. This remained true when timing of the sample (colostrum, transitional, mature milk) was introduced as a confounder in the analysis of variance (general linear model).

CONCLUSION

Fat content of HM is not affected by fetal growth status. We suggest that mothers of SGA infants may be reassured that their milk contains adequate amount of fat that is appropriate for the growth of their infants.

Prolonged duration of breastfeeding does not affect lipid profile in adulthood

BACKGROUND

The Hertfordshire study suggested that age of weaning and methods of infant feeding may influence adult serum low-density lipoprotein cholesterol (LDL-C) and mortality from ischemic heart disease in men. Although breastfeeding <1 year appeared to be protective compared with formula, prolonged breastfeeding (>1 year) was associated with increased LDL-C and mortality. This study tested the effect of breastfeeding duration on lipid profile in young adults.

MATERIALS AND METHODS

Adult volunteers whose mothers could recall the age at which their child was weaned were recruited. We excluded patients with known dyslipidemia, dyslipidemia in a first-degree relative, obesity (body mass index [BMI] >30 kg/m(2)), pregnant or within 3 months of a previous pregnancy, subjects taking medications that may affect lipid profile, or subjects with a chronic medical condition. Nutritional questionnaires and number of weekly hours of exercise were recorded. Lipid profiles were obtained after a night fast.

RESULTS

The three groups (no breastfeeding, breastfeeding 0-6 months, or breastfeeding >9 months) did not differ in terms of age, gender, BMI, level of education, amount of exercise, and dietary style. By stepwise background multiple regression analysis taking into account exercise, nutritional habitus, age, BMI, gender, and socioeconomic status, blood lipids were not affected by duration of breastfeeding.

CONCLUSIONS

Duration of breastfeeding does not affect lipid profiles in young adults. These findings do not support negative messages on the long-term effect of prolonged lactation generated by the Hertfordshire study.

Major losses of fat, carbohydrates and energy content of preterm human milk frozen at -80°C

OBJECTIVE

Long-term storage of human milk (HM) requires freezing at low temperatures, the consequences of which upon macronutrients are unclear. To test the null hypothesis that HM freezing and storage for a range of 1 to 10 weeks at -80 °C does not affect HM fat, protein, lactose and energy contents.

STUDY DESIGN

Samples of HM were obtained from 20 mothers (60 samples) of preterm infants (25 to 35 weeks gestation), who routinely expressed their milk, every 3 h, using an electric pump, from the second to the seventh week after delivery. All samples were frozen at -80 °C for 8 to 83 days (43.8 days average). After thawing and homogenization, energy and macronutrient contents were measured using an HM analyzer.

RESULT

Fat, carbohydrates and energy contents were significantly lower in thawed HM than in fresh HM (fat, fresh vs thawed: 3.72±1.17 vs 3.36±1.19 g/100 ml, P<0.001; carbohydrates, fresh vs thawed: 5.86±0.71 vs 4.09±0.96 g/100 ml, P<0.001; energy, fresh vs thawed: 64.93±12.97 vs 56.63±16.82 kcal/100 ml, P<0.0001), whereas protein content remained unchanged (protein, fresh vs thawed: 1.14±0.36 vs 1.15±0.37 g/100 ml, P=0.7). The decline in carbohydrates content but not in fat and energy correlated significantly with freezing duration.

CONCLUSION

Freezing at -80 °C significantly decreases the energy content of HM, both from fat and carbohydrates. Since quantitatively the decrease in macronutrients was much higher than that published for HM storage at -20 °C, our results do not support freezing HM at -80 °C as the gold standard for long-term storage. We suggest that caloric intake calculations in preterm infants cannot be established based upon fresh HM data.

Secular trends in impact factor of breastfeeding research publications over a 20-year period

OBJECTIVE

The aim of the current study was to determine whether secular changes have occurred in the breastfeeding literature, in terms of number and type of yearly published articles and impact factor of journals publishing these articles.

RESEARCH DESIGN AND SETTING

In order to evaluate all Medline articles related to breastfeeding, we used the Internet URL www.ncbi.nlm.nih.gov/entrez and searched for articles recorded from January 1, 1992 through December 31, 2011 using as a key word "breast milk," "breast feeding," or "human milk." We specifically studied randomized controlled trials (RCTs), clinical trials, case reports, meta-analyses, letters to the editor, reviews, systematic reviews, practice guidelines, and editorials.

RESULTS

There was a linear increase over the years in all articles recorded, from approximately 1,100/year in 1992 to 2,100/year in 2011 (i.e., an approximately 1.9-fold increase [R(2)=0.995, p=0.001]). Concomitant with the yearly increase in the number of published RCTs per year, there was a linear increase in the number of journals publishing articles on breastfeeding per year (from approximately 20 in 1992 to >60 in 2011 [R(2)=0.811, p<0.001]) but an overall decrease in the average impact factor every year (R(2)=0.202, p=0.047). However, the ratio of high-quality articles selected (RCTs+meta-analyses+systematic reviews+CR)/low-quality articles (reviews+editorials+letters to the editor+case reports) increased significantly over time in favor of the former.

CONCLUSIONS

There was a linear increase in the number of publications related to the field of breastfeeding and human milk, and the ratio of high-quality/low-quality articles improved over time, indicating a relative and absolute increase in the number of articles usually considered as being of high quality. There was a significant increase in the number of journals publishing breastfeeding-related articles, with a significant decrease of average impact factor of those journals.

Bach music in preterm infants: no 'Mozart effect' on resting energy expenditure

OBJECTIVE

To study whether Johan Sebastian Bach music has a lowering effect on resting energy expenditure (REE) similar to that of Wolfgang Amadeus Mozart music.

STUDY DESIGN

Prospective, randomized clinical trial with cross-over in 12 healthy, appropriate weights for gestational age (GA), gavage fed, metabolically stable, preterm infants. Infants were randomized to a 30-min period of either Mozart or Bach music or no music over 3 consecutive days. REE was measured every minute by indirect calorimetry.

RESULT

Three REE measurements were performed in each of 12 infants at age 20±15.8 days. Mean GA was 30.17±2.44 weeks and mean birthweight was 1246±239 g. REE was similar during the first 10-min of all three randomization periods. During the next 10-min period, infants exposed to music by Mozart had a trend toward lower REE than when not exposed to music. This trend became significant during the third 10-min period. In contrast, music by Bach or no music did not affect significantly REE during the whole study. On average, the effect size of Mozart music upon REE was a reduction of 7.7% from baseline.

CONCLUSION

Mozart music significantly lowers REE in preterm infants, whereas Bach music has no similar effect. We speculate that 'Mozart effect' must be taken into account when incorporating music in the therapy of preterm infants, as not all types of music may have similar effects upon REE and growth.

Conclusiveness of the Cochrane reviews in nutrition: a systematic analysis

BACKGROUND/OBJECTIVE

To assess the conclusiveness of the Cochrane Reviews (CRs) in the field of Nutrition, we tested the hypotheses that: (1) the majority of CRs is inconclusive; (2) the majority of CRs recognizes the need for further and better studies and (3) the ability to reach a conclusion is dependent on the number of studies performed and number of patients enrolled.

SUBJECTS/METHODS

We selected all 87 CRs in the field of Nutrition available in Cochrane library. Each CR was analyzed for the number of randomized clinical trials (RCTs) found, number of RCTs included for analysis, number of patients enrolled, the stated need for further studies and the reason(s) for it and the conclusiveness of the CR.

RESULTS

Fifty-six out of eighty-seven CRs (64.4%) were conclusive. The average number of available articles, the percentage of articles included, the average number of RCT's retained in the analyses and the total cumulative number of patients enrolled in the studies retained for analysis were significantly higher in conclusive CRs than in non-conclusive ones. The majority of inconclusive CRs (70.9%) recognized the need for further studies, a percentage not significantly different from that found in conclusive ones (58.9%, P=0.26). The percentage of conclusive CRs was not affected by year of publication.

CONCLUSIONS

The majority of CRs in Nutrition is conclusive, but most of them emphasize the need for further studies. The ability for a CR to reach a conclusion is affected by the cumulative patient sample size and number of RCT's included in the analysis.

Vitamin and mineral supplementation of term infants: are they necessary?

This chapter examines the evidence behind the need or not to routinely administer multivitamin and/or mineral preparations to term infants. We reviewed the recommended dietary allowances (RDAs) of vitamins and minerals during the first year of life and examined whether standard nutritional options, i.e. human milk or infant formulae consistent with major international guidelines, satisfy these requirements. We found that RDA cannot adequately be met by either human milk or standard formulas for most vitamins and minerals. We suggest that RDAs are widely overestimated. A particular emphasis is placed on vitamin D and iron, where supplements are needed, and on iodine and vitamin B12, where supplements may be needed depending upon the circumstances.

The effect of advanced maternal age upon human milk fat content

BACKGROUND

Little is known about the effect of maternal age on human milk (HM) composition. This study was designed to study fat content, estimated by creamatocrit (CMT), in HM collected in the first 2 weeks of life in older (≥ 35 years) compared with younger (<35 years) mothers.

STUDY DESIGN AND METHODS

Ninety lactating mothers (48 older, 42 younger) of newborns were recruited within the first 3 days of delivery. CMTs were measured at 72 hours, 7 days, and 14 days after delivery for HM in a capillary tube after centrifugation at 5,366 g for 5 minutes.

RESULTS

The groups did not differ in terms of maternal height and diet, infant birth weight, gestational age (GA), or pregnancy weight gain. They differed significantly in terms of maternal age and parity. Mean colostrum CMT was significantly higher in the group of older mothers. Colostrum CMT correlated positively with maternal age (R(2)=0.11, p=0.006) and inversely with GA (R(2)=0.1, p=0.03) but did not relate with either maternal weight or body mass index. CMT at age 7 days and 2 weeks was not affected by maternal age or GA. In multivariate regression analysis colostrum CMT correlated significantly only with maternal age and GA (R(2)=0.3, p<0.001).

CONCLUSIONS

Colostrum fat content of older mothers is much higher than that of younger mothers and inversely related with GA at delivery. This increase in colostrum fat content obtained from mothers with advanced age may be due to increased fat synthesis and excretion in milk, reduced water content of milk, or a combination of both.

Secular trends in impact factor of neonatology publications over a 10-year period

AIM

  To test the hypotheses that published randomized clinical trials (RCTs) in neonatology with negative results (NR) are more likely to be published in journals with lower impact factor (IF) than those with positive results (PR); that there is an increase in the number of yearly published RCTs; that studies with large sample sizes are likely to be published in journals with higher IF.

METHODS

  We used all English-written RCTs registered in MEDLINE between 1/1/2001-31/12/2010 in the field of neonatology. Each RCT was classified as having a PR or NR. IF of each journal was determined for the year of publication.

RESULTS

  We identified 329 RCTs. Yearly number of RCTs varied between 19 and 46, with no significant consistent linear increase over the years. There was no significant change over the years in average IF or in average patient size. IF and sample size of the studies were not significantly higher in studies with PR than in studies with NR.

CONCLUSION

  The number of RCTs per year in the field of neonatology has stabilized in the past 10 years, and RCTs with positive or negative results are published in journals of similar IF.

Neonatal absolute nucleated red blood cell counts do not predict the development of cystic periventricular leukomalacia

BACKGROUND

Infants with severe intraventricular-periventricular hemorrhage (IVH) have higher absolute nucleated red blood cell counts (aNRBC) at birth (a marker of intrauterine hypoxia) than controls. Periventricular leukomalacia (PVL) is known to be associated with prenatal and postnatal events. Whether PVL is also linked to intrauterine hypoxia is unknown.

OBJECTIVES

To test the hypothesis that infants with PVL have higher aNRBC counts at birth than controls.

METHODS

We studied 14 very low birth weight infants with PVL and compared them with 14 pair-matched controls without PVL. Head ultrasound scans were performed in all infants on days 3-5 and 21-25 of life. Paired tests, Fisher exact tests and stepwise logistic regression were performed for analysis.

RESULTS

The groups were similar for gestational age (GA), birth weight (BW), prolonged rupture of membranes (PROM), Apgar scores, IVH, and aNRBC counts. PVL correlated significantly with low partial pressure of CO2 (PCO2) and IVH (P < 0.01). In logistic regression, when GA, gender, PROM, antenatal steroid therapy, 1 (or 5) minute Apgar scores, IVH grade, nosocomial sepsis, patent ductus arteriosus, necrotizing enterocolitis (NEC), need for pressors, aNRBC counts and lowest PCO2 were used as independent variables, PCO2 (P = 0.002), IVH grade (P= 0.001), GA (P = 0.038), NEC (P = 0.061) and use of dopamine (P = 0.010) remained in the analysis (total R2 = 68.2%).

CONCLUSIONS

In contrast to severe IVH, aNRBC counts do not predict the development of PVL.

Changes in serum parathyroid hormone-related protein in breastfed preterm infants

BACKGROUND

Parathyroid hormone-related protein (PTHrP) has the ability to activate parathyroid hormone receptors and cause hypercalcemia. In a previous study we have demonstrated high concentrations of PTHrP in both term and preterm human milk (HM). PTHrP intestinal absorption and its influence upon calcium homeostasis of the preterm infant have not been studied yet. This study assessed the correlation between PTHrP concentrations in preterm HM and PTHrP in maternal and neonatal serum.

STUDY DESIGN

We collected samples of expressed HM obtained from 16 mothers of preterm infants (25-34 weeks of gestation) and drew blood samples from both mothers and infants on postpartum days 2 and 10. PTHrP concentrations were measured by two-site immunoradiometric assay. Blood calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) concentrations were also measured.

RESULTS

Neither maternal nor neonatal PTHrP serum concentrations varied significantly after 10 days of breastfeeding. There was a correlation between PTHrP concentrations in maternal serum and HM concentrations (R² = 0.24, p = 0.04), but not between HM and neonatal serum concentrations or between PTHrP concentrations in HM and preterm serum concentrations of Ca, P, and ALP.

CONCLUSIONS

Despite high concentrations of PTHrP in preterm HM, serum concentrations of PTHrP of breastfed preterm infants did not increase over time. There was no correlation between PTHrP concentrations in HM and neonatal serum Ca concentration.

Human milk fatty acids profile changes during prolonged lactation: a cross-sectional study

BACKGROUND

Human milk produced during prolonged lactation (> 1 year) is extraordinarily rich in fat and has a higher energy content than human milk produced during short lactation.

OBJECTIVES

To estimate the fatty acid (FA) profile of human milk and to test the hypothesis that the proportion of C12 and C14 (two dietary saturated FA known to most promote hypercholesterolemia) in human milk during prolonged lactation is similar to that in short lactation.

METHODS

We conducted a cross-sectional study of 30 mothers of term infants lactating for more than 1 year as compared with 25 mothers of full-term infants who lactated for 2-6 months. Milk was collected by manual expression in mid-breastfeeding.

RESULTS

The two groups did not differ in maternal height, weight, body mass index, diet, infant birth weight and gestational age, but mothers in the prolonged lactation group were significantly older. There was a significant correlation between lactation duration and C12 or C14. The percentage of all FA combined (except for C12 and C14) decreased significantly overtime. In contrast, C12:0 and C14:0 combined increased significantly during lactation (R2 = 10.0%, P < 0.03).

CONCLUSIONS

Women who lactated for more than 1 year had higher C12 and C14 FA percentages in their milk than women who lactated for 2-6 months.

The effect of olfactory stimulation on energy expenditure in growing preterm infants

AIM

To test the hypothesis that olfactory stimulation in growing healthy preterm infants leads to an increase in resting energy expenditure (REE).

DESIGN

A prospective, randomized clinical trial with crossover was conducted in 20 healthy, appropriate weights for gestational age, gavage-fed preterm infants. Infants were studied while asleep and cared for in a skin servo-controlled convective incubator. Using a pipette, 15 drops of saturated solution of vanillin (Aldrich, Fallavier, France) were dripped to a cloth diaper that was placed on the opposite side of the incubator. REE was measured by indirect calorimetry (DeltaTrac II, Helsinki, Finland) exactly 1 h after feeding. Each infant was studied twice by randomization: after a period of 20 min of vanillin odour or after 20 min without vanillin odour.

RESULTS

We found no statistically significant difference in REE of preterm infants when exposed to vanillin odour (74.5 ± 10.1 kcal/kg/day) in comparison with their REE when not exposed to vanillin odour (79.0 ± 11.3 kcal/kg/day).

CONCLUSIONS

Vanillin odour does not significantly influence REE in metabolically and thermally stable preterm infants.

[Parents compliance to perform the voiding cystourethrogram test after urinary tract infection]

Urinary tract infections (UTIs) occur in 3-5% of girls and 1% of boys. UTIs have been considered an important risk factor for the development of renal insufficiency, hypertension or end-stage renal disease. Hence, there is a need for early diagnosis and management of UTI to prevent renal scarring. The guidelines concerning the prophylactic treatment and the imaging studies have changed during the past year. It was believed that reflux predisposed to renal infection (pyelonephritis) by causing renal injury or scarring and that imaging studies in children with UTI were meant to identify anatomic abnormalities that predispose them to infection and renal scaring. Today, this concept is no longer prevalent and there is no recommendation to perform voiding cystourethrogram (VCUG] after every UTI.

AIM

To examine parents' compliance to perform a VCUG test after hospitalization due to UTI and factors affecting their decision.

METHODS

We performed a retrospective study that included all children who were hospitalized and diagnosed with UTI at "Dana" Children's Medical Center during the period 1/2004 - 12/2005. Hospital file records were collected, and the relevant data were obtained. We collected data regarding the parents' compliance to perform a VCUG according to a telephone interview.

RESULTS

A total of 227 children participated in the study; 179 (78.85%) parents agreed to partake in the interview. Overall, 52% of the children didn't perform the VCUG because of concern about exposure to radiation (55.91%), fear and distress from pain during the test (43.03%), fear of irreversible damage to the urinary tract (40.86%), lack of relevant information (35.48%] and the primary pediatrician's recommendation to postpone the test. The remaining 48% conducted the test because of the hospital doctor's recommendation (94.18%), Primary pediatrician recommendation (94.18%) and because of the desire to terminate prophylactic treatment (63.95%). There is a significant correlation between the doctors' recommendation and the extent and clarity of their explanation to the parents' understanding of the importance of the test, to the parents' satisfaction from the explanation and to the compliance to perform the test.

CONCLUSIONS

There is a need to improve the doctors' explanation regarding the performance of VCUG test post UTI. This will improve the patients' compliance to perform their post discharge recommendation.

Parathyroid hormone-related protein in preterm human milk

BACKGROUND

Parathyroid hormone-related protein (PTHrP) has the ability to activate parathyroid hormone receptors and cause hypercalcemia. High concentrations of PTHrP are found in human breastmilk of mothers of term-infants. It is not known whether PTHrP is excreted in preterm human milk. This study tested the hypothesis that PTHrP concentrations in milk obtained from mothers of preterm infants are similar to those found in milk from mothers of term infants.

METHODS

We collected samples of expressed human milk obtained from 27 mothers of preterm infants (27-34 weeks' gestation) and from 16 mothers of full-term infants. Samples were collected within the first 72 hours postpartum (colostrum) and again at 1 and 2 weeks postpartum. PTHrP concentrations in these samples were measured by two-site immunoradiometric assay.

RESULTS

PTHrP concentrations were significantly higher in samples obtained after 1 week postpartum than in samples obtained during the first 72 hours of life in breastmilk obtained from mothers of both term and preterm infants (P < 0.0001). PTHrP concentrations were similar in colostrum and after 1 week in term and preterm milk. PTHrP concentrations after 2 weeks of lactation were significantly higher in samples obtained from mothers of term infants (P < 0.006).

CONCLUSION

Human milk expressed by mothers of preterm infants contains amounts of PTHrP similar to those measured in milk expressed by mothers of term infants.

Effect of music by Mozart on energy expenditure in growing preterm infants

OBJECTIVE

The rate of weight gain in preterm infants who are exposed to music seems to improve. A potential mechanism could be increased metabolic efficiency; therefore, we conducted this study to test the hypothesis that music by Mozart reduces resting energy expenditure (REE) in growing healthy preterm infants. DESIGN. A prospective, randomized clinical trial with crossover was conducted in 20 healthy, appropriate-weight-for-gestational-age, gavage-fed preterm infants. Infants were randomly assigned to be exposed to a 30-minute period of Mozart music or no music on 2 consecutive days. Metabolic measurements were performed by indirect calorimetry.

RESULTS

REE was similar during the first 10-minute period of both randomization groups. During the next 10-minute period, infants who were exposed to music had a significantly lower REE than when not exposed to music (P = .028). This was also true during the third 10-minute period (P = .03). Thus, on average, the effect size of music on REE is a reduction of approximately 10% to 13% from baseline, an effect obtained within 10 to 30 minutes.

CONCLUSIONS

Exposure to Mozart music significantly lowers REE in healthy preterm infants. We speculate that this effect of music on REE might explain, in part, the improved weight gain that results from this "Mozart effect."

Trends in neonatology and pediatrics publications over the past 12 years

OBJECTIVE

To test the hypothesis that the number of publications in Neonatology and Pediatrics increases over time, and to verify whether the categories of publications all follow the same pattern over time.

DESIGN AND SETTING

We evaluated all Medline articles during 1994-2005. Search was limited to humans, English and to 'newborn' or 'all-child'. We used regression analysis to determine the effect of year-of-publication upon the number-of-publications of each type.

RESULTS

Medline reported 36,141 publications in Neonatology and 169,823 in Pediatrics during the evaluation period. There was a significant linear increase in the number of publications in Neonatology and Pediatrics. There was a steady increase over time in Neonatology and in Pediatrics in meta-analyses, reviews and editorials. There was a steady decrease over time in letters in Neonatology, but no significant change in letters in Pediatrics. While there was no significant change in clinical trials (CTs), randomized control trials (RCTs) in Neonatology, there was a significant increase in CTs and RCTs in Pediatrics.

CONCLUSIONS

The field of neonatology has not had a significant yearly increase of original studies, but has seen an increase of reviews, meta-analyses and editorials. This contrasts with Pediatrics, which shows a similar increase in reviews, meta-analyses and editorials, but also an increase in the number of CTs and RCTs and guidelines.

Consistent circadian variations in creamatocrit over the first 7 weeks of lactation: a longitudinal study

OBJECTIVE

The objective of this study was to test the hypothesis that fat content of expressed human milk from mothers of preterm infants is higher in samples expressed in the evening than in the morning during the first 7 weeks of lactation.

METHODS

The authors collected samples of expressed human milk obtained from 22 mothers of growing preterm infants, born at 26 to 31 weeks gestation, who routinely expressed all their milk every 3 hours using breast pump from the beginning of the second week to the seventh week after delivery. One aliquot was obtained from the first morning expression and the second from the evening expression. The entire aliquot was collected and mixed, and creamatocrit (CMT) was measured in a capillary. Results are expressed as mean +/- standard deviation (SD), and analyses were by repeated measures analysis of variance.

RESULTS

Mean CMT was significantly higher in evening than morning samples during the whole lactation period, week after week (p < 0.0001). Neither CMT values nor the morning-evening difference in CMT values correlated with gestational age, birth weight, or week of lactation. Morning CMT correlated significantly with evening CMT (R(2) = 0.28, p < 0.0001).

CONCLUSIONS

Circadian variations in CMT are consistent during the first 7 weeks of lactation. The authors speculate that if higher caloric content expressed human milk is needed in a specific preterm infant, evening samples should be used preferentially, if available.

Conclusiveness of the Cochrane Neonatal Reviews: a systematic analysis

AIM

To assess the conclusiveness of the Cochrane Neonatal Reviews (CNRs). We tested the hypotheses that: 1) the majority of the reviews is inconclusive; 2) the majority of reviews recognizes the need for further studies; 3) the ability to reach a conclusion is dependent upon both the number of studies and the number of patients. We also aimed to determine whether the conclusiveness of the CNRs was affected by time.

METHODS

We selected CNRs available in the Cochrane Library in June 2004. The number of randomized clinical trials (RCTs) found, number of RCTs included for analysis, number of patients enrolled, the stated need for further studies, and the conclusiveness of CNRs were recorded.

RESULTS

Out of 170 CNRs, 67.7% were conclusive. The average number of articles was similar, but the total number of patients enrolled was three times higher in the conclusive CNRs. The percentage of articles included in conclusive studies was significantly higher than in inconclusive ones. The vast majority of CNRs recognized the need for further studies. The number of studies included correlated significantly with the total number of patients included. The percentage of conclusive CNRs correlated negatively with year of publication.

CONCLUSION

The majority of CNRs is conclusive, but emphasizes the need for further studies. The ability of a CNR to reach a conclusion is affected by the cumulative sample size and by the number of studies performed. The probability of a newer review to be conclusive is lower than that of an older review.

Circadian variations in fat content of expressed breast milk from mothers of preterm infants

BACKGROUND

Little is known about circadian variations of the fat content in expressed human milk by mothers of preterm infants.

OBJECTIVE

To test the hypothesis that the fat content of expressed preterm human milk is higher in samples expressed in the evening (i.e. after 3 daily meals) than in the morning (after a night-long fast).

METHODS

We collected samples of expressed human milk obtained from 39 mothers of hospitalized growing preterm infants aged 7-14 days, with a gestational age at birth ranging from 26 to 33 weeks, who routinely expressed all their milk every 3 hours, during the day time, just before bed time, and as soon as they woke up, using a commercial breast pump (Medela AG, Baar, Switzerland). One sample was obtained from the first morning expression (between 0600 and 0900) and the second from the evening expression (between 2100 and 2400). The entire quantity of expressed milk was collected, mixed and measured in a capillary tube after centrifugation at 9000 rpm for 5 minutes. Creamatocrits (CMT) were performed in duplicates. Each sample was read independently by 2 investigators who were not aware of the origin and time of sampling and the results were averaged. Results are expressed as mean +/- SD, and analyses were by paired t-test and regression analysis.

RESULTS

CMT was significantly higher in evening than in morning samples (7.9 +/- 2.9% vs. 6.6 +/- 2.8%, P = 0.005). Neither CMT nor the morning-evening difference in CMT correlated with gestational age or birthweight. The morning CMT correlated significantly with the evening CMT (P < 0.001).

CONCLUSIONS

There are significant circadian variations in the CMT of expressed preterm human milk. We speculate that if higher caloric content of expressed human milk is needed in a specific preterm infant, evening sample, if available, should be used preferentially.

Nucleated red blood cells in preterm infants with retinopathy of prematurity

OBJECTIVE

The aim of this retrospective study was to examine hematologic indices of potential intrauterine hypoxia, including circulating nucleated red blood cells, lymphocytes, and platelets in preterm infants who developed retinopathy of prematurity (ROP) compared with suitable controls. We hypothesized that higher neonatal absolute nucleated red blood cell (ANRBC) and lymphocyte counts and lower platelets would be found in infants who developed ROP, compared with control infants.

METHODS

Each of 23 infants with ROP was pair matched for gestational age and Apgar scores with a control without ROP. Criteria for exclusion in both groups included factors that may influence the ANRBCs at birth. Venous ANRBC counts were obtained within 1 hour of life. Statistical analyses used paired t tests, a paired Wilcoxon test, and backward stepwise-regression analysis.

RESULTS

Groups did not differ in birth weight, gestational age, Apgar scores, or hematocrit, white blood cell, or platelets counts. The ANRBC counts at birth were significantly higher in infants who developed ROP than in controls.

CONCLUSIONS

Infants who develop ROP have higher ANRBC counts at birth than matched controls. We suggest that increased fetal erythropoiesis exists in preterm infants who later on will develop ROP. If correct, our interpretation supports the theory that long-lasting fetal hypoxia and/or ischemia may play a role in the pathogenesis of ROP.

Fat and energy contents of expressed human breast milk in prolonged lactation

OBJECTIVE

To estimate fat and energy contents of human milk during prolonged lactation.

METHODS

Thirty-four mothers, of term, healthy, growing children, who had been lactating for >1 year (12-39 months) were recruited. Control subjects were 27 mothers, of term infants, who had been lactating for 2 to 6 months. Fat contents of the milk samples were estimated as creamatocrit (CMT) levels. Energy contents of the milk were measured with a bomb calorimeter.

RESULTS

The groups did not differ in terms of maternal height and diet, infant birth weight, gestational age, or breastfeeding frequency. They differed significantly in terms of maternal age, maternal weight, and BMI. The mean CMT levels were 7.36 +/- 2.65% in the short-duration group and 10.65 +/- 5.07% in the long-lactation group. The mean energy contents were 3103.7 +/- 863.2 kJ/L in the short-duration group and 3683.2 +/- 1032.2 kJ/L in the long-duration group. The mean CMT levels and mean energy contents were correlated significantly with the duration of lactation (R2 = 0.22 and R2 = 0.23, respectively). In multivariate regression analysis, CMT levels (or energy contents) were not influenced by maternal age, diet, BMI, or number of daily feedings but remained significantly influenced by the duration of lactation.

CONCLUSIONS

Human milk expressed by mothers who have been lactating for >1 year has significantly increased fat and energy contents, compared with milk expressed by women who have been lactating for shorter periods. During prolonged lactation, the fat energy contribution of breast milk to the infant diet might be significant.

[Special clinical manifestations of Helicobacter pylori infection in children and adolescents]

During the period 1989-1996, we retrospectively investigated 104 children and adolescents with Helicobacter pylori infection diagnosed by gastroscopy. The median age was 12.11 +/- 3.31 years, 55% were female and 45% male. The chief complaint of 92% of the children was abdominal pain, mainly epigastric. The typical macroscopic finding was nodular gastritis. The most common microscopic picture was chronic superficial gastritis with lymphatic follicles and the presence of Helicobacter pylori. We demonstrated correlation between these gastroscopic and histological findings. Children who suffered from peptic ulcer were older than those with nodular gastritis. Most of the Helicobacter pylori positive patients were treated with triple drug therapy. The combination of drugs changed throughout the years according to the newly accepted strategies in the treatment of Helicobacter pylori. The majority of children reported a decrease in symptoms on completion of therapy. Urea breath test was an efficient and convenient method for the follow-up of patients with Helicobacter pylori infection.

Indomethacin-induced early patent ductus arteriosus closure cannot be predicted by a decrease in pulse pressure

Wide pulse pressure is considered to be a sign of patent ductus arteriosus (PDA). We tested the hypothesis that, following indomethacin therapy, PDA closure is associated with a significant decrease in pulse pressure. Thirty-two ventilated preterm infants were echocardiographically diagnosed within the first 24 hours of life with PDA. Systolic, diastolic, and mean arterial blood pressures were measured prior to indomethacin treatment and after echocardiographically confirmed PDA closure. Following PDA closure, systolic and diastolic blood pressures and mean arterial pressure increased significantly without a significant change of pulse pressure (17 +/- 7 to 20 +/- 12 torr). We conclude that in preterm infants with PDA, systolic, diastolic, and mean arterial blood pressures increase significantly within first few days of life. Pulse pressure does not appear to be affected by early PDA closure. We speculate that high pulmonary resistance in the first days of life prevents significant diastolic aortic runoff and leaves pulse pressure unaffected by PDA, as well as by its closure.

Nucleated red blood cells in preterm infants who have necrotizing enterocolitis

Absolute nucleated red blood cell counts for 23 preterm newborn infants who subsequently had development of necrotizing enterocolitis were significantly higher than for 23 control infants. These infants may have been exposed to relative intrauterine hypoxemia, a possible risk factor for the development of necrotizing enterocolitis.

Energy expenditure in human milk- versus formula-fed preterm infants

OBJECTIVE

We compared energy expenditure (EE) of preterm infants fed their mother's milk versus preterm infant formula. Study design A prospective, randomized crossover study of 13 healthy, appropriate weight for gestational age, gavage-fed, preterm infants. Before the study and according to our feeding protocol, infants uniformly received alternate feeds of human milk and formula. Each infant was randomly assigned to 24 hours of formula feeding followed by 24 hours of breast milk or the reverse. Infants were studied asleep, at the end of each 24-hour period. EE was measured by indirect calorimetry 1 hour before feeding, 20 minutes during feeding, and 1 hour after feeding in a servo-controlled convective incubator. Energy content of human milk was analyzed by bomb calorimetry.

RESULTS

EE was significantly lower in breast milk-fed infants during prefeeding (52+/-6 vs 57+/-10 kcal/kg per 24 hours) (P<.05), per feeding (55+/-6 vs 60+/-10 kcal/kg per 24 hours) (P<.05), and at the postfeeding measurement (60+/-7 vs 65+/-7 kcal/kg per 24 hours) (P=.059). After correction of the results for the actual measured energy intake, all statistical differences reached the <.05 level.

CONCLUSIONS

Preterm infants have lower EE when they are fed breast milk than when they are fed preterm infant formula.

Labor does not affect the neonatal absolute nucleated red blood cell count

We investigated whether the presence or absence of physiologic labor may affect the neonatal nucleated red blood cell (RBC) count. We compared absolute nucleated RBC counts taken at approximately 6 hours of life in term infants born by elective cesarean delivery without trial of labor ( n = 32) and in vaginally delivered infants ( n = 28). Venous blood samples were analyzed and differential cell counts were performed manually; absolute nucleated RBC were counted and expressed as an absolute number. There were no significant differences between groups in birth weight, gestational age, maternal age, gravidity, parity, maternal analgesia during labor, 1- and 5-minute Apgar scores, and infant sex. There was a significantly higher hematocrit and RBC count in the vaginally delivered group as compared with the cesarean group. The absolute nucleated RBC, corrected leukocyte and lymphocyte, and platelet counts were strikingly similar in both groups. We conclude that labor does not affect the neonatal nucleated RBC count. This finding supports the speculation that physiologic labor does not induce a fetal hypoxemia severe or prolonged enough to produce hematological evidence of increased erythropoiesis.

Continuous renal replacement therapy for non-renal indications: experience in children

BACKGROUND

The role of continuous renal replacement therapy in patients with acute renal failure is well recognized. CRRT has also become an important modality of treatment in various acute situations without renal failure.

OBJECTIVES

To describe our experience with CRRT in acutely ill infants and children without renal failure.

METHODS

We analyzed all infants and children who underwent CRRT during the years 1998-2000 in the pediatric intensive care unit and we focus our report on those who were treated for non-renal indications.

RESULTS

Fourteen children underwent 16 sessions of CRRT. The indications for CRRT were non-renal in 7 patients (age range 8 days to 16 years, median = 6.5). Three children were comatose from maple syrup urine disease, three were in intractable circulatory failure secondary to septic shock or systemic inflammatory response, and one had sepsis with persistent lactic acidosis and hypernatremia. Three children underwent continuous hemodiafiltration and four had continuous hemofiltration. The mean length of the procedure was 35 +/- 24 hours. All patients responded to treatment within a short period (2-4 hours). No significant complications were observed. Two patients experienced mild hypothermia (34 degrees C), one had transient hypotension and one had an occlusion of the cannula requiring replacement.

CONCLUSION

Our findings suggest that CRRT is a safe and simple procedure with a potential major therapeutic value for treating acute non-renal diseases in the intensive care setting.

A reappraisal of neonatal blood chemistry reference ranges using the Nova M electrodes

The objective of this study is to establish new reference ranges for whole blood electrolytes, gases, and selected chemistries in normal healthy newborn infants obtained from cord blood and at 2-4 hours of life based on modern analytic techniques. Healthy appropriate-for-gestational age (AGA), term infants were studied. Whole venous cord blood and blood drawn at 2-4 hours of life were analyzed for gases, sodium, potassium, chloride, ionized calcium, ionized magnesium, hemoglobin, and hematocrit. Concentrations for blood glucose and blood urea nitrogen were close to older published concentrations. Na(+), K(+), and Cl(-) were significantly different and had much narrower normal margins. New norms are included for blood gases, lactate, iCa, and iMg. We offer a range of values for often-measured blood chemistries in term, healthy infants, using modern laboratory methods. These values could serve as more up-to-date references compared with older values found in major textbooks of Neonatology.

Mode of delivery and neonatal hematocrit

The objective of this paper is to test the hypothesis that the 2-h hematocrit (HCT) is lower in infants born by cesarean section (CS) than in infants born vaginally and that the postnatal rise of HCT is lower in infants born by CS than in infants delivered vaginally. We prospectively studied 31 infants delivered by elective CS, 21 infants delivered by CS because of arrest of descent and 30 vaginally delivered (VD) infants. All pregnancies were term, uncomplicated in nonsmoking mothers. Apgar scores were > 7 at 1 and 5 min. In all infants umbilical cord was clamped early. Umbilical vein and 2-h peripheral venous micro-HCT were measured by centrifugation. Cord-blood HCT, 2-h HCT, and rise in HCT were similar in the two CS groups and significantly lower than in the VD group. In multiple regression, gestational age, Apgar score, or the presence or not of labor did not influence cord-blood HCT, 2-h HCT, or the rise in HCT. Infants born by CS have lower HCT than infants born vaginally. Prediction of 2-h HCT from cord-blood HCT must take into account the mode of delivery.