[Neonatal tongue-tie: myths and science]

Anatomical restraining of tongue movement (tongue-tie, ankyloglossia) has been known for centuries and the subject of dozens of articles. The heated debate persists on its clinical significance and indications for treatment. Most authorities in the field of infant feeding and Lactation agree that breastfeeding problems, such as nipple pain and latching difficulties, are common signs of clinicaLly significant tongue-tie and indications for performing a frenotomy, while the sole presence of a visible lingual frenulum is not. In contrast, the lack of a visible frenulum does not rule out the diagnosis of clinically significant tongue-tie since submucosal ties, also called "posterior tongue-tie", may interfere with efficient breastfeeding. Whether tongue-tie interferes with speech articulation to a significant extent is currently unknown. Theoretically, articulation of some consonants (e.g., /s/, /th/, /r/) would be affected by impeded tongue movement. These articulation problems are, however, Less common than tongue-tie itself, and children and adults characteristically use various compensatory techniques of mouth opening and tongue movements. When it is indicated, frenotomy is performed by lifting the tongue and snipping the frenulum with scissors. Complications of frenotomy are rare and consist mainly of self-limited minor bleeding. The significance of posterior tongue tie and the long-term effects of frenotomy performed during early infancy are unresolved issues.

Neonatal blood glucose concentrations in caesarean and vaginally delivered term infants

BACKGROUND

Little is known about the glucose concentrations at and after birth of infants delivered by caesarean section (CS), when compared with infants born vaginally (VD).

AIM

To compare venous cord blood glucose concentrations of term infants born after elective CS to infants born by VD. We studied the null hypothesis that mode of delivery does not affect neonatal blood glucose values.

METHODS

We compared cord blood glucose concentrations in healthy term infants born after VD (n = 16) or by elective CS (n = 21). Glucose concentrations were obtained immediately at birth from the umbilical cord. Kruskal-Wallis was used to compare glucose concentrations and demographic variables between the groups.

RESULTS

Gestational age was 39.6 ± 0.8 weeks in VD group vs. 38.7 ± 0.9 weeks in CS group, and birthweight was 3359 ± 494 vs. 3500 ± 528 g. Cord blood glucose concentration was higher in VD (81.3 ± 16.9 mg/dL) than CS infants (70.3 ± 9.7 mg/dL, p = 0.039). The change in blood glucose concentration over the first 2-h of life differed significantly between the two groups, being an increase in CS versus a decrease in VD infants (-3.5 ± 15.2 vs. -15.4 ± 24.6 mg/dL, p = 0.013).

CONCLUSIONS

Glucose concentrations in VD infants are higher than in infants born by elective CS without labour.

Effect of magnesium sulfate concentration on serum ionized magnesium in vitro

We undertook this in vitro study to quantify the effect that addition of magnesium (Mg) sulfate to neonatal serum, as compared with adult serum, might have on ionized Mg (Mg (2+)) concentration. We used one cord blood sample and one adult blood sample that we made hypermagnesemic by adding various amounts of magnesium sulfate to study five levels of serum Mg. Each sample was then studied at one of three levels of pH, from extreme alkalosis to extreme acidosis. We measured the changes in serum Mg (2+) and serum ionized calcium (Ca (2+)) in reaction to these changes in pH and Mg. At each pH level, there was an exponential increase in the serum Mg (2+) (and no significant change in serum Ca (2+)) with increasing serum Mg. Multiple regression analysis using Mg (2+) as the dependent variable and baseline Ca (2+), phosphorous, albumin, and blood type (adult versus cord blood) as well as blood pH and serum Mg as independent variables indicated that serum Mg and pH were the only variables significantly influencing serum Mg (2+). Within the range of serum Mg considered, the addition of magnesium sulfate in vitro causes an exponential increase in Mg (2+) and no significant change in serum Ca (2+).

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."

Energy expenditure for breastfeeding and bottle-feeding preterm infants

OBJECTIVE

We hypothesized that resting energy expenditure (REE) would be higher after breastfeeding than after bottle-feeding.

METHODS

Nineteen preterm infants (gestational age: 32 weeks) in stable condition who were nourished entirely with their mothers' breast milk were assigned randomly to feeding either by bottle or at the breast. Each infant served as his or her own control subject. REE was measured for 20 minutes after feeding. Breast milk quantity was evaluated with prefeeding and postfeeding weighing. REE values for bottle-feeding and breastfeeding were compared with paired t tests.

RESULTS

Contrary to our null hypothesis, the group's mean REE values after bottle-feeding and breastfeeding were very similar (284.7 +/- 26.8 kJ/kg per day [68.3 +/- 6.4 kcal/kg per day] vs 282.6 +/- 28.5 kJ/kg per day [67.5 +/- 6.8 kcal/kg per day]; not significant). The duration of feeding was significantly longer for breastfeeding than for bottle-feeding (20.1 +/- 7.9 vs 7.8 +/- 2.9 minutes; P < .0001).

CONCLUSION

There was no significant difference in REE when infants were breastfed versus bottle-fed. Longer feeding times at the breast did not increase REE. We speculate that it is safe to recommend feeding at the breast for infants born at >32 weeks when they can tolerate oral feeding.

Sleep and physical growth in infants during the first 6 months

The aim of this study was to explore the relationships between infant sleep patterns and infant physical growth (weight for length ratio) using both objective and subjective sleep measures. Ninety-six first-born, healthy 6-month-old infants and their parents participated in the study. Infant sleep was assessed by actigraphy for four consecutive nights and by the Brief Infant Sleep Questionnaire (BISQ). In addition, parents were asked to complete background and developmental questionnaires. Questions about feeding methods were included in the developmental questionnaire. Infants' weight and length were assessed during a standard checkup at the infant-care clinic when the infants were 6 months old. Significant correlations were found between infant sleep and growth after controlling for potential infant and family confounding factors. Actigraphic sleep percentage and reported sleep duration were correlated negatively with the weight-to-length ratio measures. Sex-related differences in the associations between sleep and physical growth were found. Breast feeding at night was correlated with a more fragmented sleep, but not with physical growth. These findings suggest that sleep is related significantly to physical growth as early as in the first months of life. The study supports increasing evidence from recent studies demonstrating a link between short sleep duration and weight gain and obesity in young children.

Neonatal respiratory morbidity after elective cesarean section

OBJECTIVE

The objective of this study was to examine the rate of respiratory morbidity in neonates delivered by elective cesarean delivery (ECD) at term, with a definite confirmation of gestational age (GA) by 1st-trimester ultrasound.

METHODS

Consecutive women carrying a singleton pregnancy and undergoing ECD at term (>38 1/7 weeks), confirmed by 1st-trimester ultrasound, were included in the study group. Multiple gestations, cesarean section (CS) in labor, CS performed after rupture of membranes and induced deliveries were excluded. The control group included women with a singleton pregnancy at term (>38 1/7 weeks) who delivered spontaneously. This group of women was randomly selected during the study period.

RESULTS

The study group included 277 women delivered by ECD. The control group consisted of 311 women. Five newborns in the study group and none in the control group were admitted to the neonatal intensive care unit (NICU) due to respiratory disorders (p < 0.02). Excluding diabetic women did not change the results. On multivariate analysis, no other factors were found to independently influence the risk of respiratory complications.

CONCLUSION

In our study, the rate of respiratory morbidity was found to be significantly higher in neonates delivered by ECD compared to those delivered vaginally. The fact that GA was confirmed by 1st-trimester ultrasound makes iatrogenic prematurity an unlikely sole cause for this excess morbidity.

Effect of birth weight and postnatal age upon resting energy expenditure in preterm infants

Our objective was to establish the role of gestational age, birth weight, and postnatal age upon resting energy expenditure (REE) in incubated preterm infants. We hypothesized that at the time these infants are close to being weaned from their incubator, their REE is inversely related to gestational age or birth weight and directly related to postnatal age and weight gain. Infants born at a birth weight of 500 to 2000 g were eligible for the study when they reached a weight of 1500 to 2100 g. All infants were clinically and thermally stable while cared for in a skin servo controlled incubator. REE (kcal/kg body weight/d) was measured 2 hours after feeding while the infants were quietly asleep, using a Datex oxygen consumption analyzer (DELTATRAC II (TM); Datex-Ohmeda Instrumentarium, Helsinki, Finland), based on the principles of indirect calorimetry. There were 42 infants recruited in the study. In univariate analysis, no significant correlation was found between gestational age and REE, but REE was significantly and inversely correlated with birth weight ( R(2) = 0.243, P < 0.001). There was also a significant correlation between REE and postnatal age ( R(2) = 0.203, P = 0.003) and with weight gain ( R(2) = 0.176, P = 0.006). In backward stepwise regression analysis, the effect of birth weight or postnatal age or daily weight gain (g) upon REE remained significant even after taking into account sex, energy intake, and type of feeding. Birth weight, postnatal age, and daily weight gain significantly affect REE, even after taking into account energy intake, sex, and type of feeding. Weight may be a more important parameter in the control of thermoregulation of the preterm infant than gestational age.

When should phototherapy be stopped? A pilot study comparing two targets of serum bilirubin concentration

OBJECTIVE

The objective of this study was to compare the outcome of two groups of jaundiced newborns randomized to one of the two targets of total serum bilirubin (TSB) for phototherapy discontinuation.

DESIGN

Infants treated with phototherapy were assigned to two groups: in the 'high-threshold' group, phototherapy was interrupted when TSB decreased to >/=1 mg/dL (17 micromol/L) below the limit requiring phototherapy and in the 'low-threshold' group when TSB decreased to >/=3 mg/dL (51 micromol/L) below the same limit.

RESULTS

Fifty-two infants were enrolled, 25 in the high- and 27 in the low-threshold group. Phototherapy duration was significantly shorter in the high- than in the low-threshold group (22.3 +/- 13 vs. 27.6 +/- 12 h, respectively, p = 0.03). Length of hospital stay was 84+/-30 h in the high- and 94 +/- 24 h in the low-threshold group (p = 0.05). Additional phototherapy was required in 20% of the high- versus 18% of the low-threshold group (p = 0.58). In the presence of haemolysis or G6PD deficiency, 28% of the infants required re-phototherapy and 8.3% when such factors were absent (p = 0.06).

CONCLUSION

Phototherapy duration may be shortened by using higher TSB limits for interruption. When hyperbilirubinaemia is accompanied by risk factors, the infants should be followed for longer periods, since some of them will need re-phototherapy.

Reducing blood transfusion requirements in preterm infants by a new device: a pilot study

OBJECTIVE

To test a new device designed to salvage red blood cells (RBCs) from blood samples drawn from preterm infants, with the intent of decreasing blood loss and lowering the requirements for RBC transfusions.

DESIGN

A case-controlled pilot study was conducted in two Israeli neonatal intensive care units in large municipal hospitals. Twenty low-birthweight preterm infants were randomly and equally divided into the ErythroSave group or a control group. All blood tests in the study group (except for complete blood count and coagulation parameters) were obtained during the first week of life by the new device in the study group and by ordinary syringes in the control group. The main outcome measure was the total number of units of blood needed.

RESULTS

The average volume of blood obtained for laboratory analyses from each infant was 27 mL in the ErythroSave group and 24 mL in controls (not significant). The average volume of transfused packed cells was 6.4 mL for the ErythroSave group and 21.3 mL for the controls (p = 0.008).

CONCLUSION

The use of ErythroSave for sampling blood significantly reduced blood transfusion requirements in premature infants compared to sampling by conventional syringes.

Energy expenditure in growing preterm infants receiving massage therapy

OBJECTIVE

Massage therapy has been consistently shown to increase weight gain in preterm infants. The mechanism of this presumed improved metabolic efficiency is unknown. We conducted the following trial to test the hypothesis that massage therapy reduces energy expenditure in growing healthy preterm infants.

STUDY DESIGN

A prospective, randomized, cross-over design study was conducted in 10 healthy, appropriate weights for gestational age, gavage fed preterm infants. Each infant was studied twice: after a period of either 5 days of massage therapy, or after a period of 5 days without massage therapy. Infants were randomized to 5 days of massage followed by 5 days of no massage (n = 5) or the opposite sequence (n = 5). During the massage therapy period, massage was provided daily for three 15 minute periods at the beginning of each 3 hour period every morning. Metabolic measurements were performed by indirect calorimetry, using the Deltatrac II Metabolic cart.

RESULTS

Energy expenditure was significantly lower in infants after the 5 day massage therapy period (59.6 +/- 3.6 Kcal/Kg/ 24 hours) than after the period without (63.1 +/- 5.4 Kcal/Kg/ 24 hours) (p = 0.05).

CONCLUSIONS

Energy expenditure is significantly lowered by 5 days of massage therapy in metabolically and thermally stable preterm infants. This decrease in energy expenditure may be in part responsible for the enhanced growth caused by massage therapy.

Neonatal nucleated red blood cells in infants of overweight and obese mothers

OBJECTIVE

The perinatal outcome of the infant of obese mother is adversely affected and in theory, may involve fetal hypoxia. We hypothesized that an index of fetal hypoxia, the neonatal nucleated red blood cell (NRBC) count, is elevated in infants of overweight and obese mothers.

STUDY DESIGN

Absolute NRBC counts taken during the first 12 hours of life in 41 infants of overweight and obese mothers were compared to 28 controls.

RESULTS

Maternal body mass index and infant birthweight were significantly higher in the overweight and obese group (P < 0.01). Hematocrit, corrected white blood cell and lymphocyte counts did not differ between groups. The absolute NRBC count was higher (P = 0.01), and the platelet count lower (P = 0.05) in infants of overweight and obese mothers than in controls. In stepwise regression analysis, the absolute NRBC count in infants of overweight and obese mothers remained significantly higher even after taking into account birthweight or gestational age and Apgar scores (P < 0.02).

CONCLUSION

Infants of overweight and obese mothers have increased nucleated red blood cells at birth compared with controls. We speculate that even apparently healthy fetuses of overweight and obese mothers are exposed to a subtle hypoxemic environment.

Increased energy expenditure after dilutional exchange transfusion for neonatal polycythemia

OBJECTIVE

Hypothermia is a known symptom of neonatal polycythemia (NP) and its pathophysiology is unclear. The effect of partial dilutional exchange transfusion (PET) upon resting energy expenditure (REE) is unknown. We aimed to test the hypothesis that PET leads to an increase in REE.

STUDY DESIGN

11 patients with NP who underwent PET and 10 controls without polycythemia were studied. NP was defined as a venous HCT >/=0.65. Per protocol, symptomatic infants and/or those with venous HCT > or =0.70 underwent PET. REE was measured just prior and 23 hours after PET in patients with NP and at identical ages in the control group. Infants were studied in a skin servo controlled radiant warmer, while clinically and thermally stable, prone and asleep. Measurements were stopped during body movements (less than 5% of the time of measurement). Metabolic measurements were performed by indirect calorimetry, using the Deltatrac II Metabolic monitor (Datex-Ohmeda, Helsinki, Finland). This instrument uses the principle of the open circuit system that allows continuous measurements of oxygen consumption (Vo(2)) and carbon dioxide production (Vco(2)) using a constant flow generator. REE measurements were corrected for the infant weight (Kcal/kg/d). Comparison of REE values between groups was performed using paired Wilcoxon ranked test.

RESULTS

Patients with and without NP had nearly identical baseline REE. In patients with NP, REE increased from 44.0 +/- 6.6 Kcal/Kg/d to 48.3 +/- 5.1 Kcal/Kg/d after PET (P<0.05). Furthermore, the increase in REE following PET correlated inversely with the decrease in hematocrit. There was no significant change in REE over time in the control group. In the NP group, symptomatic infants (n=5) had a significantly greater increase in REE following PET than non-symptomatic ones (1.4 +/- 6.3 vs. 7.8 +/- 4.9 Kcal/Kg/d, p<0.05).

CONCLUSIONS

Energy expenditure of polycythemic infants increases following PET, in a manner proportional to the decrease in hematocrit. Symptomatic polycythemic infants have a greater rise in REE following PET than non-symptomatic ones. We speculate that polycythemia leads to a decreased REE that might be remedied by PET.

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.

Changes in energy expenditure in preterm infants during weaning: a randomized comparison of two weaning methods from an incubator

We aimed to compare resting energy expenditure (REE) of infants exposed to either one of two weaning methods and to confirm the increase in REE during weaning from incubator. The study was a prospective randomized clinical trial of weaning preterm infants using either of two methods. REE was measured at baseline and 6, 23, 30, and 47 h, using indirect calorimetry. At measurement, infants were clinically and thermally stable, asleep, 2 h after feeding. Forty-two patients were randomized to "open incubator" (n = 23) or "warming bassinet" (n = 19). The groups did not differ in baseline clinical characteristics. REE increased significantly in both groups within 23 h, and remained stable at 30 and 47 h. At 6 and 23 h, the incubator group had significantly higher increase in REE than the warming bassinet group. By 30 h and at 47 h post-weaning, the REE of both groups became similar. In conclusion, REE increases significantly at weaning from incubator. The warming bassinet delays the increase in REE observed when infants are weaned using a turned off incubator. Whether one method is superior to the other in terms of thermic stress cannot be determined from this study.

Immediate nipple pain relief after frenotomy in breast-fed infants with ankyloglossia: a randomized, prospective study

PURPOSE

Ankyloglossia ("tongue-tie") occurs in nearly 5% of neonates, but its clinical significance relating to breast-feeding difficulties is controversial. We tested the hypothesis that in infants with ankyloglossia referred because of breast-feeding difficulties, frenotomy alleviates the symptoms.

METHODS

Twenty-five mothers of healthy infants with ankyloglossia were recruited because of sore nipples. Infants were randomized to either of 2 sequences: (1) frenotomy, breast-feeding, sham, breast-feeding (n = 14) or (2) sham, breast-feeding, frenotomy, breast-feeding (n = 11). The mothers as well as all personnel taking care of the child after each sham or frenotomy procedure were masked as to the study sequence. In every sequence, and after each sham or frenotomy procedure, a standardized latch score and pain score were obtained from the mother.

RESULTS

There was a significant decrease in pain score after frenotomy than after sham (P = .001). There was also a nearly significant improvement in latch after the frenotomy in these mothers (P = .06).

CONCLUSION

Frenotomy appears to alleviate nipple pain immediately after frenotomy. We speculate that ankyloglossia plays a significant role in early breast-feeding difficulties, and that frenotomy is an effective therapy for these difficulties.

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.

The prevalence of regurgitations in the first 2 days of life in human milk- and formula-fed term infants

PURPOSE

Very little is known about the prevalence of regurgitations in human milk-fed infants in the first days of life. The authors aimed to compare the frequency of regurgitations in formula- and breastfed infants in the first 2 days of life. It was hypothesized that human milk-fed infants experience less episodes of regurgitations than their formula-fed counterparts. DESIGN, SAMPLE, AND OUTCOME VARIABLES: Thirty-two (32) infants were formula fed and 31 were breastfed. In both groups, infants were fed ad libitum, as soon as the mother was ready to feed the infant. All regurgitations were noted on a collection form.

RESULTS

The number of regurgitations per infant in the first 48 hours of life was similar in breastfed (range 0 to 7) and formula-fed infants (range 0 to 8). There was also no difference in the number of regurgitations in the first or second 24-hour period. Eighteen of 31 of infants in the breastfed group and 17/32 in the formula fed groups had at least one episode of regurgitation during the 48-hour period.

CONCLUSIONS

Contrary to this hypothesis, human milk feeding did not confer a "protection" on regurgitations in these young neonates.