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The hypothesis that neonatal nucleated red blood cell (RBC) counts are elevated in nondiscordant twins compared with singletons is studied. It was found that concordant, appropriate-for-gestational age twins have increased nucleated RBCs at birth as compared to singleton control infants.

The authors have investigated the hypothesis that specific markers of fetal hypoxia would be increased in infants whose mothers have asthma. The results are reported.

Placing a newborn baby on its mother's abdomen immediately after delivery can increase the amount of fetal blood cells that can be used for transplantation. Fetal blood contains cells called stem cells, which are the precursor of all other blood cells. These cells can be transplanted into many patients instead of bone marrow. The cells could be collected from cord blood, which is normally discarded. In a study of 49 deliveries, 22 infants were placed on their mother's abdomen and 27 were held below this level. Researchers were able to collect more cord blood from the babies placed on their mother's abdomen.

Polycythemia in newborn babies may a sign that the baby had low blood levels of oxygen before birth, according to a study of 66 newborn babies. Polycythemia means the baby had more red blood cells than normal. This study showed that babies with polycythemia had more nucleated red blood cells than normal. These are immature blood cells, and their presence in greater than normal amounts is a sign of increased red blood cell production. This normally occurs when oxygen levels decrease.

Infants who are born in hospital maternity wards are usually fed on fixed schedules during their stay. These hospital feeding schedules are necessary where it is not possible to have the mother and infant rooming together because of staffing constraints. Feeding schedules have been criticized for interfering with mother-infant bonding. This study was done to identify any differences between infants who were breast-fed every three hours and those breast-fed every four hours during their first three days of life. Some recent studies have reported that infants who feed more frequently consume more milk and have greater growth during the first month. A more frequent schedule is also reported to be more beneficial to the mother, who experiences less breast tenderness and nipple soreness. The results of this study involving 152 newborns did not indicate that feeding the infants every four hours increased the normal transitional weight loss experienced by all breast-fed newborns. The infants who fed less frequently also did not have higher circulating bilirubin (a red blood cell breakdown product) levels than the more frequently fed infants, which had been a concern reported in an earlier study, as this could contribute to jaundice in susceptible newborns. This study found that a four-hour versus three-hour hospital feeding regimen does not have adverse effects on infant weight loss or bilirubin levels. But this study did not investigate whether feeding on demand (feeding whenever the infant appears hungry, without a set schedule) would be better than either of these hospital feeding schedules. (Consumer Summary produced by Reliance Medical Information, Inc.)

AbstractObjective:The prevalence of a lingual frenulum in newborn infants is reportedly 0.3–12%. The purpose of this study was to describe the prevalence of a lingual frenulum based on the Coryllos classification in nonselected newborn infants after delivery, hypothesizing that it is higher than the values reported in the literature.Study Design:The lingual frenula of 200 healthy infants were evaluated by visual examination and palpation within the first 3 days after delivery. The frenulum was categorized according to the four Coryllos classifications. Each infant's mother responded, immediately after the examination, to a structured questionnaire on the quality and type of feeding. An additional structured telephone interview with the 179 breastfeeding mothers was conducted 2 weeks later.Results:All but one infant (n=199) had an observable or palpable lingual frenulum that was Coryllos type 1 (n=5), type 2 or 3 (n=147), or type 4 (n=47). Although our study was not powered enough to test for any correlation between the cessation of breastfeeding and the type of frenulum, we found no statistical correlation between the Coryllos type of lingual frenulum and the presence of breastfeeding difficulties.Conclusions:A lingual frenulum is a normal anatomical finding whose insertion point and Coryllos classification are not correlated with breastfeeding difficulties. We suggest that the term “lingual frenulum” should be used for anatomical description and that the term “tongue-tie” be reserved for a lingual frenulum associated with breastfeeding difficulties in newborns.

AbstractIntroduction:Breastfeeding difficulties are sometimes attributable to tongue-tie with short-term relief after frenotomy. Limited follow-up is available, and predictors for nonsuccessful frenotomy have not yet been found.Patients and Methods:We recruited 264 mother–infant dyads who underwent lingual frenotomy for breastfeeding difficulties. Data regarding the indications, anatomy of the tongue, and the response of the infant were noted by the physician. Mothers were contacted by telephone at 2 weeks, 3 months, and 6 months after frenotomy to answer a questionnaire.Results:Two weeks after frenotomy, 89% of mothers were still breastfeeding. An improvement in breastfeeding was reported by three-quarters of the mothers, but, unexpectedly, 3% reported worsening. At 3 and 6 months after the procedure, 68% and 56% of mothers were still breastfeeding, respectively. We could not find any predictor to indicate those infants in whom breastfeeding would not improve.Conclusions:There are favorable long-term effects of frenotomy on breastfeeding. Lingual frenotomy does not always alleviate breastfeeding difficulties, and rarely worsening ensues. We could not find any predictor for successful breastfeeding after frenotomy. We speculate that because the procedure is minor, in the event of breastfeeding difficulties, lingual frenotomy should be considered as an effective tool to assist in long-term breastfeeding.

AbstractBackground: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 (R2=0.11, p=0.006) and inversely with GA (R2=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 (R2=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.

Methadone maintenance treatment (MMT) is the standard treatment of choice for pregnant opiate addicts; however, data on newborn outcomes are contradictory. We studied the effect of the timing of starting MMT and of MMT related drug abstinence on the outcome of newborns of former and current opiate-addicted pregnant women.

Objective. To test the hypothesis that intestinal fat losses and energy expenditure (EE) are lower in preterm infants (PTIs) supplemented with medium-chain triglyceride (MCT) oil than in those supplemented with canola oil (CO). Design/Methods. A total of 6 PTIs were studied in a randomized, crossover design. Gestational age was 28 to 34 weeks, and birth weight was 920 to 1269 g. Infants were randomized to supplementation with either 34 kcal (4 g) CO per kg per day or 34 kcal (4.4 g) MCT oil per kg per day for 3 days followed by 3 days of the other oil. EE was measured at baseline, after 3 days of the first oil supplementation, and after 3 days of the alternate oil supplementation based on indirect calorimetry. Also, 72-hour stool samples were collected. Results. The coefficient of added fat absorption was 99.5% ± 0.9% of the MCT oil versus 90.0% ± 16.2% of the CO (P = .056). EE increased after CO supplementation by 4.33 ± 5.96 kcal/kg/d and by 4.17 ± 3.97 kcal/kg/d after MCT (nonsignificant). Thus, after correction for net additional energy intake, energy retained from 34 kcal/kg of added fat was 26.1 ± 6.9 kcal/kg/d after CO and 30.1 ± 5.0 kcal/kg/d after MCT (P = .09). Conclusions. MCT oil may be better absorbed than CO in growing PTIs. The metabolic cost of absorption of MCT oil and CO are similar.

AbstractBackground: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.

The objective of this study was to quantify energy wasted when canola oil (CO) is added to the diet of preterm infants. Eight preterm infants were studied; gestational age ranged from 27 to 33 weeks, and birth weight ranged from 800 to 1317 g. Each infant was studied at baseline for 3 days of stool collection, at the end of which energy expenditure (EE) was measured 1 hour after meals. Each infant was then supplemented with 3 g CO/kg/d for 3 days, after which the study was repeated. Stools were collected for fat analysis. EE increased from 58 ± 6.8 to 62.4 ± 4.6 kcal/kg/24 hours after introduction of CO (P < .03). Stool fat increased from 1.37 ± 1.2 to 2.18 ± 1.2 g/kg/d. Of the fat added, 27% was lost in stools, and 17% was wasted as spent energy. The increase in EE correlated significantly with the coefficient of fat absorption (R2= 0.56, P = .029). In conclusion, the addition of CO to the diet of preterm infants leads to net energy storage of more than half of the extra energy administered and may be an inexpensive alternative to medium-chain triglyceride oil.

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 ≥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 (Vo2) and carbon dioxide production (Vco2) 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.

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.

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.

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” (n23) or “warming bassinet” (n19). 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.

ObjectiveThe 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.MethodsThe 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.ResultsMean 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 (R2 0.28, p< 0.0001).ConclusionsCircadian 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.

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.

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.

Patent ductus arteriosus is a risk factor for the development of necrotizing enterocolitis. The use of indomethacin to treat patent ductus arteriosus in preterm infants may either decrease the incidence of necrotizing enterocolitis by stabilizing or closing the ductus arteriosus or increase its incidence by a direct constricting effect on mesenteric blood vessels. The authors sought to evaluate the interrelationship between patent ductus arteriosus, treatment with indomethacin and the risk of necrotizing enterocolitis in very low birth weight infants. The Israel National database includes prospectively collected data on 99% of all very low birth weight infants in Israel. The study population comprised 6146 infants of 24‐34 weeks' gestation born between 1995 and 2000. The effect of patent ductus arteriosus on necrotizing enterocolitis was assessed using multiple regression analysis. Necrotizing enterocolitis occurred in 5.5% (n = 343) of all infants, in 9.4% of infants with patent ductus arteriosus and in 8.9% of infants who received indomethacin. The occurrence of necrotizing enterocolitis was independently associated with the presence of patent ductus arteriosus among infants not treated with indomethacin (odds ratio, 1.85) and those who received indomethacin therapy (odds ratio, 1.53). Indomethacin therapy in absence of patent ductus arteriosus was not associated with an increased risk of necrotizing enterocolitis (odds ratio, 0.72). Patent ductus arteriosus is an independent risk factor for the development of necrotizing enterocolitis in very low birth weight infants. Therapy with indomethacin did not have a significant effect on the risk for necrotizing enterocolitis.

To evaluate whether the absolute nucleated red blood cell (RBC) count is higher in infants who had meconium aspiration with respiratory symptoms compared with infants with asymptomatic meconium aspiration and controls.

Objective:To test the hypothesis that continuous gastric infusion (CGI) is better tolerated than intermittent gastric bolus (IGB) in small very low birth weight (VLBW) infants.Design:Two-center, prospective, randomized, unmasked clinical trial.Patients:28 VLBW infants (birth weight <1250 g). A strict feeding protocol was followed.Intervention:Patients were randomized to IGB or CGI.Main outcome measures:Time to reach full feeds (160 cc/kg/d)(by design and real), daily weight, caloric intake, residual gastric volume and type of feeding (formula vs.human milk vs.both).Results:Five infants failed to complete the study because of death (n = 4) or protocol violation (n = 1). The two groups did not differ by birth weight or gestational age; infants fed via IGB reached full feeds earlier (p= 0.03) and had less delay in reaching full feeds than infants fed via CGI.Conclusion:Contrary to our hypothesis, gravity IGB is more effective than CGI in improving feeding tolerance in small VLBW infants.

AbstractObjective:This study aimed to evaluate the effect of milk expression method (manual expression versus electric pump) on the composition of breastmilk.Study Design:Data on 21 mothers of 21 newborns 48–72 hours postdelivery were collected and analyzed. The women were randomly assigned to express breastmilk manually followed by pump, or in reverse order. The fat, carbohydrate, and protein contents of the milk samples were analyzed using a human milk analyzer (Miris AB, Uppsala, Sweden).Results:The fat and energy contents of milk obtained through manual expression were higher than those obtained by pump (p=0.024 and p=0.04, respectively, by the Wilcoxon signed rank test). There were no significant differences in protein or carbohydrate content of milk obtained by either method of expression. The difference in fat content between milk obtained by the two methods was not correlated with mother's age, delivery method, gestational age at delivery, parity, or the interval between delivery and the time the sampled milk was obtained.Conclusions:Manually expressed human milk had higher fat content than milk expressed by electric pump. We speculate that this difference is due to the presence of hindmilk in the manually expressed milk because the technique of massaging the breast during manual expression is more likely than the pump to eject hindmilk, which has been shown to have higher fat content than foremilk.

Objective: To evaluate whether the absolute nucleated red blood cell (RBC) count is elevated in term, appropriate for gestational age (AGA) infants born to smoking women.

Deep body temperature is an important and accepted index of health status in newborn infants. There are no easily used accurate methods for continuous deep body temperature measurements. Oral and tympanic membrane temperatures correlate well with rectal temperature but are not easily adapted to continuous measurement. We devised a noninvasive transcutaneous temperature sensor for continuous deep body temperature measurement that relies on the principle that, under steady state conditions, the temperature at the thermally insulated surface of a warm body, i. e. a zero heat loss surface, will be in equilibrium with the warmest part of the body. We used a standard clinical temperature probe placed between the skin and the mattress and attached to the skin with a foam adhesive disk. We used standard skin temperature probe attachment disks, which are also designed to provide thermal insulation to the skin temperature probe. We tested the hypothesis that this transcutaneous temperature would track body temperature as indicated by rectal temperature. In six anesthetized (pentobarbital) newborn piglets (1600 ± 200 g) placed on their abdomen in a convectively warmed infant incubator, we measured continuously the following temperatures for 5 h: transcutaneous over lower and upper abdomen, brown fat, rectal, and descending aorta. To examine the influence of environment, we varied the incubator air temperature between 32° and 36°C. Both transcutaneous temperatures tracked the rectal temperature, within 0.2°C for transcutaneous over lower abdomen and within 0.3°C for transcutaneous over upper abdomen. Aortic artery temperature was always lower than rectal. We conclude that transcutaneous temperature has the potential to be used reliably as a noninvasive replacement for continuous rectal temperature monitoring.

Neonatal hyponatremia can be caused by increased sodium losses, inadequate sodium intake, increased maternal or neonatal water load or by water retention secondary to excess of ADH release. Cocaine use by pregnant women has not as yet been reported to correlate with hyponatremia in the newborn infant. We present a case of an infant whose mother used cocaine regularly during the last stages of pregnancy and who developed hyponatremia in the first week of life. A mechanism is proposed and discussed.

ABSTRACT: Persistent pulmonary hypertension of the newborn (PPHN) often requires extracorporeal membrane oxygenation (ECMO), during which time pulmonary vascular resistance gradually declines. Nitric oxide (NO) is a recently recognized pulmonary vasodilator, but its role in PPHN is unknown. We tested the hypothesis that the concentrations of the urinary metabolites of NO, i.e. nitrite and nitrate, are reduced in patients with PPHN and increase during ECMO as the PPHN resolves. Eight newborn infants with PPHN on ECMO were studied. Daily urinary concentrations of nitrite/nitrate were measured. We found that mean urinary concentrations of nitrite/nitrate were lower in patients with PPHN than in 47 controls without pulmonary disease (p < 0.005). Urinary nitrite/nitrate concentration showed an initial increase after initiation of ECMO. However, a decrease to concentrations still lower than controls occurred on the day before decannulation. We conclude that intrinsic NO production is significantly lower in patients with PPHN than in controls but increases with oxygenation. We speculate that decreased urinary NO metabolite concentrations imply a role for NO deficiency in the pathogenesis of PPHN.

Of 10,122 singleton babies born from January 1, 1984 to March 31, 1988, we compared 1,154 term infants with high serum bilirubin levels (>12.9 mg/dl) to 1,154 infants with low serum bilirubin levels (<12.9 mg/dl) randomly selected from the remaining 8,968 subjects. We found that a high bilirubin level was significantly associated with male sex; maternal diabetes (chronic and gestational); pregnancy-induced hypertension; previous sibling with neonatal jaundice; delivery by cesarean section, vacuum, or forceps; epidural anesthesia; mother with blood type O; first delivery; cephalohematoma; short gestation; lower birth weight; and lower birth order (p< 0.01); and older maternal age, low percentile for birth weight, and the percentage of weight loss during hospitalization (p< 0.05). Variables with significantly different frequencies in control and study groups were used in a multivariate analysis, thus further refining the data by the use of logistic regression. Teenage mothers (<19 years old) had the lowest risk, whereas older mothers (>35 years old) had the highest risk of all age groups for having an infant with neonatal jaundice. First delivery and previous sibling with neonatal jaundice were also risk factors. Male sex, short gestation, and delivery by vacuum extraction were other notable risk factors. Our results suggest that, even among industrialized Western societies, risk factors may interact differently to produce higher neonatal serum bilirubin levels. The importance of a risk factor may also be dependent upon its relative prevalence in a parturient population.

Eicosanoids, derivatives of arachidonic acid, play a role in several inflammatory diseases of the bowel. To determine whether prostaglandin E2(PGE2), leukotriene B4(LTB4), and leukotriene C4D4E4(LTC4D4E4), have a role in hypoxic insult to the intestine, we examined the levels of these mediators in a hypoxic neonatal rabbit model. One group of animals underwent hypoxic insult postnatally, the second group did not undergo hypoxia and served as a control. The levels of PGE2, LTB4, and LTC4D4E4were determined by radioimmunoassay. PGE2in the hypoxic group was 1,779± 142 pg/mg protein (mean± SD) as opposed to 2,380± 197 pg/mg protein in the control group (p < 0.02). LTB4level was 5,446± 3,492 pg/mg protein in the hypoxic rabbits and 3,362± 2,570 pg/mg protein in the control group (p < 0.03). There was no statistically significant difference in the level of LTC4D4E4between the two groups. Our study shows that hypoxia shifts the arachidonic acid metabolism toward enhanced lipoxygenase activity with a resultant increase in LTB4levels and a concomitant decrease in cyclooxygenase activity with reduced PGE2levels in the bowel. The shift in the balance between these eicosanoids may play a role in the pathogenesis of ischemic-hypoxic bowel diseases by enhancing the inflammatory response in the intestine, and simultaneously, diminishing cytoprotection.

AbstractBackground: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.

Objective:In the first days of life, breast-fed infants consume minimal amounts of milk; this may be explained by substrate limitation (limited milk output) and/or by self-limitation (through low appetite and/or suck-swallow competency). The spontaneous milk intake of unrestricted formula-fed infants has not been studied to date. We compared the spontaneous formula intake of unrestricted formula-fed infants to that of breast-fed infants over the first 48 hours of life. We hypothesized that 1) spontaneous formula intake of unrestricted infants is much higher than that of breast-fed infants and 2) spontaneous formula intake correlates positively with gestational age or birthweight.Methods:We studied 43 healthy, term infants. By maternal choice, 15 infants were exclusively breast-fed and 28 were formula-fed ad libitumevery four hours. Breast-fed infants were weighed before and one hour after initiation of feeding, and intake was calculated from the difference between the measurements and corrected individually for the infant’s normal postnatal decrease in body weight. Bottles offered to formula-fed infants contained 60 cc, and the remainder was carefully measured. Intakes were expressed as cc/kg/d, and weight changes as % of birthweight. Statistical methods included Student’s ttests and stepwise regression analysis.Results:Breast feeding on Day 1 was 9.6±10.3 (mean±SD) vs.18.5±9.6 cc/kg/d in formula-fed infants (p=0.011); on Day 2 it was 13.0±11.3 vs.42.2±14.2 cc/kg/d (p<0.001). Breast-fed infants lost significantly more weight on Day 2 (p=0.015). In multiple regression, when the dependent variable was the second-day intake, the significant independent variables were group (higher intake in the formula-fed group), weight loss (the higher the weight loss, the lower the intake), and first-day intake (the higher the first-day intake, the higher the second-day intake).Conclusion:Newborn infants offered formula ad libitumevery four hours consumed much larger amounts than breast-fed infants fed according to the same schedule. In addition, weight loss was more marked in breast-fed infants on Day 2 of life.