Weight loss and body temperature changes in breast-fed and bottle-fed neonates

Exclusive breast feeding and dehydration fever in newborns during the first days of life

Objectives: To determine the prevalence of dehydration fever in infants admitted to the Neonatal Intensive Care Unit (NICU) from the well newborn nursery with fever in the first days of life.Study design: Retrospective data analysis of term infants admitted to the NICU from the well newborn nursery with fever (n = 75). Infants were divided into two groups based on hydration status using clinical and laboratory signs of dehydration. Clinical and laboratory variables were compared between the two groups.Results: Fifty-three of the 75 infants admitted to the NICU with fever had clinical and laboratory signs of dehydration (71%). Infants with dehydration were more likely to be exclusively breast fed and present with fever at >24 h of age. There were no positive blood or cerebrospinal fluid cultures in infants with dehydration. The incidence of dehydration fever increased after implementation of an "Exclusive Breast Feeding" policy from 1.4/1000 to 3.5/1000 live births (p ≤ .01).Conclusions: Dehydration is associated with fever in exclusively breast fed infants during the first several days of life. There were no cases of serious bacterial or viral infections in the cohort of febrile infants with clinical and laboratory signs of dehydration.

Estimation of fat-free mass in Asian neonates using bioelectrical impedance analysis

The aims of this study were to develop and validate a prediction equation of fat-free mass (FFM) based on bioelectrical impedance analysis (BIA) and anthropometry using air-displacement plethysmography (ADP) as a reference in Asian neonates and to test the applicability of the prediction equations in an independent Western cohort. A total of 173 neonates at birth and 140 at two weeks of age were included. Multiple linear regression analysis was performed to develop the prediction equations in a two-third randomly selected subset and validated on the remaining one-third subset at each time point and in an independent Queensland cohort. FFM measured by ADP was the dependent variable, and anthropometric measures, sex and impedance quotient (L2/R50) were independent variables in the model. Accuracy of prediction equations was assessed using intra-class correlation and Bland-Altman analyses. L2/R50 was the significant predictor of FFM at week two but not at birth. Compared with the model using weight, sex and length, including L2/R50 slightly improved the prediction with a bias of 0·01 kg with 2 sd limits of agreement (LOA) (0·18, -0·20). Prediction explained 88·9 % of variation but not beyond that of anthropometry. Applying these equations to the Queensland cohort provided similar performance at the appropriate age. However, when the Queensland equations were applied to our cohort, the bias increased slightly but with similar LOA. BIA appears to have limited use in predicting FFM in the first few weeks of life compared with simple anthropometry in Asian populations. There is a need for population- and age-appropriate FFM prediction equations.

Breastfeeding and neonatal weight loss in healthy term infants

BACKGROUND

Neonatal weight loss is universally recognized, yet poorly understood. Limited professional consensus exists on the definition of lower limit of safe weight loss.

OBJECTIVE

Our aim was to assess the extent of neonatal weight loss and its association with selected clinical variables in a population of healthy term infants cared for using a specific protocol on weight loss.

METHODS

We retrospectively considered 1003 infants consecutively admitted to the regular nursery of the Institute for Maternal and Child Health "Burlo Garofolo" (Trieste, Italy). We studied the relationship of selected variables with neonatal weight loss recorded during the hospital stay. We also analyzed all readmissions in the first month of life as a result of weight loss and its complications.

RESULTS

We observed a mean absolute weight loss of 228 g ± 83g, and a mean percent weight loss of 6.7% ± 2.2%. Weight loss ≥ 10% and > 12% were 6% and 0.3%, respectively. In multivariate logistic regression, cesarean section, hot season, any formula feeding, and jaundice not requiring phototherapy were independently associated with neonatal weight loss ≥ 8%. Conversely, low gestational age status was associated with lower weight loss. Readmission within the first month of life because of dehydration occurred in 0.3% of infants.

CONCLUSIONS

Breastfeeding, compared to formula feeding, may not be a risk factor for greater early neonatal weight loss, at least in contexts in which weight is routinely monitored, breastfeeding is repeatedly assessed and appropriately supported, and careful supplementation is prescribed to limit and promptly treat excess weight loss and its related complications.

Fetal Laboratory Medicine: On the Frontier of Maternal–Fetal Medicine

BACKGROUND

Emerging antenatal interventions and care delivery to the fetus require diagnostic support, including laboratory technologies, appropriate methodologies, establishment of special algorithms, and interpretative guidelines for clinical decision-making.

CONTENT

Fetal diagnostic and therapeutic interventions vary in invasiveness and are associated with a spectrum of risks and benefits. Fetal laboratory assessments are well served by miniaturized diagnostic methods for blood analysis. Expedited turnaround times are mandatory to support invasive interventions such as cordocentesis and intrauterine transfusions. Health-associated reference intervals are required for fetal test interpretation. Fetal blood sampling by cordocentesis carries substantial risk and is therefore performed only when fetal health is impaired, or at risk. When the suspected pathology is not confirmed, however, normative fetal data can be collected. Strategies for assurance of sample integrity from cordocenteses and confirmation of fetal origin are described. After birth, definitive assessment of prenatal environmental and/or drug exposures to the fetus can be retrospectively assessed by analysis of meconium, hair, and other alternative matrices. A rapidly advancing technology for fetal assessment is the use of fetal laboratory diagnostic techniques that use cell-free fetal DNA collected from maternal plasma, and genetic analysis based on molecular counting techniques.

SUMMARY

Developmental changes in fetal biochemical and hematologic parameters in health and disease are continually delineated by analysis of our collective outcome-based experience. Noninvasive technologies for fetal evaluation are realizing the promise of lower risk yet robust diagnostics; examples include sampling and analysis of free fetal DNA from maternal blood, and analysis of fetal products accessible at maternal sites. Application of diagnostic technologies for nonmedical purposes (e.g., sex selection) underscores the importance of ethical guidelines for new technology implementation.

Duration of breastfeeding associated with obesity during adolescence

The relationship between duration of breastfeeding and obesity (body mass index > or = 85 percentile) at adolescence was investigated in a white, rural population (n = 136) in which confounding by race was absent and confounding by socioeconomic status was expected to be minimal. Relevant data were abstracted from hospital charts. When examined independently, minimal (< or = 2 months) or no breastfeeding was positively associated with adolescent obesity (p < 0.03). This association was present in the lower but not the higher socioeconomic status group. However, when sex, birthweight, and socioeconomic status were included in a multiple regression model, duration of breastfeeding was no longer significantly associated with obesity during adolescence.

Assessing fluid and electrolyte status in the newborn

Fluid and electrolyte assessment during the first week of life is complicated by rapid changes in fluid and electrolyte balance during the transition from fetal to neonatal life and by the newborn’s small size. A physiologic decrease in extracellular water volume, as well as a transient increase in serum potassium and transient decreases in plasma glucose and total plasma ionized calcium concentrations must be taken into account. In general, the more immature the newborn, the greater the changes that can be expected. The use of plasma creatinine as an indicator of glomerular filtration rate is limited because it is a function of maternal renal function at birth and because of non-steady-state conditions in the immediate postnatal period. Guidelines for monitoring schedules are provided on the basis of these physiologic considerations and the author’s experience. Method of blood sampling and time to separation of serum are important considerations in interpreting results. Minimization of sample volume is critical to minimize blood transfusion requirements. Clinicians should be aware of the analytical error associated with these measurements in their own institutions. Reference ranges are provided.