Efficacy of continuous monitoring of maternal temperature during labor using wireless axillary sensors.

Neonatal early onset sepsis (EOS) occurs in 0.5-0.8/1000 live births and is a major cause of morbidity and mortality. Its presenting signs in newborns are non-specific, so risk assessment before birth is essential. Maternal fever during labor is the strongest predictor of EOS, but the current standard is for infrequent manual determinations of temperature. We aimed to determine whether continuous measurement of temperature during labor is feasible, accurate, and more effective than manual measurements for detecting fever. Women were recruited on admission in labor at > 35 weeks gestational age, with < 6 cm cervical dilation. Sensors were affixed in the axilla, which transmitted every 4 minutes by Bluetooth to a dedicated tablet. Conventional temperature measurements were taken every 3-6 hours per routine. Of 336 subjects recruited, 155 had both > 4 hours of continuous data and > 2 manual temperature measurements and were included for analysis. Continuous recordings were feasible and correlated well with manual measurements independent of mean temperature. Of 15 episodes of fever > 38 °C detected by both methods, 13 were detected earlier by continuous (9 of those more than 1 hour earlier). Manual measurements missed 32 fevers > 38 °C and 13 fevers > 38.5 °C that were identified by continuous. Continuous measurement of maternal temperature for the duration of labor is practical and accurate. It may be more sensitive for identifying infants at risk for EOS than the current practice, enabling earlier and more effective targeted treatment of affected infants.

Bacterial stability with freezer storage of human milk.

OBJECTIVES: Human milk supports the development of a beneficial newborn intestinal microflora. We have shown previously that human milk had reduced bacteria but unchanged nutrient composition when stored at -20 °C for up to nine months. We suspected declining bacterial colony counts were manifestations of bacterial dormancy and not failure of survival. We investigated differences in selected bacterial colony counts (lactobacillus, bifidobacteria, staphylococcus, streptococcus and enterococcus) in human milk stored for 2 and 12 weeks at -20 °C in either manual or automatic defrost freezers and whether reduced bacterial counts at 12 weeks were the result of dormancy or failure of survival. METHODS: Freshly expressed milk was obtained from mothers in the NICU, divided into aliquots and stored for 2 and 12 weeks at -20 °C in either automatic or manual defrost freezers. Subsequently, duplicate aliquots, one thawed and the other thawed and maintained at room temperature for 4 h, were plated to assess bacterial colony counts. RESULTS: Significant declines in bacterial colony counts were seen from 2 to 12 weeks freezer storage for all bacteria. There were no differences in colony counts between freezer types. Once thawed, no further bacterial growth occurred. CONCLUSIONS: Short-term freezer storage for 12 weeks resulted bacterial killing. Type of freezer used for storage did not have an impact on bacterial survival. It is unknown whether the paucity of important probiotic bacteria in stored human milk has adverse effects on infants.

Short-term efficacy of two breast pumps and impact on breastfeeding outcomes at 6 months in exclusively breastfeeding mothers: A randomised trial.

The provision of breast pumps is a potential strategy to increase breastfeeding duration. This trial compared the effectiveness and acceptability of two breast pumps in mothers exclusively breastfeeding (EBF) their healthy term infant. It also tested whether provision of pumps versus vouchers of equivalent value influenced breastfeeding or attainment of mothers' goals at 3 and 6 months. Mothers were randomised at 3- to 4-week post-partum (Beijing [n = 30], Moscow [n = 34], London [n = 45], New York [n = 3]) to groups A (Philips single-electric pump, Natural bottle), B (Medela Swing single-electric pump, Calma bottle), or C (Control; vouchers). At 6 weeks, group A and B mothers expressed for 10 min/breast; milk weight and opinions of pump/bottle were recorded. Feeding practices were assessed using questionnaires at 3 and 6 months. Milk weight/flow pattern did not differ between groups. Pump A scored significantly better for ease-of-use, cushion-feel, need-to-lean-forward, pleasant, comfort. At 3 and 6 months, %EBF or meeting their goal was not significantly different; (3 months: 86%, 85%, 84%; 6 months: 20%, 15%, 26%; meeting goal 24%, 17%, 27% for A, B, and C). Expressed breast milk (EBM) provision was higher in groups A and B (3 months: 76%, 76%, 24% (p < 0.001); 6 months: 83%, 87%, 32% (p < 0.001); and negatively predicted EBF at 6 months (OR no EBM 5.07, 95% CI [1.56, 16.5]). The pumps were equally effective for milk expression at 6 weeks. Pump provision did not significantly influence breastfeeding practices or attainment of goals but resulted in higher EBM provision, which was associated with lower EBF but not other breastfeeding categories at 6 months.

Effects of Extended Freezer Storage on the Integrity of Human Milk.

OBJECTIVE: To examine the integrity (pH, bacterial counts, host defense factors, nutrient contents, and osmolality) of freshly expressed and previously refrigerated human milk subjected to long-term freezer storage. STUDY DESIGN: Mothers donated 100 mL of freshly expressed milk. Samples were divided into baseline, storage at -20°C (fresh frozen) for 1, 3, 6, and 9 months, and prior storage at +4°C for 72 hours (refrigerated frozen) before storage at -20°C for 1 to 9 months. Samples were analyzed for pH, total bacterial colony count, gram-positive and gram-negative colony counts, and concentrations of total protein, fat, nonesterified fatty acids, lactoferrin, secretory IgA, and osmolality. RESULTS: Milk pH, total bacterial colony count, and Gram-positive colony counts decreased significantly with freezer storage (P < .001); bacterial counts decreased most rapidly in the refrigerated frozen group. The gram-negative colony count decreased significantly over time (P < .001). Nonesterified fatty acid concentrations increased significantly with time in storage (P < .001). Freezing for up to 9 months did not affect total protein, fat, lactoferrin, secretory IgA, or osmolality in either group. CONCLUSIONS: Freezer storage of human milk for 9 months at -20°C is associated with decreasing pH and bacterial counts, but preservation of key macronutrients and immunoactive components, with or without prior refrigeration for 72 hours. These data support current guidelines for freezer storage of human milk for up to 9 months for both freshly expressed and refrigerated milk.

Prediction of intrapartum fever using continuously monitored vital signs and heart rate variability.

Objectives: Neonatal early onset sepsis (EOS), bacterial infection during the first seven days of life, is difficult to diagnose because presenting signs are non-specific, but early diagnosis before birth can direct life-saving treatment for mother and baby. Specifically, maternal fever during labor from placental infection is the strongest predictor of EOS. Alterations in maternal heart rate variability (HRV) may precede development of intrapartum fever, enabling incipient EOS detection. The objective of this work was to build a predictive model for intrapartum fever. Methods: Continuously measured temperature, heart rate, and beat-to-beat RR intervals were obtained from wireless sensors on women (n = 141) in labor; traditional manual vital signs were taken every 3-6 hours. Validated measures of HRV were calculated in moving 5-minute windows of RR intervals: standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive differences (RMSSD) between normal heartbeats. Results: Fever (>38.0 °C) was detected by manual or continuous measurements in 48 women. Compared to afebrile mothers, average SDNN and RMSSD in febrile mothers decreased significantly (p < 0.001) at 2 and 3 hours before fever onset, respectively. This observed HRV divergence and raw recorded vitals were applied to a logistic regression model at various time horizons, up to 4-5 hours before fever onset. Model performance increased with decreasing time horizons, and a model built using continuous vital signs as input variables consistently outperformed a model built from episodic vital signs. Conclusions: HRV-based predictive models could identify mothers at risk for fever and infants at risk for EOS, guiding maternal antibiotic prophylaxis and neonatal monitoring.

Lipid peroxidation products as predictors of oxidant-mediated disease in preterm infants.

BACKGROUND: Preterm infants are susceptible to "oxygen radical diseases" (ORD). 8-isoprostane (8-IP) is a bioactive eicosanoid generated by reactive oxygen species-catalyzed peroxidation of arachidonic acid. Malondialdehyde (MDA) is generated by the decomposition of oxidant-induced lipid hydroperoxides. We hypothesize that the development of ORD is associated with elevated plasma 8-IP on day 0-1, and increasing urine levels of MDA in the first month. METHODS: Preterm (<32 weeks, n = 39) and term (n = 39) infants were recruited at birth. Plasma 8-IP was quantified by ELISA on day 0-1, and urine MDA by colorimetric assay of thiobarbituric acid reactive substances (TBARS) on days 0-1, 7, 14, 21, and 28. ORD was defined as retinopathy of prematurity ≥ stage 1, pneumatosis, or oxygen requirement at 36 weeks corrected gestational age. RESULTS: Plasma 8-IP was higher on day 0-1 in preterm infants who developed ORD compared to term infants. Urine TBARS levels increased in preterm infants from day 0-1 to day 28 but were not different in infants with or without ORD. Preterm infants who developed ORD demonstrated a significant rise in urine TBARS levels from day 1 to 14. CONCLUSIONS: Elevated plasma 8-IP on day 1 is associated with ORD in preterm infants. If validated as a biomarker for ORD, it may be useful in directing antioxidant therapies to the most susceptible infants. Urine TBARS during the first month are not significantly different in term infants, preterm infants with ORD, and preterm infants without ORD, but rapid rise of TBARS in the first 2 weeks may be associated with ORD.

Refrigerator storage of expressed human milk in the neonatal intensive care unit.

OBJECTIVE: To provide recommendations for refrigerator storage of human milk, the overall integrity (bacterial growth, cell counts, and component concentrations) of milk was examined during 96 hours of storage at 4 degrees C. STUDY DESIGN: Fresh milk samples (n = 36) were divided and stored at 4 degrees C for 0, 24, 48, 72, and 96 hours. At each time, pH, white cell count, and osmolality were measured and additional samples were stored at -80 degrees C until analyzed for bacteria and concentrations of lactoferrin, secretory (s)IgA, fat, fatty acids, and protein. RESULTS: There were no significant changes for osmolality, total and Gram-negative bacterial colony counts or concentrations of sIgA, lactoferrin, and fat. Gram-positive colony counts (2.9 to 1.6 x 10(5) colony-forming units per mL), pH (7.21 to 6.68), white blood cell counts (2.31 to 1.85 x 10(6) cells per mL), and total protein (17.5 to 16.7 g/L) declined, and free fatty acid concentrations increased (0.35 to 1.28 g/L) as storage duration increased, P < .001. CONCLUSIONS: Changes were minimal and the overall integrity of milk during refrigerator storage was preserved. Fresh mother's milk may be stored at refrigerator temperature for as long as 96 hours.

Serum surfactant protein D as a marker for bronchopulmonary dysplasia.

BACKGROUND: Lung epithelial cells express surfactant protein D (SP-D), a calcium-dependent lectin that plays an important role in antibody-independent pulmonary host defense. Previous studies have shown that it is found in the peripheral circulation in patients with pulmonary disease, likely because of translocation into the blood when lung epithelial barriers are disrupted by inflammation or acute injury. In adults, serum SP-D levels are biomarkers for the progression and severity of chronic lung disease. In neonates, elevated SP-D levels in cord blood and on day 1 have been associated with prenatal risk factors and with an increased risk of respiratory distress syndrome and infections. It is not known whether serum SP-D during the first week of life is a marker for bronchopulmonary dysplasia (BPD), a form of chronic lung disease of prematurity that is associated with lung parenchymal maldevelopment and injury. OBJECTIVE: The goal of this study is to determine whether serum SP-D on days 3 and 7 of life are associated with the development of BPD in preterm infants. DESIGN/METHODS: Serum samples were obtained on postnatal days 3 and 7 from 106 preterm infants (500-2000 g birth weight, 23-32-week gestation). SP-D was quantified by Western blot. BPD was determined at 36 weeks PMA using NICHD criteria. RESULTS: The mean birth weight was 1145 ± 347 g and gestational age 29.2 ± 7.4 weeks. BPD was diagnosed in 7 and "BPD or death" in 16 infants. Days 3 and 7 values tracked significantly (r = 0.648), and did not correlate with birth weight or gestational age. Contrary to expectations, serum SP-D was not associated with BPD. Significant gender differences were noted, with SP-D dropping from day 3 to day 7 in males, while increasing in females (p < .05). CONCLUSION: Elevated serum SP-D does not appear to be a useful marker for BPD. Decreasing serum SP-D levels in males, as compared to females, during the first week of life are likely related to gender differences in lung maturation, consistent with the higher incidence of BPD in males.

Pasteurization Preserves IL-8 in Human Milk.

Background: Pasteurized donor human milk is an alternative feeding when mothers' own milk is not available for premature infants. The effects of pasteurization on the host defense properties of human milk are unclear. We investigated the effects of Holder pasteurization on concentrations of anti-inflammatory and pro-inflammatory cytokines in human milk. Objective: To compare concentrations of anti-inflammatory and pro-inflammatory cytokines before and after pasteurization of donor human milk. Study Design: A single milk sample was obtained from each of 24 mothers of premature infants in the neonatal intensive care unit by electric breast pump and was stored at -80°C. At the time of pasteurization, milk samples were thawed and divided into two aliquots. The first aliquot was re-stored at -80°C and the second aliquot was heat-treated at 62.5°C for 30 min and then re-stored at -80°C. At the time of batch cytokine analyses samples were thawed rapidly. Results: Most cytokine concentrations declined following pasteurization. The most prevalent cytokine, IL-8, was preserved (89%) following pasteurization. There were no relationships between gestational age, postnatal age of milk collection, duration of milk storage, and the concentrations cytokines. Conclusion: In contrast to most cytokines after pasteurization, IL-8 is preserved or liberated from another compartment. The maintenance of IL-8 in human milk after pasteurization and the loss of anti-inflammatory cytokines following pasteurization, suggests that the effects of inflammatory activity in pasteurized human milk should be evaluated. These data may account, in part, for the lesser protective effect on the host of pasteurized donor human milk compared with mother's own milk.

Effect of human milk fortifiers on bacterial growth in human milk.

BACKGROUND: As a component in human milk fortifiers (HMF), iron may equilibrate with human milk for as long as 24 hours, bind important bacteriostatic proteins, and potentially affect the host defense properties of human milk. OBJECTIVE: We compared bacterial growth in human milk prepared with each of two HMF differing in their content of iron. STUDY DESIGN: Samples of human milk obtained from mothers of premature infants were divided and mixed with one of two HMF and maintained at refrigerator temperature. Refrigerated milk samples were removed at 0, 24, and 72 hours for determination of total bacterial colony counts (TBCC). RESULTS: TBCC did not differ between groups but declined from 0 to 72 hours, p<0.001. CONCLUSION: These data suggest that differences in iron content, or other nutrients in HMF, do not affect bacterial growth in human milk. Storage of fortified human milk at refrigerator temperature for 72 hours results in decreased bacterial growth. As a component in human milk fortifiers (HMF), iron may equilibrate with human milk for as long as 24 hours, bind important bacteriostatic proteins, and potentially affect the host defense properties of human milk. We compared bacterial growth in human milk prepared with each of two HMF differing in their content of iron. Samples of human milk obtained from mothers of premature infants were divided and mixed with one of two HMF and maintained at refrigerator temperature. Refrigerated milk samples were removed at 0, 24, and 72 hours for determination of total bacterial colony counts (TBCC).

Oral Feeding Assessment Predicts Length of Hospital Stay in Late Preterm Infants.

BACKGROUND: When compared with term infants, late preterm (LP) infants have greater morbidity and mortality, longer hospital stay, and greater rate of hospital readmission. Oral feeding difficulty is one of the prominent reasons for delayed discharge in LP infants. OBJECTIVE: To identify the maturity levels of LP infants' oral feeding skills (OFS) at the time of their first oral feeding and to determine the relationship between OFS maturity levels and length of hospital stay. METHODS: OFS was assessed in 48 LP infants born between 340/7 and 356/7 weeks gestational age at the time of their first oral feeding within 24 h of birth. The intake at 5 minutes, at completion of the feeding, and the duration of feeding a 15 mL prescribed volume of milk were tabulated. Proficiency expressed as percent mL consumed in the first 5 min/15 mL prescribed and rate of milk transfer over the entire feeding (mL/min) were recorded. OFS were assessed using a novel 4-level scale defined by the combined proficiency and rate of milk transfer. RESULTS: When compared with their 35-week counterparts, infants born at 34 weeks gestation had poorer OFS profiles (p = 0.035) and longer hospital stay (p < 0.001). Additionally, further analyses demonstrated that, independently, LOS was associated negatively with both GA and OFS. CONCLUSION: Assessment of OFS levels in LP infants at their first oral feeding can help identify infants at risk of oral feeding issues that may delay hospital discharge. For those infants, we speculate that provision of evidence-based efficacious interventions that improve OFS may shorten hospital stay and decrease hospital re-admissions.