Effect of Donor Milk Supplementation on Breastfeeding Outcomes in Term Newborns: A Randomized Controlled Trial

BACKGROUND

Pasteurized donor human milk (DHM) use for healthy newborns is increasing; however, no studies have explored its effect on breastfeeding outcomes.

PATIENTS AND METHODS

We enrolled 60 healthy, term breastfeeding newborns with ≥4.5% weight loss in the first 36 hours in a randomized controlled trial. Thirty newborns were randomly assigned to early limited-volume DHM supplementation and 30 newborns to exclusive breastfeeding. Mothers were surveyed at 1 week and 1, 2, and 3 months regarding the mode of infant feeding. Comparing infants randomized to DHM supplementation with those exclusively breastfeeding, there was no significant difference in the proportion using formula at 1 week (21% vs 7%, P = .15), nor in the proportion of any breastfeeding (79% vs 90%, P = .30) or breastfeeding without formula at 3 months (62% vs 77%, P = .27). Conclusion For newborns with ≥4.5% weight loss in the first 36 hours, early limited-volume supplementation with DHM is unlikely to have a significant favorable impact on breastfeeding outcomes.

Evaluation of hematologic variables in newborn C57/BL6 mice up to day 35

BACKGROUND

Hematologic variables are often analyzed in animal analogs during the investigation of complex disease etiologies such as necrotizing enterocolitis. However, reference intervals (RI) can vary depending on animal strain, age, and sampling site. Reference intervals have been published for adult C57BL/6J mice, but not newborn C57BL/6J mice.

OBJECTIVES

The purpose of the present study was to determine hematologic RI in newborn C57BL/6J mice up to day 35.

METHODS

C57BL/6J mice founders from The Jackson Laboratory were bred at the University of Iowa. Blood samples were obtained via facial vein sampling at postnatal days 0 (p0), p7, p14, p21, p28, or young adulthood (p35). CBCs were determined with the Sysmex XT-2000iV analyzer within 30 minutes of blood collection at a 1:10 dilution. Statistics were determined using nonparametric methods following ASVCP guidelines.

RESULTS

Hematologic RI were determined for each of the 6 groups (n = 247, n ≥ 39 per group). Significantly higher values for HGB, RBC, and PLT counts were observed with advancing developmental age. Total WBC counts remained relatively stable during the first 35 days of life. However, WBC differential counts were dominated by neutrophils and lymphocytes in the younger mice, with a trend toward a lymphocytic leukogram on day 35.

CONCLUSIONS

These results illustrate the dynamic changes in hematologic variables during murine development after birth. Utilization of age-specific RI is advised when evaluating data derived from experimental perinatal mouse models.

Genetic variants associated with severe retinopathy of prematurity in extremely low birth weight infants

PURPOSE

To determine genetic variants associated with severe retinopathy of prematurity (ROP) in a candidate gene cohort study of US preterm infants.

METHODS

Preterm infants in the discovery cohort were enrolled through the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network, and those in the replication cohort were from the University of Iowa. All infants were phenotyped for ROP severity. Because of differences in the durations of enrollment between cohorts, severe ROP was defined as threshold disease in the discovery cohort and as threshold disease or type 1 ROP in the replication cohort. Whole genome amplified DNA from stored blood spot samples from the Neonatal Research Network biorepository was genotyped using an Illumina GoldenGate platform for candidate gene single nucleotide polymorphisms (SNPs) involving angiogenic, developmental, inflammatory, and oxidative pathways. Three analyses were performed to determine significant epidemiologic variables and SNPs associated with levels of ROP severity. Analyses controlled for multiple comparisons, ancestral eigenvalues, family relatedness, and significant epidemiologic variables. Single nucleotide polymorphisms significantly associated with ROP severity from the discovery cohort were analyzed in the replication cohort and in meta-analysis.

RESULTS

Eight hundred seventeen infants in the discovery cohort and 543 in the replication cohort were analyzed. Severe ROP occurred in 126 infants in the discovery and in 14 in the replication cohort. In both cohorts, ventilation days and seizure occurrence were associated with severe ROP. After controlling for significant factors and multiple comparisons, two intronic SNPs in the gene BDNF (rs7934165 and rs2049046, P < 3.1 × 10(-5)) were associated with severe ROP in the discovery cohort and were not associated with severe ROP in the replication cohort. However, when the cohorts were analyzed together in an exploratory meta-analysis, rs7934165 increased in associated significance with severe ROP (P = 2.9 × 10(-7)).

CONCLUSIONS

Variants in BDNF encoding brain-derived neurotrophic factor were associated with severe ROP in a large candidate gene study of infants with threshold ROP.

Hyperglycemia as a risk factor for the development of retinopathy of prematurity

BACKGROUND

Hyperglycemia has recently been described as a risk factor for the development of retinopathy of prematurity (ROP), a proliferative vascular disease of the retina that primarily affects premature infants. This study was to evaluate the relationship of hyperglycemia and the development of ROP in premature infants less than 32 weeks gestation.

METHODS

This was a retrospective cohort study of all infants less than 32 weeks gestation from 2003-2007 who survived to discharge in our NICU. Demographic data including birthweight, gestational age, Apgar scores, method of delivery, antenatal steroid use, neonatal steroid use, and size for gestational age was collected for each infant. Episodes of sepsis, grade of intraventricular hemorrhage, presence of a patent ductus arteriosus, number of days on the ventilator, and stage of necrotizing enterocolitis were assessed as well as days of hyperglycemia, defined as number of days with whole blood glucose > 150 mg/dl. In addition, the highest stage of ROP was recorded for each infant. A Student's two tailed t-test or Fisher's exact test was performed to identify significant clinical risk factors associated with the development of ROP. From this univariate analysis, a multiple logistic regression was performed to determine the effect of hyperglycemia on the development of ROP, adjusting for significant clinical risk factors. Statistical analysis was performed using SAS v.9.2.

RESULTS

Univariate analysis demonstrated that infants with ROP were of lower birthweight and gestational age, and were affected by a patent ductus arteriosus, neonatal sepsis, intraventricular hemorrhage, have significant lung disease and received postnatal glucocorticoid therapy. Infants with ROP experienced more days with hyperglycemia (7 vs. 2, p = < 0.0001). Using multiple logistic regression analysis to compare no ROP vs. all stages of ROP, gestational age (OR 0.745, 95% CI [0.634, 0.877], p = 0.0004), mean days of hyperglycemia (OR 1.073, 95% CI [1.004, 1.146], p = 0.04), and mean days receiving mechanical ventilation (OR 1.012, 95% CI [1.000, 1.025], p = 0.05) remained significantly associated with ROP after adjusting for other risk factors.

CONCLUSION

Our data suggests that hyperglycemia is associated with the development of ROP in premature infants.

Long-chain polyunsaturated fatty acid levels in US donor human milk: meeting the needs of premature infants?

OBJECTIVE

To determine fatty acid levels in the US donor milk supply.

STUDY DESIGN

Donor human milk samples from Iowa (n=62), Texas (n=5), North Carolina (n=5) and California (n=5) were analyzed by gas chromatography. Levels in the Iowa donor milk were compared before and after pasteurization using Student's t-test. Docosahexaenoic acid (DHA) and arachidonic acid (ARA) levels were compared among all milk banks using analysis of variance.

RESULT

ARA (0.4 pre, 0.4 post, P=0.18) and DHA (0.073 pre, 0.073 post, P=0.84) were not affected by pasteurization. DHA varied between banks (P<0.0001), whereas ARA did not (P=0.3). DHA levels from all banks were lower than published values for maternal milk and infant formula (P<0.0001).

CONCLUSION

Pasteurization of breastmilk does not affect DHA or ARA levels. However, DHA content in US donor milk varies with bank location and may not meet the recommended provision for preterm infants.