The Importance of Human Milk in Preterm Infants

Almerinda Barroso Pereira

Hospital de Braga

The Importance of Human Milk in Preterm Infants

• Premature infants have great nutritional needs to achieve optimal growth in the neonatal period.

– Infants born at the beginning of the third trimester of pregnancy often are growth-restricted because of decreased intrauterine nutrient deposition.

– Medical conditions: hypotension, hypoxia, acidosis, infection, surgery, increase metabolic energy requirements and nutrient needs .

– Additional impediments to growth are physiologic immaturity of the gastrointestinal tract including decreased gastrointestinal motility and reduced intestinal enzyme activity.

The Importance of Human Milk in Preterm Infants

• Nutritional support helps to correct growth restriction at birth and to achieve an appropriate rate of weight gain.

• Enteral nutrition must be provided to premature infants with human milk as the preferred feeding for all infants.

Pediatrics. 2012;129(3):e827

ADVANTAGES OF HUMAN MILK

• Improved gastrointestinal function, digestion, absorption of nutrients.

• Promotes more rapid attainment of full enteral feeds.

• Improved host defence with reduced rates of infection.

• Enhanced maternal psychological well-being and maternal-infant bonding.

• Shorter duration of hospitalization in premature infants.

• Improved cognitive and visual development.

• Breastfeeding is associated with long-term benefits , infant and mother.

www.ahrq.gov/downloads/pub/evidence/pdf/brfout/brfout.pdf (October 2008)

Human Milk

• Clinical Direct Benefits:

– Improvement in Gastrointestinal Function

– Host Defence - Anti-microbial Components

• Long – Term Benefits:

– Reduction of Acute Illnesses

– Decreased Risk of Chronic Diseases

– Improved Neurodevelopment Outcome

Human Milk and Gastrointestinal Function

Components of human milk stimulate gastrointestinal growth

and motility, which enhance the maturity of the gastrointestinal tract:

– Cortisol, somatomedin-C, insulin-like growth factors, insulin, and thyroid hormone may affect intestinal growth and mucosal function.

– Growth factors (nerve growth factor) may play a role in the innervation of the intestinal tract .

– Gastrointestinal mediators (neurotensin and motilin) may affect gastrointestinal motility.

– Free amino acids may be trophic for intestinal growth (taurine) and may stimulate enterocyte growth (glutamine).

Clin Perinatol. 1999;26(2):335.

Human Milk and Gastrointestinal Function

• Components of human milk are protective and decrease the risk of infections:

• Growth factors (epidermal growth factor) affect development of the intestinal tract and may be protective against invasive disease.

– Human milk is associated with neonatal intestinal colonization by the beneficial microbes of the Bifidobacteria and Lactobacilli species rather than potential enteropathogenic bacteria.

– Anti-inflammatory agents, Enzymes, Immunoglobulins IgA and IgG, protective agents..

Am J Physiol Gastrointest Liver Physiol. 2005;288(4):G755.

Acta Paediatr. 2004;93(11):1496.

Arch Dis Child Fetal Neonatal Ed. 2011;96(3):F160

Compared to formula, human milk has been shown to:

• Increase the rate of gastric emptying.

• Increase the intestinal lactase activity in premature infants.

• Decrease the risk of NEC in premature infants.

Human Milk Improved Host Defense - Reduced Rates Infection

• Presence of maternal antibodies ([IgG] [sIgA]) in breast milk provided by the enteromammary immune system.

• Mothers exposed to their own infants by skin-to-skin contact may also make specific antibodies to nosocomial pathogens.

• Human milk feeding may result in fecal flora comprised of less pathogenic microorganisms than nursery-acquired pathogens.

Human Milk Anti-microbial Components

• Human milk contains a variety of heterogeneous agents that possess antimicrobial activity:

– Protein: lactoferrin, lysozyme, serum immunoglobulin A.

– Lipid: free fatty acids and monoglycerides, lipase.

– Carbohydrate: oligosaccharides .

– White blood cells: neutrophils and macrophages, lymphocytes in human milk may contribute to cytokine production (T-cells) or Ig A production (B-cells).

JAMA. 2009;302(13):1421 Pediatr Res. 2006;59(3):377.

Human Milk - Reduce Acute Illnesses

• A study of former premature infants demonstrated that infants who received human milk had fewer days of upper respiratory symptoms compared to those who were formula-fed during the first seven months of life (17.6 vs 38 days).

• The incidence of sepsis is reduced in premature infants receiving human milk.

J Perinatol. 2002;22(5):354.

Human Milk - Decrease Risk of Chronic Diseases Adult Cardiovascular Disease • In a randomized trial, adolescents born preterm who

received human milk compared to those who received formula had a lower serum C-reactive protein (CRP) and a lower ratio of low density lipoprotein (LDL) to high density lipoprotein (HDL) cholesterol, indicative of a lower risk for cardio vascular disease.

Lancet. 2004;363(9421):1571.

Neurodevelopment Outcome

• Improved long-term cognitive development in premature infants has been reported with the receipt of human milk during hospitalization, including extremely low birth weight (ELBW) infants.

• Breastfeeding is associated with improved cognitive development, particularly in children born preterm.

• The benefit of breastfeeding upon cognitive function is modulated by variations of a gene involved in the control of fatty acid metabolism. (FADSE2 gene)

Pediatrics. 2007;120(4):e953.

Proc Natl Acad Sci U S A. 2007;104(47):18860

J Pediatr. 2012;160(1):25...

Visual function • Several studies have indicated that human milk-fed term and

premature infants have improved visual function compared to formula-fed infants.

• This benefit has been attributed to docosahexaenoic acid (DHA), which is a component of phospholipids found in brain, retina, and red cell membranes.

• The severity and incidence of retinopathy of prematurity are decreased among breastfed compared to formula fed infants.

• This association may relate to the substantial antioxidant capacity of human milk compared with formula.

Pediatr Int. 2007;49(6):894.

J Pediatr. 2008;152(3):356.

Hearing function

• Infants fed breast milk have faster brainstem maturation, compared with infants fed formula, based on the rate of maturation of brainstem auditory-evoked responses in preterm infants .

• This effect may be attributable to the constituent composition of breast milk, compared with

synthetic formulas.

Pediatrics. 2000;106(2 Pt 1):318

Stress Reduction

• There appears to be an analgesic effect of breastfeeding, which may be due to the enhanced maternal-infant bonding.

• Breastfed infants experience less stress during painful procedures than formula fed infants.

• The lactation hormones, oxytocin and prolactin, are important components of the stress axis and have a positive impact on social behaviors, including maternal-infant bonding.

• Another possible explanation for the analgesic effect of breastfeeding is a higher cortisol level in breast-fed compared to formula-fed infants.

• Improved bonding may reduce infant stress.

BMJ. 2003;326(7379):13.

J Pediatr. 2009;154(3):452

• Human Milk is strongly supported because of its acknowledged direct benefits to nutrition, gastrointestinal function, host defense, and psychological well-being.

• There is increasing evidence that human milk has long-term benefits beyond the period of breastfeeding. These include continued protection against acute illnesses, and reported reduction of specific chronic diseases.

• Human Milk also may have improved neurodevelopmental outcome compared to those who were formula-fed.

Human Milk is the Best in Preterm Infants