Fortified Pasteurized Donor Milk for Very-low-birth-weight Infants

Generic names: Human donor milk; donor milk banking

In 2007, the Cochrane Collaboration published a systematic review of literature through May 2007 that included eight randomized controlled trials (RCTs) comparing formula feeding and donor breast milk in preterm low-birth-weight (LBW) infants.1 This analysis reported that donor milk feeding resulted in a lower rate of short-term growth and a lower risk of developing necrotizing enterocolitis (NEC) compared with formula feeding.1 Most of the studies were published in the 1980s, and only one of the included eight RCTs used fortified pasteurized donor milk, which limits applicability of these results to current clinical practice. Thus, this report's focus is using fortified pasteurized donor milk as a supplement to or replacement for a mother's breast milk for feeding her very-low-birth-weight (VLBW) infant. An infant's birth weight and gestational age highly correlate with the infant's chance of survival, according to the Institute of Medicine.2 Birth weights between 2,500 g (5 lb, 8 oz) and 3,997 g (8 lb, 13 oz) are considered normal.3 LBW infants weighing less than 2,500 g (5 lb, 8 oz) are further classified as VLBW (i.e., weight <1,500 g 3 lb, 5 oz) and extremely LBW infants (i.e., weight <1,000 g 2 lb, 3 oz).3 Preterm birth (i.e., <37 weeks gestation) typically causes LBW; however, poor fetal growth can also cause LBW, usually because of problems with the placenta, maternal health, or birth defects. In cases of poor fetal growth, full-term infants can be very small and physically immature.3 Risk factors associated with VLBW infants include the following:3-5

VLBW infants who survive are "at significantly increased risk of severe long-term health and developmental problems, including physical and sensory difficulties, developmental delays, and cognitive impairment."3,5 Possible complications associated with VLBW include the following:3,4

Nutritional impairment, which can cause slow rates of weight gain, may result from gut immaturity/delayed motility, delayed enteral feeding (i.e., feeding through tube placed in the stomach or upper small bowel), inability to nipple feed, and increased caloric needs. VLWB infants are also at increased risk of developing NEC.6 This serious intestinal condition affects 5% to 10% of infants weighing <1,500 g (3 lb, 5 oz) in the first several weeks of life and causes necrosis of the intestinal wall lining. Sepsis, peritonitis, intestinal stricture, or perforation can result and require surgical intervention. Mortality commonly occurs from NEC and can be as high as 30% in VLBW neonates.6,7 Of infants who survive NEC, about half develop a long-term gastrointestinal complication (i.e., short-gut syndrome, intestinal stricture).6,7 Furthermore, NEC is associated with worse long-term neurodevelopmental outcomes and greater health services utilization than similar preterm infants without NEC.8 Parenteral (intravenous) nutrition is typically given to VLBW infants until they attain sufficient enteral feeding. In general, neonatologists prefer human milk for enteral nutrition. However, mothers of VLBW infants are sometimes unable to provide breast milk at all or in sufficient quantities.9,10 These women may experience lingering complications from pregnancy, anxiety regarding the infant's health, lack of privacy that curtails initiation of milk expression, and dislike of breast pumps, as well as the demands of daily travel to the neonatal intensive care unit (NICU) from home or work after delivery.11 One option in these cases is to use milk donated by other lactating mothers as a supplement or replacement.12 However, for VLBW infants, human milk provides insufficient amounts of many nutrients, including protein, carbohydrate, minerals, vitamins, and electrolytes.13-15 Thus, fortification is necessary to promote adequate growth and bone mineralization in these infants, and fortifying human milk has been commonplace in NICUs for more than 25 years.1,8,13,15 Purported benefits of using fortified pasteurized donor milk rather than specialty preterm formula are as follows:

Potential risks associated with using donor milk, in general, include maternal disease transmission, pathogen or drug contamination of the milk, potentially slower growth compared with preterm formula, and a reduced incentive for mothers to breastfeed and provide their own milk.16Also, pasteurization's effect on donated human milk components has been studied, and reductions in various bioactive components (i.e., immunomodulatory proteins, immunoactive cytokines, growth factors) have been reported.17,18,19

Overall, the rate of VLBW infants born in the United States is increasing because of greater numbers of multiple births and older mothers with complex health histories giving birth to premature infants.8,20 The U.S. Centers for Disease Control and Prevention (CDC) reported that 1.5% of infants had VLBW in 2006.21 In the same year, mortality in VLBW infants was 240 per 1,000 live births.20

According to a 2012 global action report, 15 million babies are born preterm each year and more than 1 million children die each year due to complications of preterm birth; preterm birth rates are increasing in almost all countries that report reliable data.22

Pasteurized human donor milk comes primarily from two sources: the Human Milk Banking Association of North America (HMBANA) and Prolacta Bioscience, Inc. (Monrovia, CA, USA). HMBANA is a nonprofit organization that receives donated human milk, provides screening, and then distributes the donor human milk to various requestors (mostly NICUs). HMBANA charges fees to cover costs of its pasteurized donor milk at its milk banks, but these milk banks often rely on donations to stay solvent. Prolacta is a for-profit company that collects milk from lactating mothers at designated...