Inadequate Content of Docosahexaenoic Acid (DHA) of Donor Human Milk for Feeding Preterm Infants: A Comparison with Mother's Own Milk at Different Stages of Lactation

Abstract

A cross-sectional single-center study was designed to compare the fatty acids profile, particularly docosahexaenoic acid (DHA) levels, between milk banking samples of donor human milk and mother's own milk (MOM) for feeding preterm infants born before 32 weeks' gestation. MOM samples from 118 mothers included colostrum (1-7 days after delivery), transitional milk (9-14 days), and mature milk (15-28 days and ≥29 days). In the n-3 polyunsaturated fatty acids (PUFAs) group, the levels of α-linolenic acid (C18:3 n3) and DHA (C22:6 n3) showed opposite trends, whereas α-linolenic acid was higher in donor human milk as compared with MOM, with increasing levels as stages of lactation progressed, DHA levels were significantly lower in donor human milk than in MOM samples, which, in turn, showed decreasing levels along stages of lactation. DHA levels in donor human milk were 53% lower than in colostrum. Therefore, in preterm infants born before 32 weeks' gestation, the use of pasteurized donor human milk as exclusive feeding or combined with breastfeeding provides an inadequate supply of DHA. Nursing mothers should increase DHA intake through fish consumption or nutritional supplements with high-dose DHA while breastfeeding. Milk banking fortified with DHA would guarantee adequate DHA levels in donor human milk.

Keywords: docosahexaenoic acid; donor human milk; preterm infants.

Figure 1

Differences in n-3 PUFAs between donor human milk (grey bar) and colostrum of mothers of preterm infants of <32 weeks’ gestation) (black bar). Donor human milk showed higher levels of α-linolenic acid (C18:3 n3, +43.4%) and about −53.0% lower levels of docosahexaenoic (DHA) acid (C22:6 n3). Asterisks indicate significant differences (*** p < 0.001) between the different groups.

Figure 2

(A) The stearic acid (C18:0) and the oleic acid (C18:1 n-9) showed quite symmetrical but opposite trends in mothers’ own milk (MOM) during the different stages of lactation. Donor human milk (DHM) showed a significantly higher content of stearic acid and lower content of oleic acid (colostrum 1–7 days, transitional milk 8–14 days, mature mild 15–28 days and ≥29 days). (B) In MOM samples, α-linolenic acid (C18:3 n3) and DHA (C22:6 n3) showed a different and opposite pattern increasing and decreasing from colostrum to transitional milk, respectively. Arachidonic acid (AA) (C20:4 n6) levels in MOM samples decreased from colostrum to mature milk. Donor human milk is markedly deficient in DHA content. Asterisks indicate significant differences (* p < 0.05; ** p < 0.01; *** p < 0.001) in each group vs. DHM sampling points.

Figure 3

Main fatty acid ratios changes between colostrum (black bar) and human donor milk (grey bar). Asterisks indicate significant differences (* p < 0.05; ** p < 0.01; **** p < 0.0001) in each group among sampling points (SFA: saturated fatty acids; MUFA: monounsaturated fatty acids; PUFA: polyunsaturated fatty acids; n-6 LPUFA: n-6 long chain polyunsaturated fatty acids; LA: linoleic acid; n-3 LCPUFA: n-3 long chain polyunsaturated fatty acids; ALA: α-linoleic acid).