Breast milk fat content of mothers to small-for-gestational-age infants

Little is known about the composition of human milk (HM) expressed by mothers of asymmetrically growth-restricted infants. To test the null hypothesis that lactating mothers of small-for-gestational-age (SGA) infants produce milk with fat content similar to that of lactating mothers of infants whose growth is appropriate for gestational age (AGA).

Fifty-six lactating mothers of newborns (26 SGA and 30 AGA) were recruited within the first 3 days of delivery. Creamatocrit (CMT) levels in HM were measured at 72 h, 7 days and 14 days postdelivery in capillary tubes after centrifugation at 9000 r.p.m. for 5 min.

The groups did not differ in terms of maternal age, body mass index, gestational age (GA), pregnancy weight gain and parity. They differed significantly in terms of infant's birth weight by design. The mean CMT levels at the three time points were similar for the two groups. This remained true when timing of the sample (colostrum, transitional, mature milk) was introduced as a confounder in the analysis of variance (general linear model).

Fat content of HM is not affected by fetal growth status. We suggest that mothers of SGA infants may be reassured that their milk contains adequate amount of fat that is appropriate for the growth of their infants.