Tandem Breastfeeding and Human Milk Macronutrients Content

Introduction: Little is known about the effect of tandem breastfeeding (the practice of breastfeeding two different age siblings) on human milk (HM) macronutrients content. We aimed to study macronutrients and energy content in HM collected during tandem breastfeeding.

Methods: Prospective-observational study. Mothers who breastfed their infants during pregnancy and intended to continue breastfeeding after delivery were recruited (tandem-group) and compared to a group of mothers who did-not breastfed during pregnancy, gave birth and breastfed one infant (control-group). Milk was collected during the last 4-weeks of pregnancy (tandem-group only), at 72-hours (colostrum, both groups) and at 30-days after delivery (mature-HM, both groups). Analysis was by infrared-transmission-spectroscopy.

Results: Fifty healthy-mothers were enrolled, out of which eighteen continued breastfeeding during term-pregnancy and after labor. They were compared to data from 118 mothers who did-not breastfeed during pregnancy and breastfed only one term-infant. HM during pregnancy had significantly lower fat content compared to HM in colostrum and mature-milk from the same mother (2.5±1.4 vs. 2.9±0.9, p=0.003; 2.5±1.4 vs. 4.2±1.2, p=0.009, respectively). Colostrum and mature-milk Fat did-not differ between tandem and controls. Protein during pregnancy was significantly higher compared to colostrum and mature-HM (3.5±1.4 vs. 2.0±0.8, p=0.001; 3.5±1.4 vs. 1.1±0.3, p<0.0001, respectively). Colostrum and mature-HM protein did-not differ between the 2 groups. HM-lactose during pregnancy was significantly lower compared to mature-HM (6.4±1.4 vs. 8.1±0.2, p<0.0001). Colostrum and mature-HM Lactose were significantly higher in tandem-group compared to controls. Energy content during pregnancy was significantly lower compared to mature-HM (63.4±11.4 vs. 71.9±10.0, p=0.047). Colostrum Energy was significantly higher in tandem-group compared to controls.

Conclusion: HM expressed during pregnancy has different macronutrients content compared to HM after regular-full-term pregnancy. After delivery, during tandem-breastfeeding, there are minor differences in lactose and energy only in colostrum. Thus, mothers who tandem-breastfeed can be reassured about the macronutrients content of their milk.