Table 3.

Meta-analysis results of preterm and term breast milk energy content over time from measured and calculated estimates

Comparison: Bomb calorimetry energy measurement (kcal/dL)♦
	Preterm			Term			Preterm & term compared
Time frame:	mean	SD	n	Mean	SD	n	% difference	p-value
d 1-3	49	7	12	54	8	19	−10	0.34
d 4-7	71	9	52	66	9	37	7	0.02
week 2	71	12	53	66	9	34	7	0.04
week 3-4	77	8	27	66	8	97	16	< 0.00001*
week 5-6	70	5	14	63	7	40	11	< 0.00001*
week 7-9	76	8	11	63	7	77	21	< 0.00001*
week 10-12	-	-	-	63	8	83	-	-
Energy meta-analysis was limited to 24 hour collections
♦ References: [11,12,18,119-126]
Comparison: Calculated energy content (kcal/dL)♦♦
	Preterm			Term			Preterm & term compared
Time frame:	mean	SD	n	Mean	SD	n	% difference	p-value
d 1-3	-	-	-	-	-	-
d 4-7	65	13	41	68	9.6	48	−5	0.21
week 2	70	14	95	-	-	-
week 3-4	68	8.0	135	70	9.3	46	−2	0.26
week 5-6	67	6.9	79	-	-	-
week 7-9	66	8.9	63	69	9.9	43	−4	0.16
week 10-12	66	14	14	68	9.0	95	−3	0.50
♦♦ References: [6,19,22,121,127]
Comparison: Measured vs. calculated energy
	Preterm		Term
	Difference	% difference	p-value	Difference	% difference	p-value
d 1-3		-	-		-	-
d 4-7	6	−9%	0.009	−2	2%	0.350
week 2	1	−2%	0.66
week 3-4	9	−11%	< 0.00001*	−3	5%	0.007
week 5-6	3	−5%	0.11
week 7-9	10	−13%	0.0009*	−6	9%	0.0003*
week 10-12				−5	9%	0.0002*

*Statistically significant difference. In compensation for multiple comparisons, an approximate Bonferroni adjustment was made and the p-value for statistical significance was < 0.001.