Table 3.

Fatty acid compositions of phospholipid-rich lipids in human milk

Fatty acid	Relative mass proportions in phospholipid-rich lipids					Quantities as phosphatidylcholine (mg/mL)
	Low cortisol (<  3 nmol/L)		High cortisol (>  10 nmol/L)		p-value	Low cortisol (<  3 nmol/L)		High cortisol (>  10 nmol/L)		p-value
	Mean	STDEV	Mean	STDEV		Mean	STDEV	Mean	STDEV
Lauric 12:0	2.16	1.04	2.50	1.38	0.29a	0.03	0.02	0.03	0.02	0.63a
Myristic 14:0	4.01	1.38	4.87	1.77	0.01a,b	0.05	0.03	0.05	0.03	0.37a
Myristoleic 14:1n − 5	0.16	0.11	0.16	0.09	0.99a	0.002	0.002	0.002	0.001	0.59a
Palmitic 16:0	21.55	3.04	21.70	3.25	0.81c	0.23	0.14	0.21	0.10	0.96a
Palmitoleic 16:1n − 7	1.96	0.63	1.88	0.70	0.57c	0.02	0.02	0.02	0.01	0.53a
Stearic 18:0	13.20	4.14	13.07	3.83	0.81a	0.12	0.06	0.12	0.05	0.52a
Oleic 18:1n − 9	31.30	6.62	30.13	5.98	0.23a	0.37	0.29	0.32	0.20	0.61a
Vaccenic 18:1n − 7	1.68	0.32	1.63	0.34	0.43c	0.02	0.02	0.02	0.01	0.58a
Linoleic 18:2n − 6	14.81	2.68	14.94	2.72	0.77a	0.15	0.09	0.15	0.07	0.69a
Linolenic 18:3n − 3	1.44	0.58	1.49	0.57	0.98a	0.02	0.02	0.02	0.01	0.77a
Arachidic 20:0	0.18	0.08	0.19	0.07	0.69a	0.002	0.001	0.002	0.001	0.81a
Gondoic 20:1n − 9	0.63	0.16	0.65	0.15	0.37a	0.007	0.004	0.006	0.004	0.88a
Eicosadienoic 20:2n − 6	0.30	0.07	0.33	0.07	0.06c	0.003	0.002	0.003	0.002	0.89a
Dihomogammalinolenic 20:3n − 6	0.85	0.32	0.86	0.33	0.98a	0.008	0.004	0.008	0.004	0.52a
Arachidonic 20:4n − 6	1.83	0.79	1.92	0.99	0.90a	0.02	0.01	0.02	0.01	0.70a
Eicosatrienoic 20:3n − 3	0.02	0.04	0.01	0.04	0.27a	0.000	0.001	0.000	0.001	0.22a
Eicosapentaenoic 20:5n − 3	0.29	0.16	0.26	0.15	0.26a	0.003	0.002	0.003	0.002	0.29a
Behenic 22:0	0.03	0.04	0.03	0.04	0.93a	0.000	0.001	0.000	0.001	0.93a
Docosenoic 22:1n − 9	0.11	0.08	0.17	0.11	0.009a,b	0.001	0.001	0.001	0.001	0.11a
Nervonic 24:1n − 9	1.02	0.69	0.92	0.39	0.93a	0.01	0.01	0.01	0.01	0.48a
Docosahexaenoic 22:6n − 3	0.05	0.33	0.06	0.28	0.69a	0.000	0.001	0.000	0.001	0.71a
Other fatty acids	2.43	0.81	2.24	0.70	0.11a	0.03	0.02	0.02	0.01	0.50a
SAFA	41.13	5.01	42.37	5.15	0.23c	0.43	0.25	0.41	0.18	0.99a
MUFA	35.83	7.17	34.62	6.50	0.20a	0.43	0.33	0.37	0.22	0.61a
PUFA	19.59	3.63	19.86	3.67	0.53a	0.20	0.12	0.19	0.10	0.72a
Omega-3 FAs	1.80	0.63	1.82	0.61	0.89a	0.02	0.02	0.02	0.01	0.70a
Omega-6 FAs	17.79	3.54	18.04	3.51	0.52a	0.18	0.10	0.17	0.09	0.65a
	Relative mass proportion of polar lipids from all lipids
	3.28	1.43	2.89	1.19	0.16a

Data is presented as relative proportions (%) and quantities (mg/mL) and grouped based on milk cortisol levels. Statistically significant differences (p < 0.05) between low and high milk cortisol groups are highlighted with bold type. Abbreviations: STDEV standard deviation, SAFA saturated fatty acids, MUFA monounsaturated fatty acids, PUFA polyunsaturated fatty acids

^a Significant difference between the low and high cortisol groups, Mann–Whitney U test

^b Milk cortisol (as continuous variable) remained a statistically significant predictor after controlling for pre-pregnancy BMI and sampling time in linear regression analysis, see Additional file 1

^c Significant difference between the low and high cortisol groups, T-test (df = 98)