Maternal Predictors of Breast Milk Plasmalogens and Associations with Infant Body Composition and Neurodevelopment

Purpose: Ethanolamine-containing plasmalogens (pPEs) are a unique class of breastmilk (BM) glycerophospholipids containing a vinyl-ether at the sn-1 and a polyunsaturated fatty acid (PUFA) at the sn-2 position of the glycerol moiety. pPEs are present in the milk fat globule membrane, accumulate in the infant brain, and have been implicated in infant development. The study objectives were to: (1) describe the composition of BM pPEs and the variation in monomers at both the sn-1 and sn-2 positions; and (2) quantify the associations between BM pPEs and maternal predictors (body mass index, race, dietary fatty acid intake, gestational age at birth, and days' postpartum). Secondary objectives were to explore the relationship between BM pPEs and infant anthropometrics and neurodevelopment.

Methods: This was a secondary analysis of 39 mother-infant dyads in the control group of a randomized controlled trial of vitamin D supplementation during lactation. BM samples and data regarding maternal diet, infant anthropometrics (weight, fat mass index, and fat-free mass index by dual-energy X-ray absorptiometry), and infant development were collected at 1 month (visit 1 [V1], n = 37) and 4 months' (visit 4 [V4], n = 39) postpartum. BM pPEs were extracted and quantified by using ultra-HPLC/high-resolution MS/MS at V1 and V4 and expressed as percent mass of total phospholipids. Associations of pPEs with infant development and anthropometrics were modeled using linear regression.

Findings: C(18:0) vinyl ethers and C(18:2) polyunsaturated fatty acid-enriched pPEs predominate in BM. Specific pPEs, as a proportion of total phospholipids, decreased between V1 and V4. Higher maternal body mass index was associated with lower BM pPEs in unadjusted models, but this association was attenuated after adjustment for race, diet, and days' postpartum. Maternal fatty acid intake, gestational age, and days' postpartum were not associated with BM pPEs. Total pPEs at V1 were negatively associated with infant fat mass index and positively associated with fat-free mass index at V1 and V4. BM pPE concentrations were not correlated with neurodevelopmental outcomes.

Implications: BM pPEs decrease over lactation and are associated with lower infant adiposity and higher lean mass.

Clinicaltrials: gov identifier: NCT00412074.