Evidence of human milk oligosaccharides in maternal circulation already during pregnancy: a pilot study

Am J Physiol Endocrinol Metab. 2019 Mar 1;316(3):E347-E357. doi: 10.1152/ajpendo.00320.2018. Epub 2018 Nov 13.


Human milk oligosaccharides (HMOs) are bioactive glycans linked with health benefits to both the breast-fed infant and lactating mother. We hypothesized that HMOs are present before lactation, already during pregnancy, and are influenced by maternal body composition. In a pilot study, we investigated individual and temporal variations in HMO composition and concentration in maternal serum at gestational weeks 10-14 ( visit 1), 20-24 ( visit 2), and 30-35 (visit 3) (V1, V2, and V3, respectively) and associations with maternal body composition. HMOs were quantified by HPLC and confirmed by enzymatic digest and mass spectrometry. Associations of maternal prepregnancy body mass index (BMI), subcutaneous adipose tissue (SAT) thickness, and adipokines with absolute and relative HMO concentrations were analyzed by Spearman correlation. We identified 16 HMOs and 2 oligosaccharides not common to human milk. HMO concentration and composition varied with gestational age and secretor status. HMO concentration increased with gestational age and changed from a predominantly sialylated profile at V1 to a more balanced fucosylated-to-sialylated ratio at V3, mostly due to a profound increase in 2'-fucosyllactose (2'-FL), reflecting secretor phenotype. In secretor-positive women, BMI was negatively correlated with 2'-FL at V2. SAT at V1 and V2 were strongly negatively correlated with 2'-FL concentrations. This pilot study shows that prenatal HMOs are present in maternal serum, suggesting roles for HMOs already during pregnancy. Our result that maternal body composition is associated with prenatal HMOs might indicate that maternal metabolism modulates HMO composition with unknown implications for maternal and fetal health already during pregnancy.

Keywords: 2′-fucosyllactose; human milk oligosaccharides; metabolic programming; pregnancy; secretor status; subcutaneous adipose tissue.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipokines / blood*
  • Adiponectin / blood
  • Adult
  • Body Composition
  • Body Mass Index
  • Chromatography, High Pressure Liquid
  • Chromatography, Liquid
  • Cohort Studies
  • Female
  • Gestational Age
  • Humans
  • Leptin / blood
  • Longitudinal Studies
  • Milk, Human*
  • Oligosaccharides / blood*
  • Organ Size
  • Pilot Projects
  • Pregnancy / blood*
  • Pregnancy Trimester, First
  • Pregnancy Trimester, Second
  • Pregnancy Trimester, Third
  • Prospective Studies
  • Subcutaneous Fat / anatomy & histology
  • Tandem Mass Spectrometry


  • Adipokines
  • Adiponectin
  • Leptin
  • Oligosaccharides