Variation in maternal lactation practices associated with changes in diurnal maternal inflammation.

Area of Science:

• Immunology
• Human lactation research
• Postpartum physiology

Background:

• The role of human milk in infant immunity is recognized, but maternal immune system changes due to at-the-nipple (ATN) breastfeeding remain understudied.
• Lactation's evolutionary purpose includes supporting infant survival and enhancing maternal fitness, suggesting potential immune benefits for the mother.

Purpose of the Study:

• To investigate the impact of ATN breastfeeding on maternal immune status by examining diurnal changes in salivary cytokines and C-reactive protein (CRP).
• To explore how different infant feeding methods, including ATN breastfeeding and pumping, correlate with maternal immune responses.

Main Methods:

• Collecting data on infant feeding practices (ATN breastfeeding, pumping, donated milk, supplementation) from postpartum women in Seattle, WA.
• Utilizing Bayesian modeling to estimate the effects of ATN breastfeeding on the diurnal secretion rates of pro-inflammatory salivary cytokines (e.g., IL-8) and CRP.

Main Results:

• Most mothers employed diverse feeding methods, with pumping being a common alternative to ATN breastfeeding.
• ATN breastfeeding demonstrated non-linear associations with diurnal IL-8 and CRP secretion rates.
• Significant differences in diurnal CRP patterns were observed between women practicing zero versus ubiquitous ATN breastfeeding.

Conclusions:

• Maternal lactation practices, specifically the extent of ATN breastfeeding, are linked to variations in maternal immune responses.
• Viewing lactation as a continuous variable offers a more nuanced understanding of postpartum maternal physiology and immune function.