Effects of maternal subclinical mammary inflammation on infant growth
Breastfeeding is unquestionably the best nourishment for infants. Current epidemiological as well as experimental evidence has repeatedly demonstrated the nutritional, immunological, and psychosocial benefits attributable to breastfeeding. However, suboptimal breast health may compromise maternal ability to breastfeed and the well-being of breastfeeding infants. Subclinical mastitis (SCM) is an asymptomatic inflammatory condition of the lactating breast that is associated with a number of adverse outcomes including lactation failure, infant growth faltering during the early postpartum period, and increased risk of mother-to-child transmission of the human immunodeficiency virus (HIV).;Three studies were carried out in Ghana with the overall aim of describing the mechanistic pathway(s) linking SCM and infant growth faltering. The specific objectives of the studies were to determine: (1) the prevalence of SCM among lactating women in Ghana, (2) whether SCM is associated with reduced breast milk intake by the infant, and (3) whether SCM occurring beyond the third month postpartum had an adverse effect on infant growth between the third and sixth month postpartum. Two cross-sectional studies were designed with respect to the first two objectives. Data were collected in a longitudinal study to examine the third objective.;All data from the three studies were collected from infant-mother pairs residing in the Eastern region of Ghana. Maternal data included demographic, health, and anthropometric data as well as breast milk samples that were analyzed to determine maternal SCM status. Maternal SCM was primarily diagnosed as elevated breast milk sodium:potassium ratio (Na/K) above 1.0. California mastitis test (CMT) was also used in the cross-sectional studies to diagnose SCM. Infant breast milk intake was estimated using the test weighing procedure. Infant data included feeding, health, and growth measured as weight, length, head circumference, and mid-upper arm circumference.;In the first cross-sectional study, SCM (Na/K > 1.0) was observed among 45.3% of women at three or four months postpartum. About 30% of the observed SCM occurred in only one breast. In the second cross-sectional study, infants whose mothers had Na/K > 1.0 as well as CMT score ≥ 1 had significantly lower breast milk intake (-88.9 g; 95% CI: -171.1 g, -6.9 g). However, the observed milk intake difference across SCM groups disappeared when infant weight and feeding frequency were controlled in multivariate analyses. The longitudinal study did not find an association between maternal episodes of SCM (Na/K) occurring between the 3rd and 6th month postpartum and infant growth occurring during the same period.;In conclusion, our results indicate that SCM is a common condition among women in the Eastern region of Ghana. However, we did not find a reduction in breast milk intake of infants whose mothers had SCM. There was, also, no association between maternal SCM occurring between the 3rd and 6th postpartum and infant growth during the same period.