No abstract

Although breast milk is the normative feeding for infants, breastfeeding rates are lower than recommended. We investigated breastfeeding difficulties experienced by mothers in the first months after delivery and their association with early breastfeeding discontinuation. We conducted a prospective observational study. Mothers breastfeeding singleton healthy term newborns at hospital discharge were enrolled and, at three months post-delivery, were administered a questionnaire on their breastfeeding experience. Association among neonatal/maternal characteristics, breastfeeding difficulties and support after hospital discharge, and type of feeding at three months was assessed using multivariate binary logistic regression analysis. We enrolled 792 mothers, 552 completed the study. Around 70.3% of mothers experienced breastfeeding difficulties, reporting cracked nipples, perception of insufficient amount of milk, pain, and fatigue. Difficulties occurred mostly within the first month. Half of mothers with breastfeeding issues felt well-supported by health professionals. Maternal perception of not having a sufficient amount of milk, infant’s failure to thrive, mastitis, and the return to work were associated with a higher risk of non-exclusive breastfeeding at three months whereas vaginal delivery and breastfeeding support after hospital discharge were associated with a decreased risk. These results underline the importance of continued, tailored professional breastfeeding support.

Key PointsQuestionIs chorioamnionitis a risk factor for developing bronchopulmonary dysplasia in preterm infants?FindingsThis systematic review, meta-analysis, and metaregression found that chorioamnionitis was associated with an increased risk of bronchopulmonary dysplasia in preterm infants but also found significant differences in baseline characteristics between infants with and infants without chorioamnionitis. A multivariate metaregression model combining the difference in gestational age and the odds of respiratory distress syndrome was associated with 64% of the variance in the association between chorioamnionitis and bronchopulmonary dysplasia.MeaningExposure to chorioamnionitis is associated with a higher risk of developing bronchopulmonary dysplasia in preterm infants, but this association may be modulated by gestational age and risk of respiratory distress syndrome.

AimsThe mechanisms involved in hypoxic pulmonary vasoconstriction (HPV) are not yet fully defined. The aim of the study was to determine the role of protein kinase C ζ (PKCζ) and neutral sphingomyelinase (nSMase) in HPV.Methods and resultsCeramide content was measured by immunocytochemistry and voltage-gated potassium channel (KV) currents were recorded by the patch clamp technique in isolated rat pulmonary artery smooth muscle cells (PASMC). Contractile responses were analysed in rat pulmonary arteries mounted in a wire myograph. Pulmonary pressure was recorded in anesthetized open-chest rats. Protein and mRNA expression were measured by western blot and RT–PCR, respectively. We found that hypoxia increased ceramide content in PASMC which was abrogated by inhibition of nSMase, but not acid sphingomyelinase (aSMase). The hypoxia-induced vasoconstrictor response in isolated pulmonary arteries and the inhibition of KV currents were strongly reduced by inhibition of PKCζ or nSMase but not aSMase. The nSMase inhibitor GW4869 prevented HPV in vivo. The vasoconstrictor response to hypoxia was mimicked by exogenous addition of bacterial Smase and ceramide. nSMase2 mRNA expression was ∼10-fold higher in pulmonary compared with mesenteric arteries. In mesenteric arteries, hypoxia failed to increase ceramide but exogenous SMase induced a contractile response.ConclusionnSMase-derived ceramide production and the activation of PKCζ are early and necessary events in the signalling cascade of acute HPV.