Maternal and fetal stress are associated with impaired lactogenesis in humans.

Studies in animals indicate that various types of stressful stimuli can depress lactation, but there is much less information in humans. Experimental studies in breastfeeding women have shown that acute physical and mental stress can impair the milk ejection reflex by reducing the release of oxytocin during a feed. If this occurs repeatedly, it could reduce milk production by preventing full emptying of the breast at each feed. Prospective observational studies indicate that both maternal and fetal stress during labor and delivery (e.g., urgent Cesarean sections or long duration of labor in vaginal deliveries) are associated with delayed onset of lactation. The effects of chronic emotional stress on lactation are not known. Mothers who experience high levels of stress during and after childbirth should receive additional lactation guidance during the first week or two postpartum.