Let-down Reflex - The Role of Hormones and Contributing Factors

Introduction

The let-down reflex is a natural phenomenon that causes easy flowing or ejection of breastmilk. This reflex is generally triggered by the suckling of the baby and is autoregulated by lactating hormones, namely, prolactin and oxytocin. An effective let-down reflex should be established and sustained to ensure an adequate supply of milk. Satisfying deep suckling from the baby, as it continues to remain at the mother’s breasts, indicates a well-working let-down reflex. This article explores the role of hormones and their influence on the let-down reflex.

What Is Meant by the Let-down Reflex?

The let-down reflex is a natural sign indicating that the milk formed in the breasts of lactating mothers is ready to flow through the nipples. This physiological reflex makes the breastfeeding process easier. Some of the prominent signs of the Let-down reflex are as follows -

• Ticklish or tingling sensation in the breasts.

• The pressure experienced on the breasts.

• Lactating mothers feel fullness in their breasts.

• They also feel thirsty.

• Leaking of milk from another breast while the baby is suckling in one breast as the let-down occurs on both sides of the breast at the same time.

• In some cases, the dripping of milk occurs from the breasts when the baby is not even sucking.

• A noticeable change in the suckling pattern of the baby, where shallow quick suckling changes to a deep rhythmic suckling, is a confirmatory sign that the milk has started to flow due to the occurrence of a good let-down reflex.

What Triggers the Let-down Reflex?

The let-down reflex, also called the milk ejection reflex, is an autoregulated natural phenomenon that is initiated in breastfeeding mothers when their babies start to breastfeed. This reflex helps in easy breastfeeding episodes when triggered promptly. Various factors cause the stimulation of the let-down reflex as follows -

• When breastfeeding, mothers hear the sounds from their babies and their hungry cues.

• Seeing and smelling their babies initiates the let-down reflex.

• Even when they lovingly think of their infants.

• The let-down reflex is also triggered when the nipple area of the breasts is touched and by a gentle massage on the breasts.

• Closeness to the baby, particularly skin-to-skin contact stimulates the let-down reflex. Thai practice is commonly encouraged in the initial hours of breastfeeding to establish feeding between newborns and their mothers.

What Is the Role of Hormones in the Let-down Reflex?

Hormones are key factors in establishing effective milk production and breastfeeding. The two predominant hormones that influence breastfeeding are prolactin and oxytocin. Ovarian hormones such as estrogen and progesterone also contribute indirectly to the lactation process. Numerous sensory nerves are present in and around the nipples, which are stimulated when the baby latches to the nipples for breastfeeding. The sensory impulses are transmitted from the nipples to the brain when the baby starts suckling. The pituitary, the master gland for hormones, secretes prolactin (the anterior lobe of the pituitary gland) and oxytocin (the posterior lobe).

Role of Oxytocin

The hormone oxytocin is responsible for milk ejection as it causes the contraction of the milk-storing cells and pushes the formed milk through the nipples. Oxytocin contributes to the let-down reflex in the following ways -

• Oxytocin contracts the myoepithelial cells (similar to muscle cells) that are present around the alveoli (milk-containing cells) in the nipples.

• This makes the milk collected and stored in the alveoli flow through the milk ducts and fill them. Fine streams of milk are ejected.

• Oxytocin also widens the milk ducts, thereby making the milk flow easier and more adequate.

• Due to its effects, the let-down reflex is also called the oxytocin reflex or milk ejection reflex.

• Oxytocin is more quickly produced and is faster in action than prolactin.

• This causes the already-formed milk in the breasts to flow for the current breastfeeding and helps in the easy and quicker availability of milk to the baby.

• The action of oxytocin starts when the breastfeeding mother expects the feed and when the baby initiates suckling.

• The sensations and feelings of the lactating mothers condition this reflex and establish its occurrence by enhancing oxytocin activity.

• Seeing their infants, touching them, hearing their babies’ hungry cues, smelling, and also affectionately thinking about them are some of the positive sensations that favor the let-down reflex.

• Severe pain or discomfort, illness, emotional upset, stress or anxiety, fatigue, and over-self-consciousness to express milk, particularly in public, inhibit the oxytocin reflex and interrupt the milk flow during breastfeeding episodes.

• To achieve an appropriate oxytocin reflex during the initial hours after delivery, the mother and the neonate should not be separated for a longer duration and must be kept together to establish skin-to-skin contact.

Role of Prolactin

The hormone prolactin is essential for milk production (lactogenesis) and for its effective secretion by the milk-forming cells (alveoli). The prolactin levels increase in the blood when the baby suckles, which results in subsequent milk production by the alveoli. Prolactin plays a major role in establishing lactation during the initial few weeks. Increased suckling by the baby stimulates the nipples, leading to elevated prolactin levels and increased production of milk.

What Are the Strategies That Encourage the Let-down Reflex?

Though the let-down reflex is conditioned (an automatic response that occurs on stimulus) and is well regulated by hormones, certain sensory and emotional factors such as stress, tiredness, and pain result in difficulty during breastfeeding and delayed initiation of the let-down reflex. Receiving reliable support helps comfort lactating mothers and resume milk flow for the babies to continue to be breastfed again. Here are some recommendations that help to establish a good let-down reflex.

• Ensuring proper positioning of the baby with correct attachment to the breasts and proper latching to the nipples. A well-attached infant would facilitate better milk removal from the breasts.

• Breastfeeding in a familiar, clean, and comfortable environment favors an easy let-down reflex.

• Relaxing methods such as listening to calm music, taking a warm shower, washing the breast with warm water, practicing slow, deep breaths, and gentle neck and shoulder massage reduce anxiety and facilitate let-down reflex and effortless breastfeeding.

• Gentle hand expressing or massaging the breasts before initiating the breastfeeding session helps in effective let-down reflex.

• Looking and thinking affectionately about the baby ensures a positive response.

• Keeping breastfeeding mothers adequately hydrated (having a glass of water before breastfeeding) reduces fatigue in them and removes inhibition on the let-down reflex.

• Seeking professional support from lactation educational resources such as lactation counselors and consultants would help in overcoming the setbacks and achieving a good let-down reflex.

Conclusion

In breastfeeding mothers, lactating hormones such as prolactin and oxytocin directly influence the breastfeeding process and contribute to the establishment of a good let-down reflex. Emotional stress and anxiety have negative effects on it, whereas affectionate thinking and a positive sensory touch of the babies increase the reflex and easy breastfeeding.