Overactive let-down

Is overactive letdown really a thing, or is there something going on with baby's anatomy contributing to this issue? I wrote this article in response to an online comment I saw online by a woman who called herself a lactation doula... There is no such thing as a lactation doula which was my first red flag: read more about "who's who in lactation and perinatal care" in my blog post on the subject.

Breastfeeding is a complex endeavor the success of which is based on many factors. The purpose of this article is to explain the basis of overactive letdown and outline some solutions. The solutions I mention are not a replacement for good lactation support and a customized plan of care, but they are great tips to start with if you're experiencing what we call overactive let down.

“Let-down or the milk ejection reflex (MER) is driven by oxytocin* levels in the mother and is received by oxytocin receptors in her breasts; NOT by the anatomy of the baby.”

One of the first things to understand is that endocrinologic (hormonal) factors are at play here. First it is essential to know that let-down or the milk ejection reflex (MER) is driven by oxytocin* levels in the mother and is received by oxytocin receptors in her breasts; NOT by the anatomy of the baby. Baby's anatomy can and does affect the feedback loop that releases oxytocin. Oxytocin is relased in a positive feedback loop.  For breastfeeding this feedback loop is driven by prolactin and requires milk removal via nursing, pumping, or hand expression. Prolactin drives milk production and the release of oxytocin. When a baby has factors that lead to ineffective milk withdrawl; this can dampen milk production. While the mother's anatomy is what determines the ability of a mom to "let-down" her milk, a baby's anatomy can contribute to nipple pain which would inhibit the letdown reflex (the OPPOSITE of overactive letdown). So why did someone think that overactive let down is not real and is actually not an phenomenon caused by mom?

Since we know MER is based primarily on maternal anatomy and physiology we can now make a mental leap and realize that an "overactive" or "forceful" MER will occur even if mom were pumping or hand expressing. Now, let's think about what will happen when we bring baby's anatomy into the picture. Let's start by thinking about ourselves drinking from a water fountain. The first fountain is high pressure, high flow, the second is your typical water fountain, maybe even one of those annoyingly low flow, sluggish fountains. Which fountain would you find easiest to drink from? Which of the three would you have the most trouble drinking from.

Now take this fountain analogy and imagine a baby with normal and functional mouth anatomy. This baby would have the same issues as an adult. They would have some sputtering and maybe leak some of the water from the "overactive" fountain and would do great with the usual kind of fountain, and then again may struggle, or perhaps not prefer the lower flow fountain. Of course we are talking about breasts here, but hopefully you're starting to put together the picture.

Finally let's think about a baby with an oral dysfunction (tongue-tie, hypotonia, cleft palette) and how they would have increased difficulty navigating the "overactive" milk flow. So while the overactive MER is based on the attributes of the mother, the baby's anatomy determines how much s/he is affected.

So how does MER, especially overactive MER affect the breastfeeding parent?

What external factors can affect MER? Medications given during birth and maternal physiology altered by surgery, disease, or injury can affect MER. Some external things like seeing, smelling, or hearing your baby can induce or facilitate the response. Unfamiliar or uncomfortable environments (read feeding or pumping in a restroom or public place) can inhibit this chain reaction.

Leaking is common if MER is induced before a baby is put to breast. Overactive MER can cause above average leaking, especially close to when a feeding is due, or even when hearing any baby cry. Leaking from the breasts can affect women in social situations, in business situations, and even during intimacy. This can range from being inconvenient to distressing.

Overactive MER may make it difficult for a baby to feed causing the need for lactation support, and potentially with a mangement plan that adds to the parent's workload.

Overactive MER can exist both with and without overproduction, but the pathways for both production and MER are both related. D-MER, short for dysphoric Milk-Ejection Reflex is another phenomenon that can occur, which is where the nursing parent experiences upsetting and negative feelings eg dysphoria, when MER occurs. These feelings are transient but have a lasting effect on the mother's experience with breastfeeding. The dysphoria is thought to occur because oxytocin inhibits dopamine and in some women may lead to an abrupt drop in dopamine levels. If you experience D-MER, contact a local IBCLC for help on how to mitigate your symptoms. You can also find mental health resources through Postpartum Support International.

*Oxytocin is a hormone that is produced in the hypothalamus and then released by the posterior pituitary gland. Oxytocin has many complex roles, but commonly it is known as the happiness hormone. It is critical for bonding and "maternal behaviors".