The Relationship Between Estrogen and Prolactin 
by DrJim

 

For a woman wanting to induce lactation, understanding the relationship between Prolactin and Estrogen is perhaps the most important hormonal thing to know. Inducing lactation is essentially inducing the post partum hormonal state that begins shortly after delivery when her breasts want to produce milk and the woman worries about producing too much rather than too little. The post partum state is a condition where her hormones are balanced differently than in the normal non-pregnant state. This balance is low Estrogen and high Prolactin. Some might say; isn’t low Estrogen a bad thing, she will loose her femininity and sexual interest? Not so, granted, there are changes that occur from the low Estrogen including slower vaginal arousal. The high Prolactin however, causes other balancing changes, a greater sensitivity of the breasts to arousal and it brings out the feminine behavior and feelings termed “nesting”. The nesting behavior is a very feminine and alluring thing that most men find quite irritable in a woman. Some husbands might interpret the low Estrogen- slower clitoral arousing condition as a loss of sexual interest and feel as though their wife has lost interest in them. Her preoccupation with nesting with and nursing the infant may make him feel excluded. This does not need to be so. Her hormonal state has caused her to have more interest and sexual arousal through her breasts to make up for the decrease vaginally. This is something for him to explore with her.

When a woman induces lactation at times other than post-partum, she is actually inducing the post-partum hormonal state. This underlying hormonal state is the true condition of lactation. The breasts will surely change, begin lactating and reflect this underlying hormonal state if it occurs. So the focus should be on how to achieve this hormonal state rather than on how to make the breasts lactate when they don’t want to. This is why understanding the relationship between Prolactin and Estrogen is important. I also think women find the emotions and feelings that make up the “nesting behavior” to be the thing that they enjoy the most, rather than simply having milk in their breasts.  

Functionally and very simply, the hormones Estrogen and Prolactin oppose each other. When one is high it suppresses the other. These two hormones are like a Seesaw, one goes up, the other goes down. Not only this, the Seesaw prefers to have one or the other end down rather than to be balanced in the middle with both hormones equal. In the normal non-pregnant state the Seesaw is balanced with high Estrogen and low Prolactin. To get this Seesaw to tip the opposite way requires much nipple stimulation. Once it is tipped the other way it usually requires less effort to keep it tipped toward Prolactin because the breasts increase their sensitivity and response to stimulation and put out much more Prolactin with stimulation. The greatest sign that the Seesaw is tipped fully toward Prolactin is when the woman stops menstruating. When this occurs it means the ovaries are quiet and not putting out Estrogen in the normal monthly cyclic pattern.  

The post-partum state begins when the woman delivers the baby and placenta. The placenta is the source of all the high hormone levels during pregnancy. The ovaries are quiet because the FSH (follicle stimulating hormone) that turns them on has been absent. As she enters this low Estrogen state the sensitivity for Prolactin release is turned on. Her Seesaw is tipped fully toward Prolactin. If she breastfeeds frequently enough, the FSH signal will be suppressed, Estrogen will stay low, she will not menstruate and her breasts will produce copious amounts of milk. This condition can last for as little as a month or so to a year or more. When the breastfeeding frequency and nipple stimulation decreases, typically when the infant is being weaned, her menstrual cycle will return and she becomes fertile again. This indicates that FSH suppression is not complete because the interval between breastfeeding events has increased to the point that the FSH signal is escaping and intermittently stimulating the ovaries. When the FSH signal becomes strong and regular enough, her Estrogen level will rise enough to cause her breasts to dry up. The Seesaw has tipped back toward high Estrogen.  

Many women are able to continue to lactate partially and be fertile and have their menstrual cycle at the same time. This is a condition where the Seesaw is balanced in the middle. It can be a very long lasting state actually, but usually requires regular nipple stimulation to maintain it. When inducing lactation, I believe most women can find this balance only by first getting the Seesaw tipped toward the high Prolactin side for some minimal time then letting it balance back toward the middle. 

When beginning to induce lactation most women find that even though they stimulate the nipples a lot there is no milk, even if the breasts have the alveoli and are ready to produce it. This is because of their high Estrogen state. Their hormonal condition has to be tipped toward Prolactin through nipple stimulation for a while before any actual milk will be produced. Again, it is important to remember that the breasts in their size, shape, development and readiness simply reflect the underlying hormonal balance or state of the woman. 

During pregnancy a woman’s breasts are hormonally stimulated to grow lots of alveoli and be ready for lactation when the post partum state comes. This hormonal induction is not necessary for women to go through when they are younger and their breasts are in a fairly ready state. They can usually have good success by inducing through nipple stimulation alone. When women are nearer menopause their low hormonal state may cause their breasts to loose most of their alveoli. For them they may have better success by mimicking the pregnancy to post partum sequence, which is hormonal stimulation followed by nipple stimulation. I believe there are two most common causes of failure to produce any significant amount of milk after a reasonable length of time spent stimulating the nipples, they are; 1. Persistent high Estrogen state keeping the Seesaw tipped away from Prolactin (most common in younger women). 2. Not very many alveoli present to respond to the stimulation (most common in older women) 

Now for those who want to know the actual hormonal pathways involved in this Seesaw. Notice how Estrogen reinforces itself and inhibits Prolactin while Prolactin reinforces itself and inhibits Estrogen; Nipple stimulation sends a signal to the Pituitary to cause it to release Prolactin. Over time Prolactin causes the breasts to change and develop leading to lactation. The nipples and areola respond to this stimulation by enlarging and becoming more prominent and developing more nerve endings. The nipples become more sensitive to suckling so that more Prolactin is released with the activity. The signal to the Pituitary satisfies it in place of Estrogen so that it turns off its FSH (Follicle stimulating hormone) signal for a short time (with repeated stimulation this signal can stay off). This inhibits the ovaries in their production of Estrogen. Estrogen released by the ovaries is associated with the development of follicles that ovulate and release an egg at mid month. This process is inhibited when FSH is inhibited. The other side; Estrogen feeds back to the Pituitary and elevates a hormone called PIF (Prolactin inhibitory factor). This hormone causes the Pituitary to be less sensitive to nipple stimulation and the release of Prolactin

Domeperidome increases the sensitivity of the Pituitary to nipple stimulation so that more Prolactin is released. There are other ways to increase Prolactin release, primarily through efforts to lower Estrogen levels. Lowering Estrogen as well as raising Prolactin is what a woman is attempting to do when inducing lactation through nipple stimulation. This is what the Seesaw is about. Progesterone is another hormone, which functionally inhibits Estrogen and can help tip the Seesaw over into the high Prolactin state. Progesterone also causes more alveoli to develop in the breasts. Progesterone supplementation, if considered, can help bring on lactation in young and older women.

 

DrJim

 

 

   

 

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