As I was going through a stack of photographs that I found, I came across this one of Nathanael and I when he was just a couple months old. I was shocked at how skinny he was! I was determined to breastfeed him, and it wasn't going very well. When I had Rebecca, 13 years ago, my milk supply was great! One year later, when Zack was born, I developed graves disease. (a very underactive thyroid) I didn't know then that my underactive thyroid was the reason I wasn't successful with breastfeeding Zack or my next child, Elijah, who was born one year later. Eight years passed and I had Nathanael. Again, my milk supply was very, very low. But I was determined. I nursed day and night, took herbs and prescription pills that were supposedly helpful in building milk supply, but nothing helped. The prescription pills made me extremely sleepy. Needless to say after about three months of trying to run my household half asleep from the recliner, I gave up and began to supplement with bottles. Nate gained weight! But finding a formula that agreed with him was tedious. So, for the most part, he was fed goats milk. As soon as he was on a good diet of soft foods, we cut the bottles out altogether and put him on a good liquid vitamin. By then, I was pregnant with James and thinking, how in the world could I go through all that again! I prayed and pondered and researched the internet on possible reasons why I didn't have a great milk supply. The light began to dawn and I asked my good friend and favorite doctor, Dr. Punger, if it was possible if my thyroid was interfering with breastfeeding. She said she thought it just might. So, I went home and looked up articles on the internet to see if there was a connection. Turns out, I was right! The thyroid gland determines the function of the mammary glands which determines the milk supply. Underactive thyroid = underactive mammary gland = low milk supply! I saw a endocrinologist in West Palm, and before James was born, my thyroid was stable again. Miracle of all miracles, I had milk! Not a big deal if you never suffered from low supply, but it was huge to me! After James was born, he developed into a thriving, happy, fat baby! I was able to nurse him until I had to go to work, after 5 or 6 months. I pumped as long as I could, but my supply dwindled with infrequent nursing. I don't know if anyone out there who reads this has low supply, but if you do and nothing else is working, check your thyroid! (It's very common for women's thyroids to be out of balance anyway, after a pregnancy.) Happy nursing ~ happy bonding!
PS. Since I'm not a doctor or scientist, I'm going to add this article that I found on the web that explains the connecting between low thyroid and low milk supply much better than I can. I found it at this website: www.thyroid.about.com/library/derry/bl12.htm
Post partum thyroid dysfunction is common especially in women with Hashimoto's thyroid inflammation. This can express itself as mild depressions through to full paranoid delusions and psychotic behavior. With the help of anti-depressants and thyroid most people can be brought out of this quite quickly. One of my most serious cases of mine involved frightening thoughts by the mother about harming her baby. She buried all of her kitchen utensils in the back yard. Fortunately she responded rapidly within a week to thyroid hormone and anti-depressants. From there she went on to do well.
During the pregnancy the demands for thyroid hormone and iodine are more than normal. The placenta also puts out a hormone to make the thyroid work more. So when the stress of the pregnancy is removed the thyroid may end up partially burned out. So just when the mother needs to cope well (needs thyroid hormone) she is left with a worn out thyroid.
Adequate thyroid hormone is essential for initiating breast feeding and this is where that problem comes from. All mammals need thyroid to initiate breast feeding and it is most extreme in the cat. During the immediate post partum period the cat totally empties its thyroid in order to start breast feeding. (1) As well thyroid hormone initiates and controls the last enzymatic process in the breast to make milk.
The thyroid hormone and thyroid gland together with iodine are the most important factors by far for completion of a normal pregnancy and normal baby. Iodine is put into the mother's milk by the lactating breast to levels that are 30 times the levels in the mother's blood. Iodine still has important functions in the child's brain development after birth. Most likely the iodine in the mother's milk is the same function as the iodine in pregnancy which is ensure that the natural death of cells occurs (apoptois). The death of many cells in the brain and elsewhere during development is an important function. Newer evolutionary parts of the brain replace older ones. Because there is limited space in the skull some cells have to die off to make room for the more evolutionary modern cells. It has been estimated that about 80 percent of the brain tissue is replaced during development in this manner.
There is an increased need for thyroid hormone and iodine during pregnancy. Thus each pregnancy is a load on the thyroid function which not every women's thyroid gland carries out adequately. As thyroid is important for adolescence, normal menstruation, pregnancies and menopause it is not surprising the females have a much higher incidence of thyroid dysfunction.
So I feel poor milk production in women with a history of thyroid dysfunction is likely related to low blood levels of thyroid hormone. As breast feeding is so important to the child and mother it seems important to check this out at the time.
It is likely that if thyroid hormone is given to a mother with breast feeding problems the problems would disappear quickly within a week.
Hope this helps answer your question.