Presence of Macroprolactinemia in mothers with insufficient milk syndrome

Each year there are thousands of women who for some unknown reason, can't produce enough milk for their infant. Unfortunately,  we know very little about hormones and breast milk production,  thus we are largely unable to account for this high failure rate in some breastfeeding mothers.   Many of these mothers have done everything right,  and even have elevated levels of the milk hormone, Prolactin,  but are still unable to produce sufficient quantities of milk.

I have a theory that they actually have the wrong kind of Prolactin.

For some years now,  we've known that some women produce three different kinds of prolactin,  two of which are completely INACTIVE.

Active Prolactin is a large hormone that is released by the mothers pituitary when she breastfeeds.   We now know that the pituitary in some women produce high levels of  two non-functional types of Prolactin.  We call these Big-Prolactin,  OR  BIG-BIG Prolactin.   Both the latter forms are 'inactive'.

All of the various forms of prolactin show up in the normal prolactin blood test as normal prolactin,  so these women and their physicians "think" they have plenty of prolactin,   but it may be the wrong inactive form.  We call this condition "Macroprolactinemia".  

Now I'm wondering if many of these moms with high prolactin levels, who produce little or no milk, may have the wrong kind of prolactin,  Big-prolactin, or Big-Big prolactin.  Both of these show up as prolactin in the normal blood test,  but they are not normal and are inactive.

Therefore,  this research is designed to find two kinds of mothers (below) and we are going to test for all the versions of prolactin and see if this theory is correct.

We want a single blood sample from:

1) Breastfeeding mothers with poor milk production, and HIGH prolactin levels.


2) Moms with a diagnosis of PCOS (polycystic ovary syndrome), that have high prolactin levels, and poor milk production. 

It is a simple process,  we want moms who fit the inclusion criteria below to contact us,  be consented,  and then we'll ask you to go to a Quest Laboratory facility to have a single blood draw.  The lab will give you a tube with blood, and you can then send it to my laboratory.  We'll give you a box and return instructions.  It won't cost you anything.

If you fit the Inclusion Criteria below,  and wish to participate in this study,  please contact my Clinical Research Center staff for more information.    806-414-9742

At this time there is no cure for Macroprolactinemia.  If you have this condition,  it will only allow us to tell you “why” you are not able to make milk, and let you adjust your life to live with this condition. 


Warmest Regards

Thomas W. Hale, R.Ph., Ph.D.

Teresa Baker, M.D.


Inclusion Criteria

1     Breastfeeding mother from 18-45 years of age.

2     Mother with infant 37 weeks gestation or older and < 5 months old.

3     Currently unable to produce sufficient milk daily for her infant.

4     Non-smoking, not current tobacco use of any kind.

5     Breastfeeding mothers with high prolactin levels and poor milk production or PCOS and poor milk production.


Exclusion Criteria

1     Mother who has stopped trying to breastfeed or pump milk for her infant.

2     Infant is > 5 months old.

3     Mother who is pregnant.

4     Mother who has received Cabergoline(Dostinex) or  Bromocriptine (Parlodel)

5     Mother who has had breast reduction surgery.