How High Prolactin Levels Can Impact Your Fertility and What To Do About It
If you are currently trying to conceive or have been struggling to get your period for months, even though every pregnancy test you take is negative, it’s important that your doctor evaluate your prolactin levels. Prolactin is a unique hormone that is released solely from what are known as lactotroph cells in the anterior pituitary gland, aka your brain. Prolactin contributes to hundreds of physiological functions, but the two most notable include breast milk production and the development of mammary glands within the breast tissues. Prolactin stimulates the growth of mammary alveoli, which is where milk production is made. Although it is normal for prolactin levels to rise with pregnancy and shortly after postpartum to help initiate milk production, elevated levels of prolactin can interfere with the normal production of other hormones, such as estrogen and progesterone. This can change or even prevent ovulation and can lead to irregular or missed periods. Although some women will experience symptoms like irregular or missing periods, some will present without obvious symptoms. So, what causes high prolactin and what can you do about it?
Normally serum prolactin levels gradually increase during pregnancy and, to a lesser degree, in response to nipple stimulation during breastfeeding, physical exertion and stress. This is important to mention because extreme exercise, as well as chronic stress can absolutely cause an increase in prolactin levels, which in turn, can make it harder to get pregnant. So, if your recent labs have revealed a slightly elevated prolactin level, before jumping to the conclusion that you have a tumor, it’s important that we take a step back and evaluate the more likely causes. The upper normal value for serum prolactin levels by most laboratory companies is approximately 20ng/mL. Now, remember prolactin can also be slight stimulated by foods so if your prolactin levels were only slight elevated (up to 50ng/mL), it should always be repeated on a fasting sample. Sometimes repeating your labs, especially for prolactin, is the first and most important step.
Stress + Prolactin
Stress can come in a variety of different forms including physical but also psychological. Stress is not only known to impact fertility, but it can do so by increasing serum prolactin levels preventing ovulation. Although stress can also increase prolactin in men, women appear to be more sensitive to stress, in terms of prolactin stimulation. This is though to be because of the higher serum estradiol (active estrogen) levels found in the lactotroph cells (remember those cells in the brain that stimulate prolactin). Although stress can impact prolactin levels, most of the time, stress will impact prolactin levels to a lesser degree than other pathological causes. So, if you’re serum prolactin levels are above 20ng/mL but below 40ng/mL, it’s time we evaluate your stress and discuss stress management techniques.
Dopamine + Prolactin
Dopamine acts as a co-regulator of both prolactin but also growth hormone and luteinizing hormone, reducing the amount of prolactin released by the pituitary. Since dopamine inhibits the release of prolactin and LH, in theory, low levels of dopamine may lead to excessive release of prolactin from the pituitary. Some of the dopamine agonist drugs, like cabergoline, have been associated with a reduction of androgen and prolactin levels, especially in women with PCOS. The use of dopamine-promoting herbs, like Melissa citronelle (lemon balm), Cimicifuga racemosa (black cohosh) and Vitex agnus castus (chaste tree berry), have also been considered for lowering androgen and prolactin levels, especially in women with PCOS. Since these botanicals can impact dopamine, it is important to always consult with your doctor before starting any new supplement or medication.
PCOS + Prolactin
If you are experiencing irregular cycles and your doctor “assumes” you likely have PCOS, otherwise known as Polycystic Ovary Syndrome but didn’t run any bloodwork, this should be a red flag. Although PCOS is the most common cause of female infertility, irregular cycles can be caused by a variety of other factors, including hyperprolactinemia. At NMD Wellness of Scottsdale, we believe comprehensive testing is a key factor to address the root cause of infertility. Although prolactin levels are usually normal in women with PCOS (generally less than 25ng/ml), it is important to check for high prolactin levels in order to rule out other possible causes including pituitary tumors, that might be causing PCOS- related symptoms. Again, not everyone has a brain tumor if they have elevated prolactin levels, but your doctor should be doing their due diligence to evaluate all causes so we avoid misdiagnosing a patient.
Drug Induced Hyperprolactinemia
High serum prolactin, otherwise known as hyperprolactinemia, can be caused by a variety of issues, but one that is not talked about enough is medication/drug- induced hyperprolactinemia. In drug-induced hyperprolactinemia, serum prolactin levels are generally between 25 to 100ng/mL. The one exception to this is risperidone, an antipsychotic drug, which has been associated with serum prolactin levels as high as 200ng/mL. Some of the other common medications associated with elevated prolactin include:
-
Antidepressants
-
Clomipramine (more commonly)
-
SSRIs, like fluoxetine, sertraline and paroxetine (less common, but some rare reports)
-
-
Antiemetics
-
Metoclopramide
-
-
Anti-hypertensives
-
Methyldopa
-
Not only can certain medications cause elevated serum prolactin levels, but medication-induced hyperprolactinemia can presents as symptoms of decreased libido and erectile dysfunction in men and non-pregnant milk production (galactorrhea) and missed periods (amenorrhea) in women.
Prolactinomas
Although less common, if you are experiencing prolactin levels greater than 250μg/dl, it is important that we evaluate the presence of a prolactinoma. If prolactin levels are greater than 500μg/dl, this is diagnostic for macroprolactinomas. Prolactinomas are noncancerous tumors of the pituitary gland that can cause the pituitary gland to produce too much prolactin. Although the cause of prolactinomas are largely unknown, in some causes there are genetic factors that appear to play an important role. Especially an inherited disorder known as multiple endocrine neoplasia (MEN) type I appears to increase your risk for prolactinomas. Prolactinomas are rare and occur in about 1-2 per 10,000 people. If a prolactinoma is identified, the treatment is generally surgery and involves removing the tumor through the nasal cavity, which is known as transsphenoidal surgery. Again, this is rare and should only be a consideration if serum prolactin levels are above 250μg/dl.
Estrogen + Prolactin
Estrogen can also increase serum prolactin levels. Although the mechanism is not completely understood, it is thought that estrogen stimulates prolactin secretion when estrogen binds to an estrogen receptor. This binding appears to stimulate the binding of an estrogen response element on the prolactin gene in the lactotroph cell of the pituitary. Researchers believe that although this might explain why hormonal contraceptives could increase prolactin levels, the amount of estrogen in hormone contraceptives does not typically cause hyperprolactinemia.
Hypothyroidism + Prolactin
Did you know that having hypothyroidism (low thyroid function) can predisposes you to hyperprolactinemia. This is again where addressing the root cause really matters. Researchers found that the people with hypothyroidism and elevated serum prolactin, treating the hypothyroidism, corrected the prolactin levels in most patients. However, it is important to recognize that hypothyroidism is a potential cause of an enlarged pituitary gland so evaluating your thyroid and pituitary function is important, especially in those with thyroid disease.
About the Author: Meet Dr. Zen
Alissia Zenhausern- Pfeiffer, NMD, FABNE, (commonly known by her patients as Dr. Zen), is a licensed naturopathic doctor board certified in naturopathic endocrinology and the founder of NMD Wellness of Scottsdale, a premier naturopathic medical practice that focuses on helping women to take a proactive approach to their hormone and fertility health. Dr. Zen has been featured as a lead expert in Forbes, Shape Magazine, and Instyle and is deeply passionate about bridging the gap between traditional and natural medicine in the world of fertility. She works with a variety of hormone related issues including PCOS, endometriosis and unexplained infertility. Her goal is to help more women get back into the driver’s seat of their own health to make lasting transformational changes to their health to bring more cute and adorable babies into this world. Read More About Dr. Zen...
