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If you’re on your fertility journey, you’ve likely heard of prolactin. It’s often called the “milk hormone,” but it does so much more than just help with breastfeeding.
This hormone, produced by your pituitary gland, is a major player in your reproductive health.
Studies show that high prolactin levels affect 9 -17% of women with reproductive disorders. This makes it one of the leading causes of infertility.
We’re here to give you the low-down on this question: how does prolactin affect fertility? We’ll also cover what causes hormonal imbalances and how you can normalize prolactin levels to support a healthy pregnancy.
Key Takeaways
- Prolactin is vital for both female fertility and male reproductive function.
- High prolactin levels (hyperprolactinemia) can block your brain from sending the signal to ovulate.
- It’s a common cause of irregular periods and unexplained infertility.
- Men need balanced prolactin levels for healthy sperm production and sexual desire.
- Most cases are easily treated with medication or simple lifestyle changes.
What is Prolactin?
Prolactin is a hormone produced by the pituitary gland. We know it best as the hormone responsible for breast milk production and growing breast tissue. But it also helps regulate your metabolism, immune system, and hormonal balance.
The brain uses a “brake and gas” system to control this hormone. Dopamine is the natural brake. It inhibits prolactin release to keep your levels low. On the other hand, things like thyrotopic-releasing hormone (TRH) can act like the gas pedal. This can cause your prolactin levels to spike.
It’s important to know the difference between a “normal” rise and a problem. Your levels naturally go up when:
- You sleep
- You’re under high stress levels
- After excessive exercise
These are physiological changes. Prolactin levels rise within expected ranges and return to baseline.
What is a pathological change? It’s when levels stay high due to things like a pituitary adenoma (a non-cancerous tumor) or an underactive thyroid.
What Are Normal Prolactin Levels?
Here’s what normal prolactin levels look like:
Group | Normal range (ng/mL) |
Non-pregnant women | 2-30 |
Pregnant women | 200-500 |
Men | 2-18 |
How Does Prolactin Work for Women?
In non-pregnant females, prolactin helps your eggs mature and prepares them for fertilization. It supports the formation and function of the corpus luteum after ovulation. This improves the chances of embryo implantation.
Prolactin also helps prepare the uterine lining for pregnancy. It keeps the embryo and uterus in sync. Interestingly, it even supports sperm survival with low motility.
Prolactin levels naturally change during the menstrual cycle. This shows their involvement at every stage of reproduction.
For non-pregnant women, normal prolactin levels are 2 to 30 ng/mL
During pregnancy, estrogen causes an increase in prolactin-producing cells. However, high levels of progesterone and estrogen actually stop milk production from starting until after the baby is born.
Once those hormones drop after birth, lactation begins.
For pregnant women, normal prolactin levels are 200 to 500 ng/mL.
How Does Prolactin Work for Men?
Men have prolactin receptors in their testes, specifically on Leydig, Sertoli, and germ cells.
Prolactin helps regulate the receptors for FSH and LH. These are the main triggers for sperm production.
Now, men don’t produce milk. But they still need this hormone to maintain reproductive function and sexual desire.
Normal prolactin levels for men are 2 to 18 ng/mL.
How Does Prolactin Affect Fertility?
The answer to this question all comes down to a communication breakdown in the brain involving the hypothalamic-pituitary-ovarian (HPO) axis.
When you have elevated prolactin levels, it interferes with gonadotropin-releasing hormone (GnRH). GnRH is the master switch in your hypothalamus. If excess prolactin slows down the pulses of GnRH, your pituitary gland won’t release enough luteinizing hormone (LH) or follicle-stimulating hormone (FSH).
Without enough FSH and LH, your ovaries don’t get the signal to grow a follicle. This results in:
What Causes These Abnormal Levels?
Finding the underlying cause is the first step to fixing the problem.
1. Physiological factors
Pregnancy and breastfeeding are the most common. Other causes include:
- Sleep
- Stress levels
- Excessive exercise
- Nipple stimulation
2. Pathological conditions
- Pituitary adenomas: Small tumors (prolactinomas) on the gland
- Hypothyroidism: When you have an underactive thyroid, your body produces more TRH. This raises prolactin levels.
- Chronic renal failure: Your kidneys aren’t working as they should
3. Pharmacological factors
Many medications can raise prolactin levels as a side effect. These medications include:
- Antidepressants
- Blood pressure drugs
- Antipsychotics
What Happens to Women When Prolactin Gets Too High (Hyperprolactinemia)?
High prolactin and fertility issues go hand-in-hand.
In many cases, a woman might not even know her levels are high until she struggles to get pregnant.
Common symptoms in women
- Irregular menstrual periods: Cycles that are too long or too short.
- Amenorrhea: Skipped periods for months.
- Galactorrhea: Producing breast milk when you aren’t pregnant.
- Decreased libido: A drop in your sexual desire.
- Decreased bone mass: Over time, high prolactin levels can mimic menopause symptoms and lead to weaker bones.
If you’re dealing with unexplained infertility, prolactin levels check should be one of the first things your doctor orders. It can further reduce fertility in women who already have tubal factor infertility.
What Happens to Women When Prolactin Gets Too High (Hyperprolactinemia)?
High prolactin and fertility issues go hand-in-hand.
In many cases, a woman might not even know her levels are high until she struggles to get pregnant.
Common symptoms in women
- Irregular menstrual periods: Cycles that are too long or too short.
- Amenorrhea: Skipped periods for months.
- Galactorrhea: Producing breast milk when you aren’t pregnant.
- Decreased libido: A drop in your sexual desire.
- Decreased bone mass: Over time, high prolactin levels can mimic menopause symptoms and lead to weaker bones.
If you’re dealing with unexplained infertility, prolactin levels check should be one of the first things your doctor orders. It can further reduce fertility in women who already have tubal factor infertility.
What Happens to Women When Prolactin Gets Too Low (Hypoprolactinemia)?
Low prolactin and fertility are also a concern. Low prolactin levels are often a sign of pituitary gland damage, autoimmune conditions, or even certain medications.
This is linked to:
- Metabolic dysfunction: Such as Type 2 diabetes, fatty liver, and dyslipidemia.
- Sexual dysfunction: Issues with decreased libido and arousal.
- Increased cardiovascular risk: Higher risk of heart-related issues.
Isolated low prolactin is rare, but it’s a sign that your overall hormonal balance might be off.
What Happens to Men When Prolactin Levels Get Too High?
Men don’t often realize that prolactin hormone levels affect them, too.
Prolactin, LH, testosterone, and estradiol follow timed feedback loops to keep everything balanced.
Studies show that prolactin levels rise in the evening. This rise is actually linked to a nighttime increase in testosterone.
The symptoms of hyperprolactinemia in men show up as:
Erectile dysfunction and decreased libido
Lower sperm quality and concentration
Gynecomastia: Enlarged breast tissue
Decreased bone mass: Risk of osteopenia
Diminished energy: Reduced muscle mass and fatigue
Animal studies insight
Animal studies (like those on adult male mice) show that chronically high levels of prolactin can actually change reproductive behavior.
It makes the body think it’s under stress, which can reduce sperm quality and fertility.
In fasting male rats, these hormonal changes were even more severe. They significantly reduced sperm count.
But there’s good news! Studies show that treating the underlying hyperprolactinemia can reverse the effects. This means improved fertility outcomes.
How Do You Maintain and Restore Normal Prolactin Levels?
The great thing about prolactin and fertility is that once you identify the problem, it’s usually very treatable.
Natural ways
- Manage stress: High stress levels trigger prolactin. Try relaxation, mindfulness, or light yoga to keep levels normal.
- Dopamine-friendly nutrition: Support dopamine function through a balanced diet rich in tyrosine (found in lean protein).
- Sleep hygiene: Stick to a consistent schedule to respect the circadian rhythms of prolactin release.
- Moderate exercise: Intense workouts can cause a temporary prolactin increase. Stick to moderate activity for better hormonal balance.
- Lifestyle changes: Maintain a healthy weight and limit stimulants to support overall equilibrium.
- Treat underlying causes: Hypothyroidism should be addressed to remove any increase in prolactin levels due to TRH.
Medical approaches
- Dopamine agonists: These are the gold standard for fertility treatments. Drugs like Bromocriptine or Cabergoline act like dopamine to reduce prolactin release.
- Thyroid support: If the issue is an underactive thyroid, thyroid medications can help balance TRH and lower prolactin naturally.
- Addressing tumors: Medication usually shrinks pituitary adenomas. Surgery or radiation therapy is only used for very large tumors.
Summary
Prolactin and fertility are connected in a delicate dance. This hormone is essential for preparing the body for a healthy pregnancy, supporting the luteal phase, and ensuring healthy sperm production.
- Monitor your cycle: Irregular menstrual cycles are the #1 sign to check your prolactin levels.
- Check your thyroid: An underactive thyroid is a hidden cause of elevated prolactin.
- Reduce stress: Manage your stress levels to lower the “gas pedal” for prolactin.
- Treat the root: Identifying the underlying cause — whether it’s a tumor or medication — is the only way to restore normal prolactin levels.
By understanding the question, “how does prolactin affect fertility,” you take the power back. This is a common and reversible hurdle on your path to becoming a parent.
Conclusion
Prolactin and its effects on fertility might seem complicated. But the bottom line is simple: balance is everything.
From the pituitary gland to the ovaries and testes, this hormone is a vital messenger. While high levels of prolactin can feel like a major roadblock, they are often just a temporary “pause” button.
With early detection, lifestyle optimization, and the right fertility treatments, you can normalize prolactin levels and get your journey back on track for a healthy pregnancy.
FAQs
Yes, but it can be much harder.
Elevated prolactin levels often stops ovulation. Once you restore normal prolactin levels with medication or lifestyle changes, ovulation usually returns. This allows you to conceive naturally or through IVF.
Indirectly, yes. High levels of prolactin disrupt the follicular phase, which can cause eggs not to mature correctly or the body to fail to release them. This leads to irregular menstrual cycles.
No, you are not permanently infertile. Hyperprolactinemia is a reversible cause of infertility. Once you address the cause behind high prolactin levels, your reproductive function typically returns to normal.
Most fertility treatments require you to regulate prolactin levels before starting.
Abnormally elevated prolactin levels can lower the success rate of IVF treatment by affecting how your ovaries respond to stimulation.
It doesn’t hurt the ovaries directly. Instead, it stops the brain from sending the “start” signal (GnRH).
This prevents the ovaries from receiving the FSH and LH needed to grow and release an egg.
There is no direct scientific evidence that elevated prolactin levels lower your egg count (AMH).
However, it makes the eggs you do have harder to release because it disrupts the menstrual cycle.
The fastest route is to find the underlying cause.
If it’s a pituitary prolactinoma or underactive thyroid, starting the correct medication can often restore normal prolactin levels and ovulation within a few weeks.
Some small studies suggest B6 can help reduce prolactin levels over several weeks. But it’s rarely enough to treat pathological hyperprolactinemia alone.
Always consult a doctor before using any supplements for fertility.
For most women, normal prolactin levels are between 2 and 30 ng/mL.
It’s best to have normal levels. Both elevated prolactin levels and low prolactin levels create fertility issues that can disrupt your hormonal balance and metabolic health.
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