In the delicate hormonal balance that regulates fertility, there are well-known hormones, such as estrogen and progesterone, and others that often go unnoticed, like prolactin.
Although it is mainly associated with breastfeeding, this hormone can also directly affect reproductive ability.
What is prolactin?
Prolactin is a hormone produced by the pituitary gland. Its main function is related to the production of breast milk after childbirth. However, when trying to conceive, prolactin levels need to stay within an appropriate range, because too much prolactin can interfere with the normal functioning of the reproductive system.
A natural “brake” on fertility
During breastfeeding, prolactin levels naturally rise to stimulate milk production. This increase also acts as a “brake” on ovulation, reducing the chance of a new pregnancy during this period. This explains why many women do not menstruate or ovulate in the first months of breastfeeding. The problem occurs when this same mechanism is active outside the breastfeeding period, in women who want to conceive, because too much prolactin can become an obstacle to achieving pregnancy.
How does excess prolactin affect fertility?
Excess prolactin (hyperprolactinemia) occurs when prolactin levels exceed what is considered normal (usually above 20–30 ng/ml, depending on the laboratory). This hormonal imbalance can make conception more difficult in several ways:
1. Ovulation problems
High prolactin levels can cause :
- Absence of ovulation (anovulation).
- Irregular or unpredictable menstrual cycles.
In both cases, it can be difficult to conceive naturally or to plan assisted reproductive treatments.
2. Luteal phase problems
In some cases, prolactin does not prevent ovulation but interferes with progesterone production, the hormone responsible for preparing the endometrium for embryo implantation. When the luteal phase is too short or the endometrium is not optimal, implantation can be affected, even if fertilization occurs.
What are the main causes of an excess of prolactin?
Hyperprolactinemia is not always related to a serious condition. In many cases, it can be caused by temporary factors, such as stress, lack of rest, or certain lifestyle habits. It may also be associated with hormonal disorders, such as hypothyroidism or polycystic ovary syndrome, or with the use of some medications.
Understanding prolactin in the hormonal context
Prolactin is just one of many hormonal factors that influence fertility. A high value is not a definitive barrier, but a signal that the hormonal balance needs to be evaluated before continuing to try for a pregnancy. In most cases, hyperprolactinemia can be treated, and once corrected, the chances of pregnancy improve significantly. That is why it is important to evaluate each case individually, identify the cause of the imbalance, and determine the best approach according to each patient’s clinical situation.
