What is the significance of a mildly elevated prolactin level in a 38-year-old female with shortened menstrual cycles, in the absence of abdominal pain and genitourinary (genito-urinary) symptoms?

From the Guidelines

A prolactin level of 1.74 ng/mL in a 38-year-old woman with shorter menstrual cycles is actually within the normal range and does not require treatment. Normal prolactin levels for non-pregnant women typically range from 2-29 ng/mL, though reference ranges may vary slightly between laboratories [ 1 ]. The slightly low-normal prolactin level is not likely causing your shorter menstrual cycles. Instead, these shorter cycles may indicate changes in ovulation patterns that are common as women approach their 40s.

Possible Causes of Shorter Menstrual Cycles

• Changes in ovulation patterns due to age-related decline in ovarian reserve [ 1 ]
• Functional hypothalamic amenorrhoea (FHA), which is caused by chronic anovulation and can be triggered by stress, weight loss, or psychological disorders [ 1 ]
• Other reproductive endocrine disorders, such as polycystic ovary syndrome (PCOS) or hyperprolactinemia, although the prolactin level in this case is within normal range [ 1 ]

Recommendations

• No immediate intervention is necessary since the prolactin level is within normal range and there are no symptoms of abdominal pain or genitourinary symptoms [ 1 ]
• Regular gynecological check-ups are still recommended to monitor any changes in menstrual patterns over time [ 1 ]
• If menstrual cycles become increasingly irregular or other symptoms like heavy bleeding or severe cramping develop, follow-up with a healthcare provider is necessary [ 1 ]

From the Research

Prolactin Level and Menstrual Cycle

• A prolactin level of 1.74 in a 38-year-old woman with shorter menstrual cycles may be indicative of hyperprolactinemia, which can be associated with polycystic ovary syndrome (PCOS) 2.
• However, the study suggests that the association between hyperprolactinemia and PCOS may be fortuitous, and hyperprolactinemia in women with PCOS should lead to etiological investigations, including eliminating macroprolactinemia 2.

Diagnosis and Treatment of PCOS

• The diagnosis of PCOS is primarily clinical, based on the presence of at least two of the three Rotterdam criteria: oligoanovulation, hyperandrogenism, and polycystic ovaries on ultrasonography 3.
• Menstrual irregularities due to anovulation or severe oligoovulation are a key feature of PCOS, and first-line intervention should entail dietary and lifestyle modifications for overweight or obese PCOS women 4.
• Combination low-dose hormonal contraception are the most effective and first-line choice for regulating menstrual cycles in women with PCOS who are not seeking fertility 4.

Hormone Tests for PCOS

• Total testosterone concentration was found to be the most frequently abnormal biochemical marker for PCOS, and the combination of testosterone, androstenedione, or luteinizing hormone (LH) was raised in 86% of women with PCOS 5.
• The use of LH/FSH ratio as a biochemical criterion for diagnosis of PCOS should be abandoned due to its low sensitivity 5.

Hyperprolactinemia and PCOS

• Hyperprolactinemia is common in women of reproductive age and may partially mimic the clinical phenotype of PCOS, but the simultaneous finding of both conditions is not rare 6.
• The metoclopramide test can be a helpful tool to discriminate pituitary causes from other etiologies of hyperprolactinemia in women with PCOS 6.